ID |
Date |
Author |
Type |
Category |
Subject |
3514
|
Thu Sep 2 16:41:32 2010 |
steve | Configuration | SAFETY | laser is ON: safety glasses required! |
I hooked up interlock to the Innolight 2W 1064 nm in the enclosure. The manual shutter is closed on this unit.
SAFETY GLASSES REQUIRED ! |
3517
|
Thu Sep 2 21:22:31 2010 |
Sanjit, Koji | Configuration | Computers | rossa nvidia driver and dual monitor configuration |
Simple steps (but don't try these on a working computer without getting some experience on a spare one, you may find it difficult to restore the system if something goes wrong):
- download the appropriate driver from NVIDIA website for this computer
- we did: NVIDIA GeForce 310 64bit Linux, version: 256.53, release date 2010.08.31
- keep/move the driver in /root (use "sudo" or "su")
- reboot the computer in "single user" mode
- in the GRUB screen edit the boot command by pressing the appropriate key listed in the screen
- in the boot command-line put " single" in the end (no other change is normally needed), don't save
- press ENTER and the system will reboot to a root shell (# prompt)
- cd /root
- run the NVIDIA driver script
- exit the shell (ctrl-d), let the system reboot
- it should flash (mostly green) "nvidia" screen before starting X
- in case of problems run system-config-display and revert to vesa driver
- login as "root" and run "nvidia-settings" from command line or GUI menu to add/configure display
|
3518
|
Thu Sep 2 23:35:33 2010 |
rana | Configuration | Computers | rossa nvidia driver and dual monitor configuration |
Why are we running CentOS 4.8 instead of 5.5 ? What runs at LLO? What runs in Downs? |
3521
|
Fri Sep 3 11:23:16 2010 |
josephb | Configuration | Computers | rossa nvidia driver and dual monitor configuration |
At LLO the machines are running Centos 5.5. A quick login confirms this. Specifically the release is 2.6.18-194.3.1.el5.
Quote: |
Why are we running CentOS 4.8 instead of 5.5 ? What runs at LLO? What runs in Downs?
|
|
3524
|
Sun Sep 5 21:35:41 2010 |
rana | Configuration | Computers | rossa notes |
**** Deleted
apps/emacs
apps/linux64/firefoxold
apps/linux64/comsol (old v. 3.5)
* running up2date on rossa
* rossa needs to be able move windows between monitors: Xinerama?
* there are permissions problems: controls on rossa can't
make and delete directories made by 'controls' elsewhere.
Some sort of user# or group issue? |
3526
|
Mon Sep 6 10:08:10 2010 |
Alberto | Configuration | Computers | Netgear Network Switch fan broken. |
The Netgear Network Switch in the top shelf of Nodus' rack has a broken fan. It is the one interfaced to the Martian network.
The fan must have broken and it is has now started to produce a loud noise. It's like a truck was parked in the room with the engine running.
Also the other network switch, just below the Netgear, has one of its two fans broken. It is the one interfaced with the General Computer Side.
I tried to knock them to make the noise stop, but nothing happened.
We should consider trying to fix them. Although that would mean disconnecting all the computers. |
3531
|
Tue Sep 7 10:50:53 2010 |
josephb | Configuration | Computers | rossa notes |
The controls group is user id 500 by default on most new machines. Unfortunately, the user ID used across the already existing machines is 1001. One method of doing this switch is in this elog. You can also do the change of the controls ID by becoming root and using the graphical command system-config-users. This will let you change the user ID and group ID for controls to 1001. This graphical interface also lets you change the login shell.
Unfortunately, I had some minor difficulty and I ended up removing the old controls and creating a new controls account with the correct values and using tcsh. The .cshrc file has been recreated to source cshrc.40m. The controls account now has correct permissions, although some of the preferences such as background will need to be reset.
Quote: |
**** Deleted
apps/emacs
apps/linux64/firefoxold
apps/linux64/comsol (old v. 3.5)
* running up2date on rossa
* rossa needs to be able move windows between monitors: Xinerama?
* there are permissions problems: controls on rossa can't
make and delete directories made by 'controls' elsewhere.
