ID |
Date |
Author |
Type |
Category |
Subject |
48
|
Thu May 27 17:49:02 2010 |
Aidan | Electronics | Hartmann sensor | Hartmann sensor cooling fins added - base piece added |
Back to Configuration 1 again - this time the fins were bolted very securely to the camera.
7:25 PM - [about 2 hours later] - Digitizer = 39.7C, Sensor = 31.4C, Ambient = 19.0C
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Attachment 1: HWS_CONFIG1-tight.jpg
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50
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Wed Jun 16 11:47:11 2010 |
Aidan | Misc | Hartmann sensor | Spot displacement maps - temperate sensitivity tests - PRISM |
I think that the second plot is just showing PRISM and converting it to its radial components. This is due to the fact that the sign of the spot displacement on the LHS is the opposite of the sign of the spot displacement on the RHS. For spherical or cylindrical power, the sign of the spot displacement should be the same on both the RHS and the LHS.
I've attached a Mathematica PDF that illustrates this.
Quote: |
Results of initial measurement of temperature sensitivity of Hartmann sensor
"Cold" images were taken at the following temperature:
| before | 32.3 | 45.3 | 37.0 |
| after | 32.4 | 45.6 | 37.3 |
"Hot" Images were taken at the following temperature:
| before | 36.5 | 48.8 | 40.4 |
| after | 36.4 | 48.8 | 40.4 |
"before" are the temperatures just before taking 5000 images, and "after" are
the temperatures just after taking the images. First column is the temperature
measured using the IR temp sensor pointed at the heat sink, the second column the
camera temperature, and the third column the sensor board temperature.
Temperature change produced by placing a "hat" over the top of the HP assembly and the top of the heatsinks.
Averaged images "cool" and "hot" were created using 200 frames (each).
Aberration parameter values are as follows:
Between cool and hot images (cool spots - hot spots)
p: 4.504320557133363e-005
al: 0.408248504544179
phi: 0.444644135542724
c: 0.001216006036395
s: -0.002509569677737
b: 0.054773177423349
be: 0.794567342929695
a: -1.030687344054648
Between cool images only
p: 9.767143368103721e-007
al: 0.453972584677992
phi: -0.625590459774765
c: 2.738206187344315e-004
s: 1.235384158257808e-006
b: 0.010135170457321
be: 0.807948378729832
a: 0.256508288049258
Between hot images only
p: 3.352035441252169e-007
al: -1.244075541477539
phi: 0.275705676833192
c: -1.810992355666772e-004
s: 7.076678388064736e-005
b: 0.003706221758158
be: -0.573902879552339
a: 0.042442307609231
Attached are two contour plots of the radial spot displacements, one between
cool and hot images, and the other between cool images only. The color
bars roughly indicate the values of maximum and minimum spot
displacements.
Possible causes:
1. anisotropy of the thermal expansion of the invar foil HP caused by the rolling
2. non-uniform clamping of the HP by the clamp plate
3. vertical thermal gradient produced by the temperature raising method
4. buckling of the HP due to slight damage (dent)
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Attachment 1: Prism_as_radial_vector.pdf
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56
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Wed Jun 23 06:49:48 2010 |
Aidan | Misc | Hartmann sensor | SURF Log -- Day 5, more Hartmann image preliminary analysis |
Nice work!
Quote: |
Today I spoke with Dr. Brooks and got a rough outline of what my experiment for the next few weeks will entail. I'll be getting more of the details and getting started a bit more, tomorrow, but today I had a more thorough look around the Hartmann lab and we set up a few things on the optical table. The OLED is now focused through a microscope to keep the beam from diverging quite as much before it hits the sensor, and the beam is roughly aligned to shine onto the Hartmann plate. The Hartmann images currently look like this (on a color scale of intensity):

Where this image was taken with the camera set to exposure time 650 microseconds, frequency 58Hz. The visible 'streaks' on the image are believed to possibly be an artifact of the camera's data acquisition process.
I tested to see whether the same 'flickering' is present in images under this setup.
For frequency kept at 58Hz, the following statistics were found from a 200x200 pixel box within series of 10 images taken at different exposure times. Note that the range on the plot has been reduced to the region near the relevant feature, and that this range is not being changed from image to image:
750 microseconds:

1000 microseconds:

1500 microseconds:

2000 microseconds:

3000 microseconds:

4000 microseconds:

5000 microseconds. Note that the background level is approaching the level of the feature:

6000 microseconds. Note that the axis setup is not restricted to the same region, and that the background level exceeds the level range of the feature. This demonstrates that the 'feature' disappears from the plot when the plot does not include the specific range of ~115-130:

When images containing the feature intensities are averaged over a greater number of images, the plot takes on the following appearance (for a 200x200 box within a series of 100 images, 3000us exposure time):

This pattern changes a bit when averaged over more images. It looks as though this could, perhaps, just be the result of the decrease in the standard deviation of the standard deviations in each pixel resulting from the increased number of images being considered for each pixel (that is, the line being less 'spread out' in the y-axis direction).
To demonstrate that frequency doesn't have any effect, I got the following plots from images where I set the camera to different frequencies then set the exposure time to 3000us (I wouldn't expect this to have any effect, given the previous images, but these appear to demonstrate that the 'feature' does not vary with time):
Set to 30Hz:

Set to 1Hz:

To make sure that something weird wasn't going on with my algorithm, I did the following: I constructed a 10-component vector of random numbers. Then, I concatenated that vector besides itself ten times. Then, I concatenated that vector into a 3D array by scaling the 2D vector with ten different integer multiples, ensuring that the standard deviations of each row would be integer multiples of each other when the standard deviation was found along the direction of the random change (I chose the integer multiples to ensure that some of these values would fall within the range of 115-130). Thus, if my function wasn't making any weird mistakes, I would end up with a linear plot of standard deviation vs. mean, with a slope of 1. When the array was inputted into the function with which the previous plots were found, the output plot was indeed observed to be linear, and a least squares regression of the mean/deviation data confirmed that the slope was exactly 1 and the intercept exactly 0. So I'm pretty certain that the feature observed in these plots is not any sort of 'artifact' of the algorithm used to analyze the data (and all the functions are pretty simple, so I wouldn't expect it to be, but it doesn't hurt to double-check).
I would conjecture from all of this that the observed feature in the plots is the result of some property of the CCD array or other element of the camera. It does not appear to have any dependence on exposure time or to scale with the relative overall intensity of the plots, and, rather, seems to depend on the actual digital number read out by the camera. This would suggest to me, at first glance, that the behavior is not the result of a physical process having to do with the wavefront.
EDIT: Some late-night conjecturing: Consider the following,
I don't know how the specific analog-to-digital conversion onboard the camera works, but I got to thinking about ADCs. I assume, perhaps incorrectly, that it works on roughly the same idea as the Flash ADCs that I dealt with back in my Digital Electronics class -- that is, I don't know if it has the same structure (a linear resistor ladder hooked up to comparators which compare the ladder voltages to the analog input, then uses some comb logic circuit which inputs the comparator outputs and outputs a digital level) but I assume that it must, at some level, be comparing the analog input to a number of different voltage thresholds, considering the highest 'threshold' that the analog input exceeds, then outputting the digital level corresponding to that particular threshold voltage.
