| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
1269
|
Wed Jul 31 00:31:39 2013 |
tara | Notes | optic | coating optimization for AlGaAs | The codes for optimizing Thermo-optic noise
in coatings are up on svn.
I adopt some codes that have been |
|
|
1274
|
Thu Aug 1 21:19:57 2013 |
tara | DailyProgress | BEAT | searching for beat | I locked both cavities and trying to search
for the beat signal, I have not succeeded
yet. |
|
|
1275
|
Fri Aug 2 12:18:16 2013 |
tara | DailyProgress | BEAT | searching for beat | Found the beat @ 116 MHz. RCAV SLOW =5.762V,
ACAV SLOW = 1.209 V. |
|
|
1276
|
Fri Aug 2 12:38:41 2013 |
tara | DailyProgress | fiber optic | insulating foam | I turned off the hepa fans over the table
over the night. I came back this morning
and the temperature (measured on the vacuum |
|
|
1290
|
Fri Aug 9 16:00:14 2013 |
tara | Notes | NoiseBudget | noise hunting | I measured the slope of the error signal
for ACAV path to be 200 kHz/V. This will |
|
|
1291
|
Fri Aug 9 17:58:01 2013 |
tara | Notes | optic | coating optimization for AlGaAs | Better TO optimized coatings calculation
is done. Now the Transmission, phase reflection,
and TO noise are optimized. |
|
|
1293
|
Sat Aug 10 00:49:20 2013 |
tara | Notes | NoiseBudget | Thermo-refractive noise in substrate | I wrote a code to calculate thermo-refractive
noise in a finite-sized cylindrical substrate
as given in Heinert etal 2011. The noise |
|
|
1298
|
Tue Aug 13 21:45:51 2013 |
tara | DailyProgress | NoiseBudget | Transfer Functions (RIN to Frequency noise via photothermal) | I rechecked the TF between power fluctuation
and frequency noise in beat measurement that
I did last year. The estimated result agrees |
|
|
1300
|
Fri Aug 16 04:35:58 2013 |
tara | DailyProgress | NoiseBudget | Transfer Functions (RIN to Frequency noise via photothermal) | I estimated the requirement for laser RIN
for AlGaAs coatings. The result is a factor
of 5 more stringent from what we need for |
|
|
1305
|
Fri Aug 16 22:05:27 2013 |
tara | DailyProgress | BEAT | noise hunting | Noise hunting is in progress, I checked
the error noise from ACAV and RCAV loops
and compared them to the beat. The beat is |
|
|
1307
|
Tue Aug 20 20:10:01 2013 |
tara | DailyProgress | BEAT | noise hunting | Noise hunting is in progress. Today I identified
that scattered light from the window is one
of the problem. |
|
|
1309
|
Thu Aug 22 00:29:32 2013 |
tara | DailyProgress | NoiseBudget | installed EOAM | I installed an electro-optic amplitude
modulator (EOAM) in RCAV path. Better optimization
will be needed to reduce extra noise. |
|
|
1310
|
Thu Aug 22 13:36:19 2013 |
tara | DailyProgress | NoiseBudget | Transfer Functions (RIN to Frequency noise via photothermal) | I went through all the code with
Evan and found another mistake. This time
the code should be correct, and the result |
|
|
1311
|
Thu Aug 22 20:31:28 2013 |
tara | DailyProgress | NoiseBudget | installed EOAM | The bump at 2kHz in the beat signal that
I saw before was also from RFAM. By adjusting
the 1/2 waveplate in front of the sideband |
|
|
1313
|
Sat Aug 24 15:42:54 2013 |
tara | DailyProgress | Vacuum | pumping down the chamber | I closed the chamber. The turbo pump is
on and pumping down.
I realigned the beams so the |
|
|
1315
|
Tue Aug 27 16:11:26 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | Since the optimized layer structure is
designed, I'm checking how the coatings properties
change with error in layer thickness. |
8x |
|
1317
|
Wed Aug 28 20:19:44 2013 |
tara | Notes | EOM | EOM driver: modification | We modified the EOM driver, so that the
resonant frequency is now~ 14.75MHz. The
full test will be done later. |
|
|
1318
|
Wed Aug 28 21:21:38 2013 |
tara | Notes | optic | GWINC for TO calculation: recap | Here is a summary for how I verify the
codes for TO calculation.
So far, we have been using a set |
|
|
1319
|
Thu Aug 29 13:25:49 2013 |
tara | DailyProgress | Vacuum | pumping down the chamber | The turbo pump is removed, and the ion
pump is on. The initial value is ~7mA.
I removed the turbo pump and turn |
|
|
1320
|
Sun Sep 1 18:38:37 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | I updated the optimization and error analysis.