Some sort of user# or group issue?
|
|
3533
|
Tue Sep 7 14:42:02 2010 |
Dmass | Configuration | elog | elog restarted |
elog crashed on an upload. restarted and it worked fine with the same file. |
3535
|
Tue Sep 7 15:57:07 2010 |
Alberto | Configuration | Computers | Nodus connection not working. Fixed |
[Joe, Alberto]
The Nodus connection to the Martian network stopped working after someone switched cables on the Netgear router. Apparently that router doesn't like to have the 23 and 24 ports connected at the same time.
Joe fixed the connection just freeing either the 23 or the 24 port. |
3537
|
Tue Sep 7 22:21:17 2010 |
Alberto | Configuration | Computers | elog restarted |
|
3538
|
Tue Sep 7 22:21:47 2010 |
Dmass | Configuration | elog | elog restarted |
Quote: |
elog crashed on an upload. restarted and it worked fine with the same file.
|
Again. Resubmitted an old entry with just text changes. Elog hung for 5 min +. |
3539
|
Tue Sep 7 23:17:45 2010 |
sanjit | Configuration | Computers | rossa notes |
Quote: |
* rossa needs to be able move windows between monitors: Xinerama?
|
Xinerama support has been enabled on rossa using nvidia-settings. |
3540
|
Tue Sep 7 23:34:15 2010 |
Kiwamu, Sanjit | Configuration | Computers | e-log |
e-log was repeatedly hanging and several attempts to start the daemon failed.
problem was solved after clearing the (firefox) browser cache, cookie, everything!!
|
3541
|
Tue Sep 7 23:49:08 2010 |
sanjit | Configuration | Computers | aldabella network configuration |
added name server 192.169.113.20 as the first entry in /etc/resolv.conf
changed the host IPs in /etc/hosts to 192.168.xxx.yyy
made:
127.0.0.1 localhost.localdomain localhost
::1 localhost6.localdomain6 localhos6
as the first two lines of /etc/hosts
/cvs/cds mounts
on ethernet, DNS look-up works without the explicit host definitions in /etc/hosts,
but those entries are needed for wifi only connection.
|
3555
|
Thu Sep 9 18:53:56 2010 |
Alberto | Configuration | Electronics | Busby Box, Rai's Box, SR554 in the RF cabinet |
I stored the Busby Box, the Rai's Box and the SR554 preamp in the RF cabinet down the Y arm. |
3556
|
Fri Sep 10 02:35:30 2010 |
rana, kiwamu, valera, tara | Configuration | PSL | update |
Over the last couple nights we got the beam into the FSS path and all the way to the IMC and out onto the AP table.
Tara and Valera have calculated a mode-matching solution for the reference cavity. It utilizes only a single lens between the AOM and the reference cavity. Valera and Steve will move the reference cavity into place in the morning.
We noticed that the layout was too tight on the end going into the MC and so we adjusted the angle of the final zig-zag. This will put the final mode-matching lens in between the final steering mirrors (which is generally undesirable) but the lens in this case is only f=400 mm. In addition, this lens may provide some more decoupling between the steering mirrors.
The whole layout has to be a little adjusted because of a calculation mistake I made in the mode-matching. I used only the nominal focal lengths from the CVI catalog and not the effective one. For the UV-grade fused silica lenses, the effective focal length is actually 20-30% longer. Today we measured that the "f=200 mm" lens we got is actually f = 238 mm. The BK7 lenses are much closer to the nominal.
We also replaced the Klinger mount ahead of the PMC with a Polanski style so that we could get the PMC REFL beam out without hitting the mount. Valera will continue to refine this section on the weekend.
Tomorrow, we will lock the MC using feedback only to the NPRO. The 0-150 V piezo driver is on the PSL table ready for action.
I also got a LCD video monitor from Frank and hooked it up on the PSL table. If we like this kind of thing, we can get many of them. They are pretty cheap. It would be handy to have 3-4 of them on the PSL and one on every of the ISC tables. They take the standard video for input and need +12V for power. Right now the one in there is looking at the PMC transmission.