Now, consider if there was a problem with such an ADC such that one of the threshold voltages was either unstable or otherwise different than the desired value (for a Flash ADC, perhaps this could result from a problem with the comparator connected to that threshold level, for example). Say, for example, that the threshold voltage corresponding to the 128th level was too low. In that case, an analog input voltage which should be placed into the 127th level could, perhaps, trip the comparator for the 128th level, and the digital output would read 128 even when the analog input should have corresponded to 127.
So if such an ADC was reading a voltage (with some noise) near that threshold, what would happen? Say that the analog voltage corresponded to 126 and had noise equivalent to one digital level. It should, then, give readings of 125, 126 or 127. However, if the voltage threshold for the 128th level was off, it would bounce between 125, 126, 127 and 128 -- that is, it would appear to have a larger standard deviation than the analog voltage actually possessed.
Similarly, consider an analog input voltage corresponding to 128 with noise equivalent to one digital level. It should read out 127, 128 and 129, but with the lower-than-desired threshold for 128 it would perhaps read out only 128 and 129 -- that is, the standard deviation of the digital signal would be lower for points just above 128.
This is very similar to the sort of behavior that we're seeing!
Thinking about this further, I reasoned that if this was what the ADC in the camera was doing, then if we looked in the image arrays for instances of the digital levels 127 and 128, we would see too few instances of 127 and too many instances of 128 -- several of the analog levels which should correspond to 127 would be 'misread' as 128. So I went back to MATLAB and wrote a function to look through a 1024x1024xN array of N images and, for every integer between an inputted minimum level and maximum level, find the number of instances of that level in the images. Inputting an array of 20 Hartmann sensor images, along with minimum and maximum levels of 50 and 200, gave the following:

Look at that huge spike at 128! This is more complex of behavior than my simple idea which would result in 127 having "too few" values and 128 having "too many", but to me, this seems consistent with the hypothesis that the voltage threshold for the 128th digital level is too low and is thus giving false output readings of 128, and is also reducing the number of correct outputs for values just below 128. And assuming that I'm thinking about the workings of the ADC correctly, this is consistent with an increase in the standard deviation in the digital level for values with a mean just below 128 and a lower standard deviation for values with a mean just above 128, which is what we observe.
This is my current hypothesis for why we're seeing that feature in the plots. Let me know what you think, and if that seems reasonable.
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59
|
Fri Jun 25 10:47:08 2010 |
Aidan | Misc | aLIGO Modeling | Uploaded aLIGO axicon+ITM COMSOL model to the 40m SVN |
I added a COMSOL model of the aLIGO ITM being heated by an axicon-formed annulus to the 40m SVN. The model assumes a fixed input beam size into an axicon pair and then varies the distance between the axicons. The output is imaged onto the ITM with varying magnitudes. The thermal lens is determined in the ITM and added to the self-heating thermal lens (assuming 1W absorption, I think - need to check). The power in the annulus is varied until the sum of the two thermal lenses scatters the least amount of power out of the TEM00 mode of the IFO.
https://nodus.ligo.caltech.edu:30889/svn/trunk/comsol/TCS/aLIGO/
The results across the parameter space (axicon separation and post-axicon-magnification) are attached. These were then mapped from this space to the space of annulus thickness vs annulus diameter, (see elog here).
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Attachment 1: aLIGO_axicon_spacing_post-magnification_optimization.jpg
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60
|
Fri Jun 25 10:59:43 2010 |
Aidan | Misc | aLIGO Modeling | Uploaded aLIGO axicon+ITM COMSOL model to the 40m SVN |
Here are the results in the annulus thickness vs annulus diameter space ...
Quote: |
I added a COMSOL model of the aLIGO ITM being heated by an axicon-formed annulus to the 40m SVN. The model assumes a fixed input beam size into an axicon pair and then varies the distance between the axicons. The output is imaged onto the ITM with varying magnitudes. The thermal lens is determined in the ITM and added to the self-heating thermal lens (assuming 1W absorption, I think - need to check). The power in the annulus is varied until the sum of the two thermal lenses scatters the least amount of power out of the TEM00 mode of the IFO.
https://nodus.ligo.caltech.edu:30889/svn/trunk/comsol/TCS/aLIGO/
The results across the parameter space (axicon separation and post-axicon-magnification) are attached. These were then mapped from this space to the space of annulus thickness vs annulus diameter, also attached.
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Attachment 1: Screen_shot_2010-06-25_at_11.01.38_AM.png
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66
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Tue Jul 20 15:45:51 2010 |
Aidan | Computing | General | Add fixed IP addresses to local machines in TCS lab |
http://nodus.ligo.caltech.edu:8080/AdhikariLab/859 |
67
|
Tue Jul 20 18:13:06 2010 |
Aidan | Computing | General | Added TCS channels to frame builder |
http://nodus.ligo.caltech.edu:8080/AdhikariLab/860
contents of tcs_daq: /target/TCS_westbridge.db
grecord(ai,"C4:TCS-ATHENA_ADC0")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S0")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC1")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S1")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC2")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S2")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC3")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S3")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC4")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S4")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC5")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S5")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC6")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S6")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC7")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S7")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC8")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S8")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC9")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S9")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC10")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S10")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC11")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S11")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC12")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S12")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC13")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S13")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC14")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S14")
field(SCAN,".1 second")
}
grecord(ai,"C4:TCS-ATHENA_ADC15")
{
field(DTYP,"ATHENA")
field(INP,"#C0 S15")
field(SCAN,".1 second")
}
grecord(ao,"C4:TCS-ATHENA_DAC0")
{
field(DTYP,"ATHENA")
field(OUT,"#C0 S0")
field(HOPR,"32768")
field(LOPR,"-32768")
}
grecord(ao,"C4:TCS-ATHENA_DAC1")
{
field(DTYP,"ATHENA")
field(OUT,"#C0 S1")
}
grecord(bi,"bi0")
{
field(SCAN,".1 second")
field(DTYP,"ATHENA")
field(INP,"#C0 S8")
field(ZNAM,"zero")
field(ONAM,"one")
}
grecord(bo,"C4:TCS-ATHENA_BO0")
{
field(DOL,"HeartBeat")
field(OMSL,"closed_loop")
field(DTYP,"ATHENA")
field(OUT,"#C0 S1")
field(ZNAM,"zero")
field(ONAM,"one")
}
grecord(bo,"C4:TCS-ATHENA_BO1")
{
field(DOL,"LevelAlarm")
field(OMSL,"closed_loop")
field(DTYP,"ATHENA")
field(OUT,"#C0 S2")
field(ZNAM,"zero")
field(ONAM,"one")
}
grecord(bo,"C4:TCS-ATHENA_BO2")
{
field(DOL,"Pressure_OK")
field(OMSL,"closed_loop")
field(DTYP,"ATHENA")
field(OUT,"#C0 S3")
field(ZNAM,"zero")
field(ONAM,"one")
}
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68
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Thu Jul 22 11:02:59 2010 |
Aidan | Computing | General | Restarted hartmann machine |
hartmann had started responding to requests to log-in with the a request to change the password. Attempts to change the password proved unsuccessful. I tried to access the machine locally to change the password but I couldn't the display started, so I had to reboot it.
