Mode matching optical system for ALS at the side of PR2 and SR2
Last modified : 2017/09/04
Under investigation : Which is the better of the 2 lens or 3 lens
Contents
Target beam parameter
For Y-arm
Mirror |
q-parameter |
waist radius [mm] |
beam radius [mm] |
|||
qx |
qy |
W0x |
W0y |
Wx |
Wy |
|
SR2 (AR-surface) |
1.141658 + 0.026444i |
1.145729 + 0.026587i |
0.066919 |
0.067099 |
2.889797 |
2.892313 |
SR2 (HR-surface) |
1.485931 + 0.040023i |
1.488242 + 0.040171i |
0.082325 |
0.082478 |
3.057628 |
3.056716 |
SR3 (Input) |
12.597431 + 0.040023i |
12.599742 + 0.040171i |
0.082325 |
0.082478 |
25.912697 |
25.869453 |
BS (HR-surface) |
-1020.981427 + 292.656219i |
-1017.458984 + 291.640312i |
7.039791 |
7.027562 |
25.548554 |
25.504674 |
ITMY (HR-surface) |
-1500 + 774.596669i |
11.452985 |
24.961202 |
|||
ETMY (HR-surface) |
1500 + 774.596669i |
11.452985 |
24.961202 |
|||
For X-arm
Mirror |
q-parameter |
waist radius [mm] |
beam radius [mm] |
|||
qx |
qy |
W0x |
W0y |
Wx |
Wy |
|
PR2 (AR-surface) |
1.180362 + 0.026317i |
1.182840 + 0.026422i |
0.066757 |
0.066891 |
2.994930 |
2.995218 |
PR2 (HR-surface) |
1.530937 + 0.039779i |
1.533251 + 0.039928i |
0.082075 |
0.082228 |
3.159778 |
3.158651 |
PR3 (Input) |
12.597037 + 0.039779i |
12.599351 + 0.039928i |
0.082075 |
0.082228 |
25.991009 |
25.947268 |
BS (HR-surface) |
-1024.352551 + 292.664734i |
-1020.788880 + 291.640312i |
7.039893 |
7.027562 |
25.626199 |
25.581817 |
ITMX (HR-surface) |
-1500 + 774.596669i |
11.452985 |
24.961202 |
|||
ETMX (HR-surface) |
1500 + 774.596669i |
11.452985 |
24.961202 |
|||
Mode matching optical system
Conditions |
- The waist radius of the transmitted beam from the fiber = 350um (measured)
- Optical path length from AR-surface of SR2/PR2 to the optical table ~ 2m
- Assume CVI lenses
Back of SR2
Pattern A (2 lenses)
Mirror |
q-parameter |
Waist radius [mm] |
Beam radius [mm] |
|||
qx |
qy |
W0x |
W0y |
Wx |
Wy |
|
Fiber coupler |
0 + 0.723393i |
0.350 |
0.350 |
|||
L1 (Input) |
0.220 + 0.723393i |
0.350 |
0.365828 |
|||
L1 (Output) |
-0.108344 + 0.015935i |
0.051947 |
0.356989 |
|||
L2 (Input) |
0.759858 + 0.016086i |
0.051947 |
2.199920 |
|||
L2 (Output) |
-0.865307 + 0.026488i |
0.066974 |
2.188928 |
|||
SR2 (AR) |
1.143693 + 0.026488i |
0.066974 |
2.892571 |
|||
SR2 (HR) |
1.489013 + 0.040119i |
1.485169 + 0.039991i |
0.082425 |
0.082292 |
3.060270 |
3.057282 |
ITMy (HR) |
-1463.753784 + 729.531387i |
-1538.350364 + 822.405327i |
11.114831 |
11.801137 |
24.917463 |
25.031092 |
ETMy (HR) |
1536.246216 + 729.531387i |
1461.649636 + 822.405327i |
11.114831 |
11.801137 |
25.910643 |
24.066063 |
Pattern B (3 lenses)
Mirror |
q-parameter |
Waist radius [mm] |
Beam radius [mm] |
|||
qx |
qy |
W0x |
W0y |
Wx |
Wy |
|
Fiber coupler |
0 + 0.723393i |
0.350 |
0.350 |
|||
L1 (Input) |
0.089 + 0.723393i |
0.350 |
0.352639 |
|||
L1 (Output) |
0.108858 + 0.016086i |
0.052192 |
0.357035 |
|||
L2 (Input) |
0.759858 + 0.016086i |
0.052192 |
2.465986 |
|||
L2 (Output) |
0.434746 + 35.905184i |
2.465809 |
2.465990 |
|||
L3 (Input) |
1.019746 + 35.905184i |
2.465809 |
2.466803 |
|||
L3 (Output) |
-0.973312 + 0.026619i |
0.067139 |
2.455838 |
|||
SR2 (AR) |
1.143688 + 0.026619i |
0.067139 |
2.885427 |
|||
SR2 (HR) |
1.489002 + 0.040318i |
1.485159 + 0.040189i |
0.082629 |
0.082496 |
3.052712 |
3.049731 |
ITMy (HR) |
-1461.017819 + 731.892574i |
-1535.118889 + 824.885592i |
11.132804 |
11.818919 |
24.856063 |
24.969411 |
ETMy (HR) |
1538.982181 + 731.892574i |
1464.881111 + 824.885592i |
11.132804 |
11.818919 |
25.921818 |
24.087634 |
Back of PR2
Lens displacement
For Y-arm
Pattern A (2 lenses)
GreenModeMatch_2lens_170904.pdf
Pattern B (3 lenses)
GreenModeMatch_3lens_170904.pdf