The Omnigraffle layout as of tonight is attached. |
Attachment 1: 40mPSL.pdf
|
|
3557
|
Sat Sep 11 03:16:51 2010 |
rana | Configuration | Computers | rossa notes |
I wiped out the old CentOS install on rossa and installed CentOS 5.5 on there. The DVDs are on a spindle in the control room; there were 2 iso's, but I only needed the first to install most things.
It still needs to get all of the usual stuff (java, flash, nvidia) installed as well as setting up the .cshrc and the NFS mount of /cvs/cds. The userID and groupID are set to 1001 as before. Whoever
sees Sanjit first should steer him towards this elog entry.
|
3559
|
Sun Sep 12 22:36:03 2010 |
rana | Configuration | Computers | rossa notes |
I found Sanjit's instructions for doing the Nvidia settings too complicated and so I followed these instructions from Facebook:
http://www.facebook.com/notes/centos-howtos/installing-nvidia-display-drivers-on-centos-55/399295987425
After installations, the monitors were autodetected and the Xinerama effect is working. |
3563
|
Mon Sep 13 02:45:59 2010 |
rana | Configuration | DMF | seisBLRMS restarts |
I restarted the seisBLRMS DMF monitor by ssh'ing into mafalda and starting up a matlab session. I also have started a StripTool session on rossa by forwarding the process from op440m.
We need to get the modern EPICS installation onto these linux machines by copying what K. Thorne has done at LLO. |
3570
|
Mon Sep 13 22:51:07 2010 |
tara,valera | Configuration | PSL | beam scan for RCAV |
On Friday, Valera and I calculated the modematching for reference cavity from AOM.
We scan the beam profile where the spot should be.
The first beam waist in the AOM is 103 um, the lens (f= 183 mm, I'm not sure if I have the focal length right) is 280 mm away.
The data is attached. The first column is marking on the rail in inches,
the second column is distance from the lens, the third and fourth column are
vertical and horizontal spot radius in micron. Note that the beam is very elliptic because of the AOM. |
Attachment 1: 2010_09_10_w.mat
|
3586
|
Sun Sep 19 18:09:09 2010 |
rana | Configuration | Cameras | Blue IP Camera installed on the PSL table |

I installed the blue IP camera from ZoneNet onto the PSL table. It gets its power from the overhead socket and connects via Cat5 to the Netgear switch in the PSL/IO rack.
You can connect to it on the Martian network by connecting to http://192.168.113.201:3037. Your computer must have Java working in the browser to make that work.
So far, this works on rossa, but not the other machines. It will take someone with Joe/Kiwamu level linux savvy to fix the java on there. I also don't know how to fix the host tables, so someone please add this camera to the list and give it a name.
As you can see from the image, it is illuminating the PSL with IR LEDs. I've sent an email to the tech support to find out if we can disable the LEDs. |
3587
|
Sun Sep 19 18:52:52 2010 |
rana | Configuration | PSL | NPRO SLOW servo settings updated for Innolight NPRO |
Our new 2W Mephisto has a pretty zippy "SLOW" temperature input. Tuning the perl PID servo, I found that the best response came from setting
the "P" and "D" terms to zero. This is because the internal temperature stabilization servo has a fairly high UGF. In the attached
image you can see how the open loop step response looks (loop is open then the "KI" parameter is set to zero). The internal servo
really has too little damping. There is a 30% overshoot when it gets a temperature step. For this kind of servo Innolight would have done better
to back off on the gain until they got back some phase margin.
New SLOW parameters:
timestep = 1.9 s
KP = 0
KI = 0.035
KD = 0
|
Attachment 1: Untitled.png
|
|
3591
|
Mon Sep 20 17:10:10 2010 |
steve | Configuration | PSL | enclosure beam guides to IFO are installed |
The PSL out 2" OD beam guide tube was cut 1.5" shorter to 13.5"
The 10" OD 0.25" wall Al tube was replaced by a lighter, not anodized and thinner wall 0.094" tube of 15.5" lenght, that is 0.75" shorter.