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70
|
Fri Jul 23 10:33:08 2010 |
Aidan | Computing | Hartmann sensor | Dalsa camera ADC 8th digitizer error |
I plotted a histogram of the total intensity of the Hartmann sensor when illuminated and found that the 128 count problem extends all the way up through the distribution. This isn't unreasonable since that digitizer is going to be called on mutliple times.
First things first, the value of 128 equals a 1 in the 8th digitizer, so for a 16-bit number in binary, it looks like this: 0000 0000 1000 0000 and in hex-code 080
The values of the peaks in the attached distribution are as follows:
Number of counts |
Hex Code |
128
|
080 |
384 |
180 |
640 |
280 |
896 |
380 |
1152 |
480 |
1408 |
580 |
1664 |
680 |
1920 |
780 |
2176 |
880 |
2432 |
980 |
2688 |
A80 |
2944 |
B80 |
3200 |
C80 |
|
Attachment 1: histogram_of_dalsa_intensity.pdf
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71
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Fri Jul 23 12:33:51 2010 |
Aidan | Computing | Hartmann sensor | Invar clamp scatter |
I illuminated the Hartmann sensor with the output of a fiber placed ~1m away.
I noticed that the illumination was not uniform, rather there was some sort of 'burst' or 'star' right near the center of the image. This turned out to be due to the Hartmann plate clamps - it disappeared when I removed those. It appears that there is scatter off the inner surface of the holes through the clamp plates. I'm not sure if it's from the front or back plates.
Needs further investigation ... |
72
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Fri Jul 23 12:38:58 2010 |
Aidan | Computing | Hartmann sensor | Images for Dalsa |
Attached are the background and 80% illumination (~uniform spatially uniform) images that Dalsa requested.
Note that the gain of the taps does not appear to be balanced.
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Attachment 1: dark_0000.jpg
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Attachment 2: bright_0000.jpg
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73
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Fri Jul 23 19:52:49 2010 |
Aidan | Computing | Hartmann sensor | Dalsa camera ADC 8th digitizer error |
I've attached an image that shows the locations of those pixels that record a number of counts = (2*n-1)*128.
The image is the sum of 200 binary images where pixels are given values of 1 if their number of counts = (2*n-1)*128 and 0 otherwise.
The excess of counts is clearly coming from the left hand tap. This is good news because the two taps have independent ADCs and it suggests that it is only a malfunctioning ADC on the LHS that is giving us this problem.
Quote: |
I plotted a histogram of the total intensity of the Hartmann sensor when illuminated and found that the 128 count problem extends all the way up through the distribution. This isn't unreasonable since that digitizer is going to be called on mutliple times.
First things first, the value of 128 equals a 1 in the 8th digitizer, so for a 16-bit number in binary, it looks like this: 0000 0000 1000 0000 and in hex-code 080
The values of the peaks in the attached distribution are as follows:
Number of counts |
Hex Code |
128
|
080 |
384 |
180 |
640 |
280 |
896 |
380 |
1152 |
480 |
1408 |
580 |
1664 |
680 |
1920 |
780 |
2176 |
880 |
2432 |
980 |
2688 |
A80 |
2944 |
B80 |
3200 |
C80 |
|
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Attachment 1: image-location-of-excess_pixel_count_pixels.jpg
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74
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Sat Jul 24 10:50:14 2010 |
Aidan | Electronics | Hartmann sensor | Lab Temperature and HWS temperature: pre-indium |
Hour-long trend puts the lab temperature at 19.51C
Dalsa temperature:
Camera Temperature on Digitizer Board: 41.0 Celsius
Camera Temperature on Sensor Board: 32.9 Celsius
OK>
There is currently no Indium in the HWS.
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75
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Sun Jul 25 16:24:56 2010 |
Aidan | Computing | SLED | Superlum SLED test integrated with DAQ - new channel names |
I added some new channels to the Athena DAQ that record the diagnostic channels from the Superlum SLED.
- C4:TCS-ATHENA_I_SET_VOLTS: - the set current signal in Volts (1V = 1A)
- C4:TCS-ATHENA_I_ACTUAL_VOLTS: - a signal proportional to the actual current flowing to the SLED (1V = 1A)
- C4:TCS-ATHENA_I_LIM_VOLTS: - the current limit signal in volts (1V = 1A)
- C4:TCS-ATHENA_TEMP_SENS_V: - the signal from the on-board temperature sensor [thermistor] (1V = 10kOhm ?)
- C4:TCS-ATHENA_PD_VOLTAGE: - the signal from the on-board photodetector (1V = 1A?)
The ioc that handles the EPICS channels is on tcs_daq(10.0.1.34) in /target/TCS_westbridge.db
The channels are added to the frame builder in /cvs/cds/caltech/chans/daq/C4TCS.ini
Currently, the driver for the SLED is ON but the current to the SLED is off. This is to check that the zero value of the PD_VOLTAGE signal doesn't wander.
Also, the input noise of the Athena is around +/- 10 counts (where 2^15 counts = 10V) which is a pretty poor 3mV. |
76
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Mon Jul 26 09:42:30 2010 |
Aidan | Computing | SLED | Long term test on SLED started - Day 0 |
I set up the SLED to test its long term performance. The test began, after a couple of false starts, around 9:15AM this morning.
The output of the fiber-optic patch cord attached to the SLED is illuminating a photo-detector. The zero-level on the PD was 72.7mV (with the lights on). Once the PD was turned on the output was ~5.50 +/- 0.01V. This is with roughly 900uW exiting the SLED.
The instructions from Superlum suggest limiting the amount of power coupled back into the fiber to less than 3%. With the current setup, the fiber is approximately 2" from the photodetector. What is the power coupled back into the fiber?
Assume a worst case of 100% of the light reflected from the PD, the wavelength is 830nm and a waist size of about 6um radius at the output of the fiber. The beam size at 4" (from the fiber output to the PD and back again) or ~100mm from the fiber is about 4.4mm radius. Therefore about (6um/4.4mm)^2 or ~2ppm will be coupled back into the fiber. This is sufficiently small.
