|
Size: 1208
Comment:
|
Size: 1769
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 1: | Line 1: |
| = Green Laser Injection for Arm Pre-Lock = | <<Anchor(TOP)>> = Arm Length Stabilization using green laser beams = |
| Line 3: | Line 4: |
| We plan to install green lasers, which are phase locked to the PSL laser, at each end station to pre-lock the arm cavities before the lock acquisition. | . attachment:god_of_green.png |
| Line 5: | Line 7: |
| == Basic Concept == | |
| Line 7: | Line 8: |
| == Noise Requirement == I'd say the arm cavity length should not change more than 1/100 of the resonance width in the time scale of 10sec.[[BR]] For this to be fulfilled, the RMS fluctuation of the cavity length must be suppressed below 1e-11m level.[[BR]] Does this make sense ? |
* [[Upgrade 09/Purchase List/Green Locking|Purchase list]] |
| Line 12: | Line 10: |
| === Noise Sources === ==== PLL phase noise ==== ==== Phase noise from the cavity common mode motion ==== When the cavity is locked to the green laser, the differential motion of the two mirrors will be suppressed by the servo. However, the common motion of the cavity mirrors will not be suppressed. This common motion will show up as phase noises of the lasers. The time derivative of phase noise is equivalent to frequency noise. The equivalent displacement noise seen by the cavity is dL=(w*x*L)/c, where w is the angular frequency, x is the displacement noise spectrum of the common motion, L is the length of the cavity and c is the speed of light (see [attachment:PhaseNoise.pdf|this]). |
* Description of the optical / servo configuration [https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=6888 LIGO DCC] * Servo modeling (!SimLink) [https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/upgrade08/Green_Locking/Servo_modeling/ 40mSVN] . <<ImageLink(green_vertex_preliminary_design.png,Upgrade 09/GreenLock/Preliminary design for the vertex,height=200)>> <<ImageLink(green_ETM_preliminary_design.png,Upgrade 09/GreenLock/Preliminary design for the end,height=200)>> * Optical Layout ([attachment:green_optics.png Table]/ In-vac) * [[Upgrade 09/GreenLock/end table|ETM / end table]] <<ImageLink(endtable.jpg,Upgrade 09/GreenLock/end_table)>> * [[Upgrade 09/Optical Layout#wedge|ITM wedge effect]] * [[Upgrade 09/Optical Layout|Periscopes for beam steering from PR3/SR3 transmissions to the PSL viewport]] * Mode matching ([attachment:modematch_END.png mode matching at end table]) * Green generation . [attachment:manual_oven.pdf manual for the covesion oven] * B) [[Upgrade 09/GreenLock/Electronics|Electronics]] . B) [[Upgrade 09/GreenLock/Control Information|jump to Control Information]] . {i} [[Upgrade 09/GreenLock/Noise Requirement|jump to Noise Requirement]] . {i} aLIGO ALS wiki http://ilog.ligo-wa.caltech.edu:7285/advligo/Arm_Length_Stabilisation . {i} Description of the optical / servo configuration [https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=6888 LIGO DCC] . {i} Servo modeling (!SimLink) [https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/upgrade08/Green_Locking/Servo_modeling/ 40mSVN] |
Arm Length Stabilization using green laser beams
- attachment:god_of_green.png
Description of the optical / servo configuration [https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=6888 LIGO DCC]
Servo modeling (SimLink) [https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/upgrade08/Green_Locking/Servo_modeling/ 40mSVN]
- Optical Layout ([attachment:green_optics.png Table]/ In-vac)
- Mode matching ([attachment:modematch_END.png mode matching at end table])
- Green generation
- [attachment:manual_oven.pdf manual for the covesion oven]
aLIGO ALS wiki http://ilog.ligo-wa.caltech.edu:7285/advligo/Arm_Length_Stabilisation - Description of the optical / servo configuration [https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=6888 LIGO DCC]
- Servo modeling (SimLink) [https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/upgrade08/Green_Locking/Servo_modeling/ 40mSVN]
