Mode matching optical system of Green Lock System
Contents
Target beam parameter
Y-axis
Mirror |
q-parameter |
waist radius [mm] |
beam radius [mm] |
|||
qx |
qy |
W0x |
W0y |
Wx |
Wy |
|
SR2 (AR-surface) |
1.141436 + 0.026444i |
1.145506 + 0.026587i |
0.066919 |
0.067099 |
2.889234 |
2.891750 |
SR2 (HR-surface) |
1.485931 + 0.040023i |
1.488242 + 0.040171i |
0.082325 |
0.082478 |
3.057627 |
3.056715 |
SR3 (Input) |
12.597431 + 0.040024i |
12.599742 + 0.040171i |
0.082325 |
0.082478 |
25.912690 |
25.869443 |
BS (HR-surface) |
-1017.395806 + 291.640196i |
-1017.396204 + 291.640312i |
7.027560 |
7.027562 |
25.503215 |
25.503220 |
ITMY (HR-surface) |
-1500 + 774.596669i |
11.452985 |
24.961202 |
|||
ETMY (HR-surface) |
1500 + 774.596669i |
11.452985 |
24.961202 |
|||
X-axis
Mirror |
q-parameter |
waist radius [mm] |
beam radius [mm] |
|||
qx |
qy |
W0x |
W0y |
Wx |
Wy |
|
PR2 (AR-surface) |
1.179513 + 0.026317i |
1.181989 + 0.026422i |
0.066757 |
0.066891 |
2.992774 |
2.993064 |
PR2 (HR-surface) |
1.530937 + 0.039779i |
1.533251 + 0.039928i |
0.082075 |
0.082228 |
3.159777 |
3.158650 |
PR3 (Input) |
12.597037 + 0.039779i |
12.599351 + 0.039928i |
0.082075 |
0.082228 |
25.991002 |
25.947259 |
BS (HR-surface) |
-1024.352272 + 292.664734i |
-1020.788469 + 291.640312i |
7.039893 |
7.027562 |
25.626193 |
25.581808 |
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
・ Waist radius of the beam from the fiber coupler = 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)
Pattern B (3 lenses)
Simulation of beam parameters using above optical system with FINESSE
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) |
0.095 + 0.723393i |
0.350 |
0.353005 |
|||
L1 (Output) |
-0.108744 + 0.016016i |
0.520787 |
0.357411 |
|||
L2 (Input) |
0.759744 + 0.016016i |
0.520787 |
2.470960 |
|||
L2 (Output) |
-0.699938 + 36.041929i |
2.470500 |
2.470966 |
|||
L3 (Input) |
1.324938 + 36.041929i |
2.470500 |
2.472169 |
|||
L3 (Output) |
-0.973537 + 0.026516i |
0.670087 |
2.461182 |
|||
SR2 (AR) |
1.143463 + 0.026516i |
0.670087 |
2.890476 |
|||
ITMy (HR) |
-1463.290098 + 730.177686i |
-1537.778046 + 823.090006i |
11.119753 |
11.806048 |
24.904507 |
25.018072 |
ETMy (HR) |
1536.709902 + 730.177686i |
1462.221956 + 823.090006i |
11.119753 |
11.806048 |
25.909775 |
24.068022 |
Back of PR2
Beam radius from the fiber coupler to arm cavity
Y-axis
Pattern A (2 lenses)
Pattern B (3 lenses)