The attached plots from dataviewer show measurements from the SLED (on-board photodetector, on-board temperature sensor, current setpoint, current limit, current to diode) over the last 15 hours. |
Attachment 1: SLED_superlum_long_term_test_0001A.pdf
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Attachment 2: SLED_superlum_long_term_test_0001B.pdf
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77
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Mon Jul 26 12:17:25 2010 |
Aidan | Electronics | Hartmann sensor | Added Indium to HWS |
I added some 0.004" thick indium sheet to the copper heat spreaders and and the heat sinks on the side of the HWS to try and improve the thermal contact. Once installed the steady state temperature of the sensor was the same as before. It's possible that the surface of the copper is even more uneven than 0.004".
|
Attachment 1: indium-01.jpg
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Attachment 2: indium-03.jpg
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Attachment 3: indium-05.jpg
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Attachment 4: indium-02.jpg
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Attachment 5: indium-04.jpg
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79
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Tue Jul 27 08:31:10 2010 |
Aidan | Electronics | SLED | Long term SLED test - Day 1 |
The measurement from the on-board PD of the Superlum SLED seems to be falling. This effect started around 5PM last night which is right about the time we moved the position of the PD that the SLED is illuminating on the optical table (via optical fiber).
Curiously, the current set point and delivered current to the SLED are dropping as well. |
Attachment 1: SLED_superlum_long_term_test_0002A.pdf
|
|
80
|
Wed Jul 28 18:32:12 2010 |
Aidan | Electronics | SLED | SLED long term test - Day 2 |
Here's the data from the last 2 1/2 days of running the SLED. The decrease in photo-current measured by the on-board photo-detector is consistent with the decrease in the current set-point and the delivered current, but it is not clear why these should be changing.
Strictly speaking I should add some analysis that shows that delta_PD_voltage_measured = delta_I_set_measured * [delta_PD_voltage/delta_I_set (I_set)]_calculated ... |
Attachment 1: SLED_superlum_long_term_test_0003A.pdf
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81
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Thu Jul 29 10:09:19 2010 |
Aidan | Electronics | SLED | SLED long term test - Day 2 |
I've attached the Acceptance Test Report data from SUPERLUM for this SLED. I've also determined the expected percentage decrease in power/photo-current per mA drop in forward current.
The measured decrease in forward current over the last 2 1/2 days is around 1.4mA from around 111mA. The expected drop in power is thus (4.5% per mA)*(1.4mA) = 6.3%.
The drop in photo-current is around 37.5mA to 35mA = 2.5mA. The percentage drop is around 100*(2.5mA)/(36.3mA) = 6.9%.
Therefore, the drop in measured power is consistent with what we would expect given the decrease in forward current (which is consistent with the drop in the set point). Why the set-point is dropping is still a mystery.
Quote: |
Here's the data from the last 2 1/2 days of running the SLED. The decrease in photo-current measured by the on-board photo-detector is consistent with the decrease in the current set-point and the delivered current, but it is not clear why these should be changing.
Strictly speaking I should add some analysis that shows that delta_PD_voltage_measured = delta_I_set_measured * [delta_PD_voltage/delta_I_set (I_set)]_calculated ...
|
|
Attachment 1: superlum_SLED_ATR.pdf
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82
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Fri Jul 30 10:04:54 2010 |
Aidan | Computing | Hartmann sensor | Restarted the HWS EPICS channels |
Restarted the HWS EPICS channels on hartmann with the following command:
/cvs/opt/epics-3.14.10-RC2-i386/base/bin/linux-x86/softIoc -S HWS.cmd &
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83
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Fri Jul 30 11:01:31 2010 |
Aidan | Computing | Hartmann sensor | EPICS softIoc alias |
I added an alias HWSIoc to controls which can be used to start the HWS EPICS softIoc.
alias HWSIoc='/cvs/cds/caltech/target/softIoc/startHWSIOC.sh'
and the bash script is:
#!/bin/bash
cd /cvs/cds/caltech/target/softIoc
/cvs/opt/epics-3.14.10-RC2-i386/base/bin/linux-x86/softIoc -S /cvs/cds/caltech/
target/softIoc/HWS.cmd &
cd -
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85
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Fri Jul 30 19:22:24 2010 |
Aidan | Computing | EPICS | Waveform Channel Access for storing centroids |
A waveform channel was added to the HWS softIoc on hartmann. This allows arrays of data to be stored in a single channel. It's not clear whether it is storing this data as a set of number or strings. However, the values can be changed by the following command:
caput -a -n C4:TCS-HWS_CENTROIDSX 5 1,2,3,4,5
Although the <no of values> entry doesn't seem to actual enforce anything - you can have more or less values than this in the array and they are still added to the channel. What does seem to be necessary is no spaces between the commas and the values of the array.
This also works:
[controls@fb1 cds]$ caput -a -n C4:TCS-HWS_CENTROIDSX 2 1,2,3n
Old : C4:TCS-HWS_CENTROIDSX 1,2,35.4342
New : C4:TCS-HWS_CENTROIDSX 1,2,3n
which suggests that this is really a string variable - even with the -n enforce. The cainfo command suggests this as well.
[controls@fb1 cds]$ cainfo C4:TCS-HWS_CENTROIDSX
C4:TCS-HWS_CENTROIDSX
State: connected
Host:
Access: read, write
Data type: DBR_STRING (native: DBF_STRING)
Element count: 1
Usage: caput [options] <PV name> <PV value>
caput -a [options] <PV name> <no of values> <PV value> ...
-h: Help: Print this message
Channel Access options:
-w <sec>: Wait time, specifies longer CA timeout, default is 1.000000 second
Format options:
-t: Terse mode - print only sucessfully written value, without name
Enum format:
Default: Auto - try value as ENUM string, then as index number
-n: Force interpretation of values as numbers
-s: Force interpretation of values as strings
Arrays:
-a: Put array
Value format: number of requested values, then list of values
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86
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Fri Jul 30 21:19:05 2010 |
Aidan | Computing | EPICS | Waveform Channel Access for storing centroids |
After some discussion with Frank we figured out how to edit the record type in HWS.db so that the waveform/array channel actually behaved like a numerical array and not like a single string. This just involved defining the data type and the element count in the record definition, like so:
record(waveform, "C4:TCS-HWS_CENTROIDSX")
{
field(EGU,"PIXELS")
field(HOPR,"1024")
field(LOPR,"0")
field(FTVL,"DOUBLE")
field(NELM,"1000")
}
and then when the ioc was rebooted, examination of the channel showed the following:
[controls@hartmann softIoc]$ cainfo C4:TCS-HWS_CENTROIDSX
C4:TCS-HWS_CENTROIDSX
State: connected
Host: hartmann:5064
Access: read, write
Data type: DBR_DOUBLE (native: DBF_DOUBLE)
Element count: 1000
[controls@hartmann softIoc]$ caput -a -n C4:TCS-HWS_CENTROIDSX 10 1 2 3 4 5 6 7 8 9 10 11 12 13.1
Old : C4:TCS-HWS_CENTROIDSX 13 1 2 3 4 5 6 7 8 9 10 11 12 13.1
New : C4:TCS-HWS_CENTROIDSX 13 1 2 3 4 5 6 7 8 9 10 11 12 13.1
[controls@hartmann softIoc]$ caget C4:TCS-HWS_CENTROIDSX
C4:TCS-HWS_CENTROIDSX 1000 1 2 3 4 5 6 7 8 9 10 11 12 13.1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Quote: |
A waveform channel was added to the HWS softIoc on hartmann. This allows arrays of data to be stored in a single channel. It's not clear whether it is storing this data as a set of number or strings. However, the values can be changed by the following command:
caput -a -n C4:TCS-HWS_CENTROIDSX 5 1,2,3,4,5
Although the <no of values> entry doesn't seem to actual enforce anything - you can have more or less values than this in the array and they are still added to the channel. What does seem to be necessary is no spaces between the commas and the values of the array.