The new position of the PSL table made these cuts necessary. |
3595
|
Wed Sep 22 22:22:12 2010 |
Koji | Configuration | Computers | Netgear Network Switch fan broken. |
Net switch mumbo-jumbo:
Although Rana is going to buy a replacement for the Netgear Switch for martian, I opened the lid of the Netgear as the fan already have stopped working.
Also the lid of the other network switch for GC (Black one) was opened as it has a broken fan and a noisy half-broken fan.
I have asked Steve to buy replacement fans. These would also be the replacement of the replacement.
During the work, it seemed that I accidentally toggled the power supply of linux1. It lead lengthy fsck of the storage.
This is why all of the machines which rely on linux1 got freezed. linux1 is back and the machines looked happy now.
If you find any machine disconnected from the network, please consult with me.
Quote: |
The Netgear Network Switch in the top shelf of Nodus' rack has a broken fan. It is the one interfaced to the Martian network.
The fan must have broken and it is has now started to produce a loud noise. It's like a truck was parked in the room with the engine running.
Also the other network switch, just below the Netgear, has one of its two fans broken. It is the one interfaced with the General Computer Side.
I tried to knock them to make the noise stop, but nothing happened.
We should consider trying to fix them. Although that would mean disconnecting all the computers.
|
|
3605
|
Fri Sep 24 16:31:35 2010 |
steve | Configuration | General | open frame- rack is moved |
The squeezing open frame rack was moved from the south side of the PSL enclosure to the north side of the SP table.
AC power breaker is PC-2 #1
|
Attachment 1: P1060881.JPG
|
|
3611
|
Mon Sep 27 08:59:50 2010 |
steve | Configuration | VAC | slow vent has started |
Blocked PSL output beam into IFO
Checked: HV at IOO & OMC are off, jam nuts in position,
Closed V1 and VM3, opened VV1 to N2 regulator
We are venting at 1 Torr/min rate |
3614
|
Tue Sep 28 00:07:45 2010 |
kiwamu | Configuration | VAC | Re: slow vent has started |
(Koji, Yuta, Kiwamu)

Now the pressure at P1 is 740 torr, which is close to the atmospheric pressure of 760 torr.
We changed the air cylinder twice in this evening, and the last cylinder ran out at about 23:00 pm.
We left it as it is. Steve is going to make a final touch for it tomorrow morning. |
3633
|
Fri Oct 1 11:33:15 2010 |
josephb, alex | Configuration | CDS | Changing gds code to the new working version |
Alex is installing the newly compiled gds code (compiled on Centos 5.5 on Rosalba) which does in fact include the ezca type tools.
At the moment we don't have a solaris compile, although that should be done at somepoint in the future. It means the gds tools (diaggui, foton, etc) won't work on op440m. On the bright side, this newer gds code has a foton that doesn't seem to crash all the time on Linux.
|
3634
|
Fri Oct 1 11:53:42 2010 |
josephb | Configuration | CDS | Added RCG simlink files to the 40m svn |
I've added a new directory in /opt/rtcds/caltech/c1/core called rts_simlink. This directory is now in the 40m svn. Unfortunately, the simlink files used to generate the front end c codes live in a directory controlled by the CDS svn. So I've copied the .mdl files from /opt/rtcds/caltech/c1/core/advLigoRTS/src/epics/simLink/ into this new directory and added them into the 40m svn. When making changes to the simlink files, please copy them to this new directory and check them in so we can a useful history of the models.
|
3643
|
Mon Oct 4 13:48:41 2010 |
Leo Singer | Configuration | Computers | Uninstalled gstreamer-devel and gstreamer-plugins-base-devel on rosalba |
I uninstalled gstreamer-devel and gst-plugins-base-devel on Rosalba. Here is the command I ran:
$ sudo yum remove gstreamer-devel gstreamer-plugins-base-devel
Actually, I had installed these myself a few days earlier, before I knew that I should be recording such changes in the elog. I'm sorry! |
3646
|
Tue Oct 5 09:26:04 2010 |
steve | Configuration | PEM | moved accelerometers |
Accelerometers xyz were moved from IOO-south/west corner to under PSL table. They were turned off for ~20 minutes.