The error in optimized structure is comparable
to that of a standard quarter wave length |
7x |
|
1321
|
Mon Sep 2 03:38:27 2013 |
tara | DailyProgress | NoiseBudget | beat | It's a quiet night, so I went down the
lab to measure the beat signal. We are getting
close. I think I have to review my noise |
|
|
1322
|
Mon Sep 2 18:31:46 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | Coating optimization and error analysis
are updated, see PSL:1320. |
|
|
1327
|
Sat Sep 7 04:29:32 2013 |
tara | DailyProgress | NoiseBudget | beat | Short note from tonight measurement:
1) scattered bump from dc to 100Hz
is mostly from seismic. It is worse during |
|
|
1329
|
Mon Sep 9 02:27:46 2013 |
tara | DailyProgress | NoiseBudget | RIN induced TO noise in beat | The measured RIN is measured and converted
to frequency noise via photo thermal effect
then compared to beat. The effect seems to |
6x |
|
1331
|
Mon Sep 9 21:19:24 2013 |
tara | DailyProgress | NoiseBudget | RIN induced TO noise in beat | I'm trying to understand the measured RIN
in the setup. The evidence suggests that
the measured RIN in 100Hz- 6kHz, is real |
|
|
1332
|
Tue Sep 10 04:53:34 2013 |
tara | DailyProgress | NoiseBudget | RIN induced TO noise in beat | The cause of the peaks around 1kHz in RIN
is solved, PMC is the reason. After damping
it, the peaks disappears. |
|
|
1338
|
Tue Sep 17 19:43:45 2013 |
tara | Summary | NoiseBudget | Coating Thermal Noise Calculator |
|
|
|
1340
|
Wed Sep 18 21:55:11 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis |
Optimized coatings structure.
|
|
|
1342
|
Thu Sep 19 14:55:11 2013 |
tara | Summary | NoiseBudget | Coating Thermal Noise Calculator |
|
|
|
1343
|
Thu Sep 19 18:09:18 2013 |
tara | Summary | NoiseBudget | Coating Thermal Noise Calculator |
|
|
|
1344
|
Thu Sep 19 20:38:17 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | Details for AlGaAs coatings order
Coating
structure can be found in |
|
|
1345
|
Fri Sep 20 19:26:45 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | I'm using Matt's code to do error analysis
for AlGaAs coatings. This time I vary materials'
parameters and compare the thermo optic noise, |
|
|
1351
|
Mon Sep 23 18:50:05 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis |
|
|
|
1356
|
Thu Sep 26 23:25:40 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | I'm trying to find another optimization
that is less sensitive to change in nH and
nL. Here is a few thought and a few examples. |
8x |
|
1359
|
Thu Oct 3 10:34:32 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | The new optimization is less sensitive
to the values of refractive indices, but
the overall error will not change much if |
|
|
1360
|
Mon Oct 7 19:53:53 2013 |
tara | DailyProgress | Seismic | new table legs installed | New legs were installed. The table
is floated. The cables for signals/ power
supplies will be reconnected later |
|
|
1363
|
Thu Oct 10 01:59:24 2013 |
tara | Notes | optic | coating optimization for AlGaAs:error analysis | I recalculated the coatings properties,
with the values of nH and nL to be 3.48 and
2.977. Note about each optimization is included |
|
|
1365
|
Fri Oct 11 15:23:54 2013 |
tara | Notes | optic | coating optimization for AlGaAs:electric field in coating layer | Electric field in coating layer is calculated.
This will be used in loss calculation in
AlGaAs coatings. |
6x |
|
1367
|
Mon Oct 14 21:02:00 2013 |
tara | Notes | optic | coating optimization for AlGaAs:variation in x | I checked the dependent of coatings properties
with the uncertainty in x (amount of Al in
Al_x Ga_(1-x) As). |
|
|
1370
|
Tue Oct 22 04:34:12 2013 |
tara | DailyProgress | Seismic | new table legs installed | After installing the table legs, I have
been trying to measure the beat. However,
there is an unknown scattered light noise |
|
|
1374
|
Sun Oct 27 20:12:25 2013 |
tara | Notes | optic | photothermal noise in AlGaAs | I revised the calculation for photo-thermal
noise in AlGaAs coatings, the photo thermal
noise should not be a limiting source. |
|
|
1376
|
Wed Oct 30 01:56:38 2013 |
tara | DailyProgress | optic | table work | I'm optimizing the setup, and clearing
the table a little bit.
Self homodyne setup in |
|
|
1377
|
Thu Oct 31 00:02:17 2013 |
tara | DailyProgress | Electronics Equipment | TTFSS | Evan found that when common gain is changed,
DC offset also changes as well. I'm still
looking into the problem. |
|
|
1379
|
Fri Nov 1 00:22:40 2013 |
tara | DailyProgress | optic | more optimization | I'm putting EOAM back on ACAV path. The
setup is roughly optimized.
(14.75 MHz) EOM , EOAM, quarter waveplate |
|
|
1381
|
Tue Nov 5 01:11:15 2013 |
tara | DailyProgress | Electronics Equipment | TTFSS |
|
|
|
1383
|
Wed Nov 6 01:14:58 2013 |
tara | DailyProgress | Electronics Equipment | TTFSS | We made a mistake by choosing the input
power to the cavities to be 0.25 mW, so today
I turned them back to 1mW and measure the |
|
|
1384
|
Thu Nov 7 05:08:13 2013 |
tara | DailyProgress | NoiseBudget | photothermal noise in SiO2/Ta2O5 | I add the photo thermal noise effect in
the noise budget. With ISS, photothermal
noise should be sufficiently small. |
|
|
1385
|
Fri Nov 8 03:36:44 2013 |
tara | DailyProgress | optic | redo- PMC path | I'm re-arranging the optics in PMC path
a bit. The work is in progress, so ACAV path
is still down. |
|
|
1386
|
Mon Nov 11 19:37:13 2013 |
tara | DailyProgress | optic | redo- PMC path | PMC path is back, I aligned the polarization
of the input beam to the BB EOM for TTFSS.
The visibility of PMC is now ~ 80%. |
|
|
1387
|
Tue Nov 12 15:27:32 2013 |
tara | Notes | Documentation | thesis on ctn | I created an svn folder for my thesis on
CTN measurement.
It can be found here |
|