This also works:
[controls@fb1 cds]$ caput -a -n C4:TCS-HWS_CENTROIDSX 2 1,2,3n
Old : C4:TCS-HWS_CENTROIDSX 1,2,35.4342
New : C4:TCS-HWS_CENTROIDSX 1,2,3n
which suggests that this is really a string variable - even with the -n enforce. The cainfo command suggests this as well.
[controls@fb1 cds]$ cainfo C4:TCS-HWS_CENTROIDSX
C4:TCS-HWS_CENTROIDSX
State: connected
Host:
Access: read, write
Data type: DBR_STRING (native: DBF_STRING)
Element count: 1
Usage: caput [options] <PV name> <PV value>
caput -a [options] <PV name> <no of values> <PV value> ...
-h: Help: Print this message
Channel Access options:
-w <sec>: Wait time, specifies longer CA timeout, default is 1.000000 second
Format options:
-t: Terse mode - print only sucessfully written value, without name
Enum format:
Default: Auto - try value as ENUM string, then as index number
-n: Force interpretation of values as numbers
-s: Force interpretation of values as strings
Arrays:
-a: Put array
Value format: number of requested values, then list of values
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87
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Sat Jul 31 11:54:20 2010 |
Aidan | Computing | SLED | SLED Test Day 5 - Re-tuned current set-point control voltage |
Main Points
- Re-set SLED current set-point control voltage to 0.111V
- SLED current set-point voltage drops by about 5mV when the SLED is dis-engaged
- Resetting was around 11:45AM PDT 31st-Jul-2010
I turned off the SLED for 10s and reset the current set-point voltage (read using a mutlimeter and probing a couple of pins at the back of the driver board). The initial voltage when the test started on Monday was 0.111V when the SLED was engaged. This drooped to 0.109V over the week and there was a corresponding (but possible not resulting) drop in on-board photo-diode voltage. When the SLED was disengaged the set-point current control voltage dropped to 0.104V. I turned the LP pot on the front of the SLED driver board until the multimeter read 0.106V and re-engaged the SLED. The curernt set-point voltage then read 0.111V, occasionally popping up to 0.112V for a moment or two.
The DC Power Supply to the SLED reads 8.9V with 0.26A current being drawn. |
89
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Mon Aug 9 10:58:37 2010 |
Aidan | Laser | SLED | SLED 15-day trend |
Here's a plot of the 15-day output of the SLED.
Currently there is an 980nm FC/APC fiber-optic patch-cord attached to the SLED. It occurred to me this morning that even though the patch cord is angle-cleaved, there may be some back-reflection than desired because the SLED output is 830nm (or thereabouts) while the patch cord is rated for 980nm.
I'm going to turn off the SLED until I get an 830nm patch-cord and try it then.
Correction: I removed the fiber-optic connector and put the plastic cap back on the SLED output. The mode over-lap (in terms of area) from the reflection off the cap with the output from the fiber is about 1 part in 1000. So even with 100% reflection, there is less than the 0.3% danger level coupled back into the fiber. The SLED is on again. |
Attachment 1: SLED_superlum_long_term_test_0005A_annotated_15-day_result.pdf
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90
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Tue Aug 17 16:31:55 2010 |
Aidan | Things to Buy | Laser | Bought a laser diode from Thorlabs for HWS |
http://www.thorlabs.com/thorProduct.cfm?partNumber=CPS180
I bought this laser diode from Thorlabs today to try the current modulation trick Phil and I discussed last Friday.
That is:
- Accept that there will be interference fringes on the Hartmann sensor probe beam with a laser diode source (especially if the probe beam is the retro-reflection from a Michelson interferometer with a macroscopic arm length difference)
- Modulate the current of the laser diode source to vary its wavelength by a few hundreds on nm. Do this on a time scale that is much faster than the exposure time for a Hartmann sensor measurement
- The contrast of the interference fringes should average out and the exposure should appear to be the sum of two incoherent beams.
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92
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Wed Aug 18 18:38:11 2010 |
Aidan | Computing | Hartmann sensor | Hartmann sensor code |
I downloaded and tested revision 47 of the Adelaide Hartmann sensor code from the SVN (https://trac.ligo.caltech.edu/Hartmann_Sensor/browser/users/won/HS_OO?rev=47). After giving it the correct input filenames it centroided the Hartmann sensor images pretty seamlessly. The output and code is attached below.
The code takes two Hartmann images. Locates the centroids in both instances and then determines the displacements of all the centroids between the two images. The locations of the centroids are plotted in a diagram and the x- and y- centroid displacements are plotted vs the index of each centroid.
The following comments are output on the command line in MATLAB:
>> test_HS_Classes
Current plot held
Current plot released
----------------------------------------------------------------
Obtained reference and test centroids.
Number of centroids in reference centroids = 951
average position of reference centroids:
x = 506.39615297 y = 512.890603168
Number of centroids in test centroids = 951
average position of test centroids:
x = 506.396160891 y = 512.892513673
----------------------------------------------------------------
HWS_code_output.png - shows the output from the code: we'll need to get more labels on these plots.
HWS_input_image.png - the reference input image (using false color scale) to the Hartmann code |
Attachment 1: test_HS_Classes.m
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% test_HS_classes.m
%
% A script to test and demonstrate the usage of classes HS_Centroids and
% HS_Classes.
% (LIGO) If half_offset is set true, image and centroids won't be in
% sync in the scatter plot.
% Input parameters
background = 49.3;
... 107 more lines ...
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Attachment 2: HS_Image.m
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% HS_Image.m
%
%
% HS_Image is a class used to store and interact with images from
% Hartmann Sensor camera.
%
% An instance of the class HS_Image is also used as a property of an
% instance of the class HS_Centroids.
%
% Properties:
... 70 more lines ...
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Attachment 3: HS_Centroids.m
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% HS_Centroids.m
%
%
% HS_Centroids is a class used to generate and interact with centroids
% of Hartmann Sensor images.
%
% An instance of the class HS_Centroids holds a set of centroids of an
% image.
%
% Properties:
... 254 more lines ...
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Attachment 4: HWS_code_output.png
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Attachment 5: HWS_input_image.png
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93
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Mon Aug 23 08:43:16 2010 |
Aidan | Things to Buy | Laser | Bought a laser diode from Thorlabs for HWS |
It arrived on Friday.