Guralp was also moved eastward about 2 ft. It is not leveled.
This is part of the preparation to remove access connector. |
3650
|
Tue Oct 5 13:59:17 2010 |
Leo Singer | Configuration | Computers | Installed x264-devel on Allegra |
I installed the package x264-devel on allegra.martian. This package provides headers and libraries for the popular h264 video codec. I am going to use this in the GStreamer streaming media server on Allegra. |
3654
|
Tue Oct 5 17:39:21 2010 |
steve | Configuration | VAC | west access connector removed |
Kiwamu, Koji, Yutah, Rana, Jan and Steve
We removed the west access connector this afternoon. |
3676
|
Fri Oct 8 07:41:42 2010 |
steve | Configuration | SAFETY | 2W laser shutter is closed |
The 2 W Innolight shutter is closed and enclosure door removed. Beam path blocked. Do not change this condition. |
3677
|
Fri Oct 8 10:38:03 2010 |
steve | Configuration | SAFETY | 2W laser shutter is closed |
Quote: |
The 2 W Innolight shutter is closed and enclosure door removed. Beam path blocked. Do not change this condition.
|
The PSL output beam guide was upgraded from 2" to 8" OD . It is green ready. Shutter is open. |
Attachment 1: P1060905.JPG
|
|
Attachment 2: P1060910.JPG
|
|
3698
|
Tue Oct 12 16:35:17 2010 |
steve | Configuration | PSL | PSL output monitor in place |
Innolight PSL laser is set to @2.1A , ~1.6W output ! Please scan out when finished!
The output monitoring pick up window W2-LW-2-2050-UV-1064-45S is in place. IOO_ANG_OPD and IOO_POS_QPD roughly aligned.
The PMC alignment and/ or mode matching is bad. PMC reflected is 50%, throughput 600mW
Remember to block PSL output ! into IFO
|
3702
|
Tue Oct 12 23:45:55 2010 |
rana | Configuration | DAQ | NDS2 |
I installed the NDS2 Client onto the workstations today using the instructions that Zach put onto the Wiki with a couple of modifications.
1) Instead of the adding path stuff in Matlab, I added the LD_LIBRARY_PATH and MATLABPATH variables into the .cshrc as instructed by JZ's NDS2 Wiki.
2) I installed the stuff into the shared /cvs/cds/caltech/apps/linux64/ partition so that it works now on all the 64-bit CentOS 5.5 workstations.
To run it you do:
> kinit albert.einstein
> matlab -nodesktop -nosplash
> help NDS2_GetData
(set the server to the NDS2 server that you like - the example in the help is fine)
> result = NDS2_GetData({'L1:LSC-DARM_ERR'}, 957313530, 10, server);
> plot(result.data)
Now you can get any of the S6 data super fast.
(** Remember to run kdestroy as soon as you are finished so that no one else in the control room can use your personal credentials. **) |
Attachment 1: cerberus.jpg
|
|
3718
|
Thu Oct 14 13:09:01 2010 |
Leo Singer | Configuration | Computers | nds2-client-devel installed on rossa |
I installed nds2-client-devel on rossa using the following command:
$ sudo yum install nds2-client-devel |
3719
|
Thu Oct 14 13:15:14 2010 |
Leo Singer | Configuration | Computers | git installed on rossa |
I installed git on rossa using:
$ sudo yum install git |
3721
|
Thu Oct 14 14:52:52 2010 |
Leo Singer | Configuration | Computers | numpy, ipython, matplotlib, python-matplotlib installed on rossa |
I installed the following packages on rossa:
numpy, ipython, matplotlib, python-matplotlib |
3772
|
Sun Oct 24 19:23:41 2010 |
rana | Configuration | elog | ELOG 2.8.0 |
I stopped the ELOG and restarted us on 2.8.0.
To make sure nothing got lost, I killed the old process, copied over the logbooks/, themes/, and elogd.cfg to the new 2.8.0/ directory before starting the new Daemon.
I encountered the same Administrator bug as Joe had before. I delete all the old Admin passwords to bypass the issue.
