Differences between revisions 30 and 31

Arm Length Stabilization System

Wiki for ALS (Arm Length Stabilization; Auxiliary Lock System), a.k.a green lock system

ALS Configuration

To Do

optical layout of PR2/SR2 chambers, POP/POS table
select AOM and AOM driver
- DONE
fix green fiber specs, including how to do the laying
fiber collimators for green
green fiber after EOM/AOM or before EOM/AOM
- Not much difference from noise, cable length point of view.
- Alignment jitter noise from AOM will be less if fiber comes after AOM. So, let it so.
fiber for PLL beat or not
- DECIDED not to use fiber for PLL (March 5, 2018)
where to put frequency offset: PLL or arm length
more detailed noisebudget
initial alignment planning
comm/diff servo topology
- necessity of summing node for common mode servo (LIGO-D1300782)
  - first, try with digital switch and decide
lock acquisition scheme

Broadband PD for PLL Newport 818-BB-21A (1.2 GHz bandwidth)
Resonant PD for green PDH JGW-D1201280
AOM G&H 3080-125 (80MHz) and AOM driver G&H 1075FM-1 (1W, 5MHz BW). (ordered)
EOM: Qubig xxxxxx (ready)
- modulation frequencies are 32 MHz and 33 MHz JGW-T1605626
QPD for green beam pointing? (Use Oplev QPD?)
Picomotor mount? (ordered)

Fiber (under test at UToyama)
- probably with jacket, with endcap, without AR coating
- polarization maintaining
Fiber collimator (Tholabs PAF? Thorlabs triplet lens collimator?)

-  ⇤ ← Revision 30 as of 2018-03-12 10:44:09 → 
  Size: 4525
  Editor: YutaMichimura
  Comment:
+   ← Revision 31 as of 2018-03-12 10:45:59 → ⇥
  Size: 4589
  Editor: YutaMichimura
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
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+  * DONE
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+  * DECIDED not to use fiber for PLL (March 5, 2018)