Quote: |
http://www.thorlabs.com/thorProduct.cfm?partNumber=CPS180
I bought this laser diode from Thorlabs today to try the current modulation trick Phil and I discussed last Friday.
That is:
- Accept that there will be interference fringes on the Hartmann sensor probe beam with a laser diode source (especially if the probe beam is the retro-reflection from a Michelson interferometer with a macroscopic arm length difference)
- Modulate the current of the laser diode source to vary its wavelength by a few hundreds on nm. Do this on a time scale that is much faster than the exposure time for a Hartmann sensor measurement
- The contrast of the interference fringes should average out and the exposure should appear to be the sum of two incoherent beams.
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94
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Mon Sep 13 18:24:52 2010 |
Aidan | Laser | Hartmann sensor | Enclosure for the HWS |
I've assembled the box Mindy ordered from Newport that will house the Hartmann sensor. It's mainly to reduce ambient light, air currents and to keep the table cleaner than it would otherwise be.
We need to add a few more holes to allow access for extra cables.
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Attachment 1: 00001.jpg
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Attachment 2: 00002.jpg
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Attachment 3: 00003.jpg
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Attachment 4: 00005.jpg
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95
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Tue Sep 28 10:41:32 2010 |
Aidan | Laser | Hartmann sensor | Aligning HWS cross-sample experiment - polarization issues |
I'm in the process of aligning the cross-sampling experiment for the HWS. I've put the 1" PBS cube into the beam from the fiber-coupled SLED and found that the split between s- and p-polarizations is not 50-50. In fact, it looks more like 80% reflected and 20% transmitted. This will, probably, be due to the polarization-maintaining patch-cord that connects to the SLED. I'll try switching it out with a non-PM maintaining fiber.
Later ...
That worked. |
96
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Tue Sep 28 17:53:40 2010 |
Aidan | Laser | Hartmann sensor | Crude alignment of cross-sampling measurement |
I've set up a crude alignment of the cross-sampling system (optical layout to come). This was just a sanity check to make sure that the beam could successfully get to the Hartmann sensor. The next step is to replace the crappy beam-splitter with one that is actually 50/50.
Attached is an image from the Hartmann sensor. |
Attachment 1: 2010_09_28-HWS_cross_sample_expt_crude_alignment_01.pdf
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97
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Wed Sep 29 16:49:36 2010 |
Aidan | Laser | Hartmann sensor | Cross-sampling experiment power budget |
I've been setting up the cross-sampling test of the Hartmann sensor, Right now I'm waiting on a 50/50 BS so I'm improvising with a BS for 1064nm.
The output from the SLED (green-beam @ 980nm) is around 420uW (the beam completely falls on the power meter.) There are a couple of irises shortly afterwards that cut out a lot of the power - apparently down to 77uW (but the beam is larger than the detection area of the power meter at this point - by ~50%). The BS is not very efficient on reflection and cuts down the power to 27uW (overfilled power meter). The measurement of 39uW is near a focus and the power meter captures the whole beam. There is a PBS cube that is splitting the beam unequally between s- and p-polarizations (I think this is due to uneven reflections for s- and p-polarizations from the 1064nm BS). The beam is retro-reflected back to the HWS where about 0.95uW makes it to the detector.
There is a 1mW 633nm laser diode that is used to align the optical axis. There are two irises that are used to match the optical axis of the laser diode and the SLED output.
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Attachment 1: 00001.jpg
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98
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Mon Oct 4 19:44:03 2010 |
Aidan | Laser | Hartmann sensor | Cross-sampling experiment - two beams on HWS |
I've set up the HWS with the probe beam sampling two optics in a Michelson configuration (source = SLED, beamsplitter = PBS cube). The return beams from the Michelson interferometer are incident on the HWS. I misaligned the reflected beam from the transmitted beam to create two Hartmann patterns, as shown below.
The next step is to show that the centroiding is a linear superposition of these two wavefronts. |
Attachment 1: test001_two_beams_on_HWS.pdf
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99
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Tue Oct 5 12:51:16 2010 |
Aidan | Laser | Hartmann sensor | Variable power in two beams of cross-sampling experiment |
The SLED in the cross-sampling experiment produces unpolarized light at 980nm. So I added a PBS after the output and then a HWP (for 1064nm sadly) after that. In this way I produced linearly p-polarized light from the PBS. Then I could rotate it to any angle by rotating the HWP. The only drawback was that the HWP was only close to half a wave of retardation at 980nm. As a result, the output from this plate became slightly elliptically polarized.
The beam then went into another PBS which split it into two beams in a Michelson-type configuration (REFL and TRANS beams) - see attached image. By rotating the HWP I could vary the relative amount of power in the two arms of the Michelson. The two beams were retro-reflected and we then incident onto a HWS.
I measured the power in the REFL beam relative to the total power as a function of the HWP angle. The results are shown in the attached plot.
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Attachment 1: test002_two_beams_on_HWS_analyze.pdf
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Attachment 2: Hartmann_Enclosure_Diagram__x-sampling.png
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102
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Tue Nov 30 11:01:19 2010 |
Aidan | Computing | General | New workstation added in TCS Lab. New Static IP |
I added a workstation at 10.0.1.26 in the TCS lab. |
103
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Tue Nov 30 11:03:19 2010 |
Aidan | Computing | Frame Grabber | EDT frame grabber works under Ubuntu |
The new machine in the TCS lab is running Ubuntu. I installed the frame-grabber into it and, after loading the configuration file for the camera, was able to access the serial port on the camera and also was able to record a properly formatted image from the Hartmann sensor. |
104
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Tue Jan 25 16:38:16 2011 |
Aidan | Electronics | Pre-amplifier | L1 TCSY ISS Board transfer function |
I measured the AC and DC channel transfer functions of the eLIGO L1 TCSY ISS board for PD1 and PD2. The gain is quite high on the AC channels so I added +40dB of attenuation to the source from the SR785. As Frank pointed out, even though this isn't exactly +40dB at low frequencies, it still attenuates and that attenuation is common to both the input to the Channel 1 of the SR785 and the input to the ISS board.
The results are shown in the attached plot. I didn't bother including the phase, I'm just interested in the magnitude for calibration purposes.
The original data files from the SR785 are attached below:
Channel Name |
Filename |
L1 TCSY PD1 - AC |
SRS003.78D |
L1 TCSY PD2 - AC |
SRS004.78D |
L1 TCSY PD1 - DC |
SRS005.78D |
L1 TCSY PD2 - DC |
SRS006.78D |
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Attachment 1: L1TCS_ISS_boards_transfer_functions.pdf
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Attachment 2: SRS003.78D
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Attachment 3: SRS004.78D
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Attachment 4: SRS005.78D
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Attachment 5: SRS006.78D
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105
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Tue Feb 8 13:02:26 2011 |
Aidan | Electronics | Delivery Note | Thorlabs S322C 200W power head arrived |
The 200W Thermopile power head from Thorlabs arrive today. The scanned delivery note and calibration info are attached. |
Attachment 1: Co2_200W_power_meter_delviery_note.pdf
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Attachment 2: Co2_200W_power_meter_calibration_info.pdf
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106
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Fri Feb 18 13:26:23 2011 |
Aidan | Things to Buy | Delivery Note | First parts of Bosch framing have arrived from Valin |
The first pieces of the Bosch framing have arrived from Valin Corporation. These are just small pieces such as the fasteners and the gussets. There are no custom lengths of framing yet.