To restart the ELOGD on NODUS, you now type '/cvs/cds/caltech/elog/start-elog.csh'.
I also added ELOG to the man pages in /usr/local/man/ on nodus by putting the *.1 files in man1/ and the *.8 files into man8/. |
3775
|
Mon Oct 25 02:23:47 2010 |
Koji | Configuration | elog | ELOG 2.8.0 |
When I push the reply button, the raw html shows up in the edit window and have to use HTML to write the entry.
Does this happen only to me???
Quote: | I stopped the ELOG and restarted us on 2.8.0.
To make sure nothing got lost, I killed the old process, copied over the logbooks/, themes/, and elogd.cfg to the new 2.8.0/ directory before starting the new Daemon.
I encountered the same Administrator bug as Joe had before. I delete all the old Admin passwords to bypass the issue.
To restart the ELOGD on NODUS, you now type '/cvs/cds/caltech/elog/start-elog.csh'.
I also added ELOG to the man pages in /usr/local/man/ on nodus by putting the *.1 files in man1/ and the *.8 files into man8/. |
|
3780
|
Mon Oct 25 23:59:37 2010 |
Koji | Configuration | elog | ELOG 2.8.0 -> ELOG 2.7.5 |
ELOG reverted to 2.7.5 due to editing difficulties
- /cvs/cds/caltech/elog/start-elog.csh reconfigured to launch 2.7.5
- /cvs/cds/caltech/elog/elog is linked to ./elog-2.7.5
- logbook dir of 2.8.0 was copied in the dir of 2.7.5. The old and obsolete 2.7.5 was discarded. |
3783
|
Tue Oct 26 07:02:05 2010 |
Alberto | Configuration | elog | ELOG 2.8.0 -> ELOG 2.7.5 |
Quote: |
ELOG reverted to 2.7.5 due to editing difficulties
- /cvs/cds/caltech/elog/start-elog.csh reconfigured to launch 2.7.5
- /cvs/cds/caltech/elog/elog is linked to ./elog-2.7.5
- logbook dir of 2.8.0 was copied in the dir of 2.7.5. The old and obsolete 2.7.5 was discarded.
|
I think I had the same problem when I switched to 2.75 from 2.65.
Then the problem was FCKeditor.
We should try the solution I put in the elog page of the wiki.
|
3784
|
Tue Oct 26 10:50:08 2010 |
Koji | Configuration | elog | ELOG 2.8.0 -> ELOG 2.7.5 -> ELOG 2.8.0 |
ELOG restarted with 2.8.0 again.
- moved elog-2.8.0/script dir to elog-2.8.0/script.orig
- copied elog-2.7.5/script to elog-2.8.0/script
- /cvs/cds/caltech/elog/start-elog.csh reconfigured to launch 2.8.0
- /cvs/cds/caltech/elog/elog is linked to ./elog-2.8.0
- logbooks on 25th and 26th were copied from 2.7.5 to 2.8.0.
|
3790
|
Tue Oct 26 22:57:37 2010 |
Jenne | Configuration | Computers | Why doesn't DTT work?!? |
DTT has only SUS and "X02" channels under C1 in the drop down channel selection menu. Basically, we can't measure any fast channels with DTT. I keep getting the error: "Unable to select testpoints." Sadface.
Similar things are true for DataViewer. The same limited number of fast channels, and no data found:
Server error 13: no data found
datasrv: DataWriteRealtime failed: daq_send: Illegal seek
Is this a framebuilder problem? Is this something that the CDS team has on the to-do list? |
3793
|
Wed Oct 27 10:53:03 2010 |
josephb | Configuration | Computers | Why doesn't DTT work?!? |
Test points for the SUS channels should be there. They have been working previously this week. Possibly break down points include awgtpman, mx_streams, and the fb itself. I'll look into that.
As far as other fast channels, there are no other fast front ends running than the suspensions ones we have. Until additional channels get connected to the front ends and the models updated, those are the channels we have available. However I am working on getting c1ioo up and running, and we can try connecting in some PEM channels today to the c1sus front end's 4th ADC.
