Attachment 'green_lock_draft.txt'
Download 1 green lock ÉÖ·é|[gi´Äj
2
3 \subsection{Green Lock}
4 % aso> S: C¤AVäA·ì
5 %-----------------------------------------------------------
6 % Nagano Ä (1064nm Optical Comb PLL) É¢ÄÍ
7 %@green laser Ì±Ì subsection ÉÍüêÈ¢±ÆɵܷB
8 %@¶³ñÆ·ì³ñÌÔÅbµÁĺ³¢B
9 %-----------------------------------------------------------
10
11 \subsubsection{Green lock ÌKv«}
12 @Deterministic lock À»Ì½ßAå±ÂvÌbNV[PXÆÖíèÈAr¤Uíðñ¤UóÔÉÛ±ÆðÚIÆ·éB
13 ܽAgreen laser É뵀 finesse = 100 öx̤UíÝvð·é±ÆÉæèAbNEANCWVÌïÕxðy¸Å«é±ÆàdvÈðÅ éB
14
15 %-----------------------------------------------------------
16 \subsubsection{Green laser Éηévl}
17
18 Frequency stability:
19 RMS:
20 @@@ügÀèxª«èÈ¢ÆAmain beam ðgÁ½ZT[Ö̧äØÖª¢ï
21 ÆÈéÌÅA main beam Éηé¤U̼lSÌ 1/10 öx
22 50 kHz / Finesse /10 = 50 kHz /1450 /10 = 3.5 Hz RMS
23 (500 nm / Finesse /10 = 500 nm /1450 /10 = 34 pm RMS)
24 ½¾µ±êÍ main beam Ìhç¬ÆÌ·ªÉηévlB
25 (Central part Í main beam ÌügðîÉ mass feedback Å éÌÅAgreen laser
26 ÆÌ·ªÌݪâèÅ éB)
27
28 @Frequency range:
29 offset lock ̽ßÌ shift ÊÍ 200 Hz öxB
30
31 mass ÖÌ feedback ðOñÆ·éªA^pã freq. feedback Åà lock Â\Æ·é
32 ÉÍAAAA¾Ì RMS Uª 1.3 um ÈÌÅA¤Uí·Ìhç¬Í 1.3 um * sqrt(2) = 1.8 umB
33 @3{Ì]TðÝéÆ 1.8 um * 3 = 5.4 um = 11 * FSR
34 @FSR Ì11 {Í 550 kHz B
35
36 @Laser Power:
37 PD ÖÌüËõÊð 1mW ÆÝèB
38 ´ÁèÆAüËõwnÅ 50% lossAoËõwnÅà 50% loss ƼèµÄ
39 10mW / 25% = 4 mW ÈãKvÆ·éB
40
41 @(Modulation freq.):
42 ê main beam Égp·é f1, f2 ÆÍÊÌügðIè·é±ÆÉ·éB
43 TAMA dlð¥PµÄ 15 MHzB
44
45
46 %-----------------------------------------------------------
47 \subsubsection{Green laser Éηé¤UíÝv}
48 »óÅÍA1064 nm Éηé½Ë¦ªÜÁÄȢ̎wÌÝvÍs\B
49
50 Advanced LIGO ÌÝv
51 R1 =98.7-98.5 %, R2 =0.999995 --> finesse = 416-480 for 1064 nm
52 R1 (end mirror) = 95%, R2 (input mirror) > 99.9% --> finesse = 120 for 532 nm
53
54 Advanced LIGO spec.
55 End Test Mass: E0900068-v2
56 Transmission at 1064 nm
57 5 ppm +/- 1 ppm
58 Transmission at 532 nm
59 0.03 - 0.15, goal of 0.05
60
61 Input Test Mass: E0900041-v4
62 Transmission at 1064 nm
63 0.013 - 0.015 requirement
64 Transmission at 532 nm
65 <0.01, goal <0.001
66
67 R1 = 98.7-98.5 %, R2=0.999995 --> finesse = 416-480 for 1064 nm
68
69 ½Ë¦ÌeÍÍÆtBlX
70
71 %-----------------------------------------------------------
72 \subsubsection{Lock sequence on green laser lock}
73
74 1) r¤Uíð green laser g·ðîÉ mass Ö feedback µÄA
75 ¤UóÔÉbNB
76 \ß green laser Ìügð¸çµÄAmain beam ÉεÄ
77 1-2 nm offset (Ref.1) lock ·éæ¤ÉÝè·éB
78
79 FSR = c /2 /L = 50 kHz
80 50 kHz * (2 nm /532 nm) = 200 Hz
81
82 2) main beam ð¸õµ½óÔ (5W üË) ÅAcentral part ðbNB
83 @@ ±Ì_ÅAr¤UíÍ green laser Éæè
84 main beam É뵀 offset lock óÔÅ éB
85
86 3) QÂ̤UíÉεA¯úµÄ offset ð¸ç·B
87 @@@offset ÍAmain beam Éηé¤U̼l¼ªÚÀB
88 532 nm /Finesse /2 = 532 nm /1450 /2 = 0.18 nm
89
90 4) »ÌãAmain beam Éæé L+ MÖ§äØÖµA
91 ®SÉ offset ð[É·éB
92
93 5) ÅãÉAmain beam üËõÊðõ·éB
94
95 Ref.1:
96 http://gw.icrr.u-tokyo.ac.jp:8888/DocDB/0000/G0900037/001/20090723_offsetlock.pdf
97 %------------------------------------------------------------
98
99 %------------------------------------------------------------
100 \subsubsection{}
101 shot noise Í 1.5e-17 m/sqrt(Hz)
102 df = 1.5e-17 m/sqrt(Hz) / 3000 m * 600 THz = 3e-6 Hz/sqrt(Hz)
103 %------------------------------------------------------------
104
105 [5] Long-Sheng Ma, Peter Jungner, Jun Ye, and John L. Hall. Delivering the same optical frequency at two places: accurate cancellation of phase noise introduced by an optical fiber or other time-varying path. Optics Letters, 19:1777, 1994.
106
107 [6] Jun Ye et al. Delivery of high-stability optical and microwave frequency standards over an optical fiber network. J. Opt. Soc. Am. B, 20:1459, 2003.
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