The details are in the attached Packing List. [1:25PM] I haven't verified that everything is there yet.
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Attachment 1: Packing_List_01.pdf
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108
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Wed Feb 23 18:04:38 2011 |
Aidan | Things to Buy | Delivery Note | First parts of Bosch framing have arrived from Valin |
Quote: |
The first pieces of the Bosch framing have arrived from Valin Corporation. These are just small pieces such as the fasteners and the gussets. There are no custom lengths of framing yet.
The details are in the attached Packing List. [1:25PM] I haven't verified that everything is there yet.
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Another box of Bosch stuff arrived in my office. The packing list is attached |
Attachment 1: Packing_List_02.pdf
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109
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Wed Feb 23 20:18:30 2011 |
Aidan | Electronics | Hartmann sensor | Successfully re-started the Hartmann sensor |
I reattached the Hartmann Sensor to the LENOVO machine that is running Ubuntu and turned it on (it's been disconnected for a couple of months). The /opt/EDTpdv/serial_cmd was able to communicate successfully with the camera. |
111
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Thu Feb 24 13:35:41 2011 |
Aidan | Things to Buy | Delivery Note | Bosch framing has arrived |
The custom pieces of the Bosch framing have arrived. Transportation is currently moving them downstairs to the lab. The packing list is attached.
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Attachment 1: Packing_List_03.pdf
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112
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Thu Feb 24 14:20:55 2011 |
Aidan | Misc | Ring Heater | aLIGO H2 Ring Heater Pics |
Here are some pictures of the ring heater segments destined for the H2 Y-arm this year.
These still need to be put onto ResourceSpace. |
Attachment 1: aLIGO_Ring_Heaters.zip
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113
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Thu Feb 24 14:23:58 2011 |
Aidan | Lab Infrastructure | Hartmann sensor | Hartmann Sensor box cut down to size |
I reduced the height of the Hartmann sensor box. This is what it looks like now:
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Attachment 1: P1000109.jpg
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Attachment 2: P1000110.jpg
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Attachment 3: P1000111.jpg
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Attachment 4: P1000113.jpg
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114
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Mon Feb 28 17:33:07 2011 |
Aidan | Computing | Hartmann sensor | Hartmann Seidel abberation channels in frame builder |
Using the same methods as before, see below, I've added some Hartmann sensor EPICS channels to the frames.
The channels record the Hartmann sensor Probe (and Secondary) Coefficients of the Seidel aberrations (PSC, SSC) that are specified (PRISM, ALPHA, PHI, etc).
- Created
/cvs/cds/caltech/chans/daq/C4HWS.ini with the attached contents.
- Added a line to
/cvs/cds/caltech/target/fb1/master to load C4HWS.ini
- restarted the frame builder by killing
daqd
[default]
dcuid=4
datarate=16
gain=1.0
acquire=1
ifoid=0
datatype=4
slope=1.0
offset=0
units=NONE
[C4:TCS-HWSX_PSC_PRISM]
[C4:TCS-HWSX_PSC_ALPHA]
[C4:TCS-HWSX_PSC_PHI]
[C4:TCS-HWSX_PSC_CYLINDRICAL_PO]
[C4:TCS-HWSX_PSC_SPHERICAL_POWE]
[C4:TCS-HWSX_PSC_COMA]
[C4:TCS-HWSX_PSC_BETA]
[C4:TCS-HWSX_PSC_SPHERICAL_ABER]
[C4:TCS-HWSX_SSC_PRISM]
[C4:TCS-HWSX_SSC_ALPHA]
[C4:TCS-HWSX_SSC_PHI]
[C4:TCS-HWSX_SSC_CYLINDRICAL_PO]
[C4:TCS-HWSX_SSC_SPHERICAL_POWE]
[C4:TCS-HWSX_SSC_COMA]
[C4:TCS-HWSX_SSC_BETA]
[C4:TCS-HWSX_SSC_SPHERICAL_ABER]
Quote: |
I've added the digitizer and sensor board temperature readings from the HWS to the frames. This was done in the following way
1. Create a new file /cvs/cds/caltech/chans/daq/C4TCS.ini - with the channels in it - see below
2. open /cvs/cds/caltech/target/fb1/master
3. add a line that includes the C4TCS.ini file when the frame builder starts
4. restart frame-builder by killing the daq daemon - kill <process id for daqd> (this is the only thing that needs to be entered as it will automatically restart)
C4TCS.ini
[default]
dcuid=4
datarate=16
gain=1.0
acquire=1
ifoid=0
datatype=4
slope=1.0
offset=0
units=NONE
[C4:TCS-HWS_TEMP_SENSOR]
[C4:TCS-HWS_TEMP_DIGITIZER]
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115
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Mon Feb 28 17:56:32 2011 |
Aidan | Computing | Hartmann sensor | Got HWS code running and interface to EPICS |
Here are the notes from today's efforts:
- When you 'Run_HWS' in MATLAB and the camera has not been initialized, it says the camera is not accessible. Either that or you need to run 'sudo matlab' (no, sudo doesn't help)
- In Ubuntu have to run '/opt/EDTpdv/initcam -f ~/dalsa_1m60.cfg' to start the camera
- Now have to install MCA
- MCA installed by is crashing MATLAB - not sure why. Maybe its a 'sudo' problem again?
- sudo matlab has the following problem:
mca
??? Invalid MEX-file
'/home/controls/base-3-14-11/extensions/lib/linux-x86_64/mca.mexa64':
libdbStaticHost.so.3.14: cannot open shared object file: No such file or
directory.
- adjusting Makefile for MCA to include the correct suffix for a Linux based MEX file ('mexa64', not 'mexglnx') gets the program to compile correctly and then MATLAB runs MCA fine.
- Running 'Run_HWS' with EPICS running but no channels crashes the program
- copy the HWS.db file to the EPICS db location
- cannot create the matlab images folder when the program runs.
- created these manually
- program is trying to adjust the maximum pixel count - it is failing and the camera is complaining (intensity is quite low right now)
- why exposure mode 6? - requires an external SYNC signal
- can't handle low exposure - FIX THIS!!
- why is the expsoure time increased in stepwise fashion? Use algorithm!
- Commenting this out!!