Edit:
I tried starting a fresh instance of the frame builder, but when I brought the old copy down, it left a pair of zombie or dead mx_stream processes running on c1sus . Basically c1mcs and c1rms were still running, while c1x02 and c1sus came down. I tried to kill the processes but this caused the c1sus machine to crash. In the past I've killed left over mx_stream processes running after the frame builder has gone down, but I've never seen them crash the computer. I'm unsure why this happened since we haven't done any updates of the code, just updated models and daq configuration files.
Quote: |
DTT has only SUS and "X02" channels under C1 in the drop down channel selection menu. Basically, we can't measure any fast channels with DTT. I keep getting the error: "Unable to select testpoints." Sadface.
Similar things are true for DataViewer. The same limited number of fast channels, and no data found:
Server error 13: no data found
datasrv: DataWriteRealtime failed: daq_send: Illegal seek
Is this a framebuilder problem? Is this something that the CDS team has on the to-do list?
|
|
3835
|
Mon Nov 1 12:38:56 2010 |
Leo Singer | Configuration | Computers | python-sqlite installed on Allegra |
I installed the Python bindings for sqlite on Allegra using
$ sudo yum install python-sqlite python-sqlite2 |
3843
|
Tue Nov 2 00:17:01 2010 |
Suresh | Configuration | Locking | Temporary changes to the Video Mux |
Fiber coupling 1064 nm light at the end of X arm
This is 'work in progress'. The attempt is to bring a few milliwatts of the 1064 nm light from the NPRO at the end of the South(X) Arm to the PSL table through an single mode optical fiber. This would enable us to tune the two NPRO's to be less than 15 MHz apart by looking at their beat frequency before doubling. Because we have a 1GHz bandwidth PD at 1064 nm, while the photodiode for green has a BW of about 30MHz.
A PBS (P-type) cube has been introduced into the beam of the X arm NPRO (between the lamda/2 plate and the input lens of the doubling crystal). By rotating the face of the PBS slightly away from normal incidence, I have diverted away 1.5mW of the 1064 light for coupling into the fiber. The beam has shifted slightly because of this and the green beam from the south arm has to be realigned to reach the PSL table.
A single mode fiber (Thorlabs SM980-5.8-125), which was already laid half way, has been extended all the way to the PSL table. It runs along the South arm in the cable tray.
A pair of mirrors have been arranged in a zig-zag to steer the beam into a fiber coupler. There was some hope that this coupler had been aligned at some point in the past and that attaching a fiber might result in some transmission. But this is not the case and fiber coupler needs to be readjusted.
In order to see the light transmitted through the fiber, a camera has been set up on the PSL table. Its output has been routed into the 'Ref Cavity reflected' video signal. A video cable running from the ETMX to the Video-MUX used to be connected to the input channel 9 of the Video MUX. This has now been shifted to output channel 25 of the MUX and disconnected from the camera at the ETMX. The 'Ref Cav Refl.' video signal has been routed to the output channel 25. The camera looking at the fiber output can now be seen on a local monitor at the end of the X arm and on the video monitor in the control room.
With the fiber disconnected, the 1064 nm beam was steered into the fiber coupler and its transmission maximised by observing with an IR viewer. The fiber was then connected and then the transmission at the PSL table was sought. There was no transmission seen after a searching around this region for a few mins.
The plan is to purchase a Visual fault locator which would enable us to quickly get a rough alignment of the fiber coupler. A local vendor is listed as a distributor for this product from JDSU. Contact info:
DuVac Electronics (EDGE)
Tel: 626-796-3291
Email: jack@duvac.com
1759 E Colorado Blvd
Pasadena, CA 91106
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Tue Nov 2 16:49:02 2010 |
Jenne | Configuration | Cameras | Cabling on the PSL table |
Dear whomever setup the camera on the SW corner of the PSL table,
It would be handy if, even for temporary setups, all cables went underneath the white frame around the PSL table. As it is now, the cables are in the way of the door. The door is pretty much closed all the way, but if someone were to open other doors, the far door can easily be pushed all the way to the end of the track, thus squishing the cables. Squished cables are bad cables.
Thanks! |