- same for the secondary beam
- After running State 1 it asks to continue to State 2 - if you select 'n' the program crashes
- steered beam properly onto HWS
-----------
- continue to State 2 - 'yes' crashes the program
- HS_report is doesn't work
- commented out lines 37 to 47
- get rid of constant requests to continue [run_acquire_auto.m]
- change names of EPICS variables [done]
- add an RMS variable
- the named EPICS variables need to be dynamically named rather than statically named.
--------
run_acquire_auto.m CHANGES
0. Update sensor date: mres = 'y'
1. pres = 'n'; - don't update reference centroids
2. sres = 'n'; - don't update secondary reference centroids
3. select probe beam commented out
4. select secondary beam commented out
5. State 2B - select probe live commented out
6. set user_response = 'y' for continue
A1 - added a loopcounter that starts at zero. the first loop includes user prompts and then they're bypassed in subsequent loops.
-----------
-Seidel aberration fitting seems wrong - not resembling the integrated field
- get rid of the constant pop ups
- have a network license EPICS variable
- how many images are used for reference image?
- added a variable in run_acquire_auto.m :
- no_of_cim_ref = 200; (no_of_cim = 5 images was previous)
- changed the averaging in reference image acquisition from
- "no_of_cim" to "no_of_cim_ref"
- didn't change the take command from 5 to 200 images
- commented out lines 239-242 in run_initialize - gives a second way to start run_acquire.m
- probe and secondary beams share the probe background - deliberate?
- average all the images and save as a single matlab 16-bit array
- what is the rms noise as a function of the reference image number of averages?
------
Changing the EPICS variable names.
1. HS_WF - where Seidel coefficients are named.
- in function seidel_from
2. changed the following lines in 'run_acquire_auto.m'
%channelname = ['probe-seidel-',fn{counter}];
channelname = ['C4:TCS-HWSX_PSC_', fn{counter}];
%channelname = ['secondary-seidel-',fn{counter}];
channelname = ['C4:TCS-HWSX_SSC_', fn{counter}];
3. ammended the following code in 'run_acquire_auto.m'
maxEPICSLength = 14;
for counter = 1:length(fn)
%channelname = ['probe-seidel-',fn{counter}];
strname = upper(fn{counter});
if (numel(strname) > maxEPICSLength)
strname = strname(1:maxEPICSLength);
end
channelname = ['C4:TCS-HWSX_PSC_', strname];
probe_seidel_array{counter} = HS_EPICS(channelname);
end
-----
- bug: on restarting and pressing 'space' and enter at approximately the same times here, the program crashed:
Is it okay to assign one of the already existing handle (y or n)? y
Assigned handle 2 to the instance.
Established the connection to the channel secondary_shutter_open.
hsep_secondary =
HS_EPICS handle
Properties:
channelname: 'secondary_shutter_open'
handler: 2
EPICS_is_running: 1
Methods, Events, Superclasses
Please select the probe beam as the light source. Hit any key to continue.
??? Error using ==> textscan
First input can not be empty.
Error in ==> HS_Camera>HS_Camera.get_exposure_time at 942
ccet = textscan(ccet,'%f %s');
-----------------
Added the following lines to HWS.db
record(ai, "C4:TCS-HWSX_PSC_PRISM")
record(ai, "C4:TCS-HWSX_PSC_ALPHA")
record(ai, "C4:TCS-HWSX_PSC_PHI")
record(ai, "C4:TCS-HWSX_PSC_CYLINDRICAL_PO")
record(ai, "C4:TCS-HWSX_PSC_SPHERICAL_POWE")
record(ai, "C4:TCS-HWSX_PSC_COMA")
record(ai, "C4:TCS-HWSX_PSC_BETA")
record(ai, "C4:TCS-HWSX_PSC_SPHERICAL_ABER")
record(ai, "C4:TCS-HWSX_SSC_PRISM")
record(ai, "C4:TCS-HWSX_SSC_ALPHA")
record(ai, "C4:TCS-HWSX_SSC_PHI")
record(ai, "C4:TCS-HWSX_SSC_CYLINDRICAL_PO")
record(ai, "C4:TCS-HWSX_SSC_SPHERICAL_POWE")
record(ai, "C4:TCS-HWSX_SSC_COMA")
record(ai, "C4:TCS-HWSX_SSC_BETA")
record(ai, "C4:TCS-HWSX_SSC_SPHERICAL_ABER")
- restarting IOC with C4:TCS-HWSX channels
-------------
-time to add these to the frames
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Tue Mar 1 10:47:18 2011 |
Aidan | Misc | Hartmann sensor | Electron to Counts conversion efficiency |
Using some of the old data from James (attached below), I calculated the CCD conversion efficiency (CE) from electrons to bits (Counts).
Number of electrons(Ne) = QE*Number of Photons(Np)
noiseE = sqrt(Ne);
Number of Counts (NCo)= CE*Ne
Noise in Counts (noiseCo)= CE*sqrt(Ne)
noiseCo = sqrt(CE * NCo)
log(CE) = 2*noiseCo - NCo
Therefore CE = 10.0^(2*noiseCo - NCo)
From James's data on the intensity noise in the CCD, CE = 0.0269
Quote: |
Using this function, I did the same analysis of the upper-left 200x200 pixels over all 200 images:
(data from 200 images, over the upper-left 200x200 pixels)
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117
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Tue Mar 1 11:19:34 2011 |
Aidan | Things to Buy | Delivery Note | MFF001 flipper mirror has arrived |
The Thorlabs MFF001 flipper mirror recommended by Bram has arrived. The delivery note is attached. |
Attachment 1: Flipper_mirror_delivery_notice.pdf
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118
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Tue Mar 1 11:21:37 2011 |
Aidan | Things to Buy | Delivery Note | More Bosch framing parts - angle connectors |
Another box of Bosch framing parts arrived today. The delivery note is attached. |
Attachment 1: Packing_List_04.pdf
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Tue Mar 1 17:05:45 2011 |
Aidan | Electronics | Hartmann sensor | Dalsa 1M60 current draw |
Steve and I measured the current drawn by the Dalsa 1M60 by connecting it to the BK Precision 1735 lab power supply that display current and voltage supplied. We tried the camera at a variety of different voltages. The results are presented below:
Voltage Current(t<5s) Current(5s<t<10s) Current(t>10s)
12.7V 0.6A 0.8A 1.11A
15.0V 0.55A 0.69A 0.91A
18.0V 0.41A 0.57A 0.75A
20.0V 0.42A 0.52A 0.67A
Additionally, we tried running the other camera with the lab power supply. I varied the exposure mode and exposure time and checked the current drawn. The supplied voltage was 18.0V.
Exposure Mode 4: current = 0.67A
Exposure Mode 2: 58Hz, exposure time = 16 ms, current = 0.70A
Exposure Mode 2: 58Hz, exposure time = 100 us, current = 0.72A
Exposure Mode 2: 1Hz, exposure time = 998 ms, current = 0.68A
Exposure Mode 2: 1Hz, exposure time = 16 us, gm 0, current = 0.69A
Exposure Mode 2: 1Hz, exposure time = 16 us, gm 2, current = 0.69A
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