Table 1
Six Strehl Ratios
Times
| 1
| 2
| 3
| 30
| 40
| 50
| 100
| 200
|
---|
STRA | 0.0675 | 0.0480 | 0.0409 | 0.0158 | 0.0145 | 0.0139 | 0.0137 | 0.0132 |
STRB | 0.0154 | 0.0109 | 0.0113 | 0.0089 | 0.0112 | 0.0116 | 0.0119 | 0.0116 |
STRC | 0.0188 | 0.0062 | 0.0139 | 0.0089 | 0.0112 | 0.0116 | 0.0121 | 0.0121 |
STRAA | 0.254 | 0.200 | 0.210 | 0.143 | 0.156 | 0.157 | 0.162 | 0.152 |
STRBB | 0.132 | 0.121 | 0.170 | 0.155 | 0.162 | 0.161 | 0.164 | 0.163 |
STRCC
| 0.225
| 0.197
| 0.192
| 0.155
| 0.162
| 0.161
| 0.164
| 0.164
|
Computational conditions: λ = 0.6328 µm;
L = 1 km; open loop;
C
n
2 = 10
-14
m
-2/3; phase-screen grids, 512 × 512; propagation
grids, 128 × 128, in center; ten phase screens.
Table 2
STRCC in Different Turbulent Media
C
n
2
(m-2/3)
| Times
| 1
| 2
| 3
| 30
| 40
| 50
| 100
| 200
|
---|
10-14.5
| OL | 0.596 | 0.551 | 0.492 | 0.496 | 0.520 | 0.514 | 0.495 | 0.502 |
AO | 0.881 | 0.883 | 0.876 | 0.859 | 0.858 | 0.858 | 0.856 | 0.854 |
10-14
| OL | 0.225 | 0.197 | 0.192 | 0.155 | 0.162 | 0.161 | 0.164 | 0.164 |
AO | 0.649 | 0.601 | 0.585 | 0.605 | 0.612 | 0.616 | 0.614 | 0.612 |
10-13.5
| OL | 0.0978 | 0.0634 | 0.0613 | 0.0536 | 0.0532 | 0.0523 | 0.0487 | 0.0490 |
AO
| 0.165
| 0.214
| 0.210
| 0.223
| 0.221
| 0.220
| 0.214
| 0.212
|
Computational conditions: 61-unit AO system; others, see
Table
1. OL, open loop.
Table 3
Effect of Grid Number of Propagation on Strehl Ratio
C
n
2
(m-2/3)
| 10-13.5
| 10-14
| 10-14.5
|
Grid number | 128 × 128 | 256 × 256 | 128 × 128 | 256 × 256 | 128 × 128 | 256 × 256 |
STRCC
| 0.0523
| 0.0538
| 0.161
| 0.193
| 0.514
| 0.524
|
Computational conditions: 50 turbulence realizations, open
loop, propagation grids in center; others, see Table
1.
Table 4
Test of Isotropism of Phase Screens (I)
Position
|
x Grid
|
y Grid
| 10 Times
| 20 Times
| 50 Times
|
---|
Left 1 | 65–192 | 193–320 | 0.276 | 0.285 | 0.262 |
Center | 193–320 | 193–320 | 0.229 | 0.214 | 0.238 |
Right 1 | 321–448 | 193–320 | 0.230 | 0.181 | 0.228 |
Upper 1 | 193–320 | 321–448 | 0.315 | 0.372 | 0.362 |
Center | 193–320 | 193–320 | 0.229 | 0.214 | 0.238 |
Lower 1
| 193–320
| 65–192
| 0.238
| 0.210
| 0.181
|
Computational conditions: λ = 0.6328 µm;
L = 340 m; open loop,
C
n
2 = 2.78 ×
10
-14 m
-2/3
(
r
0 = 5 cm); phase screens of the first
kind; phase screen grids, 512 × 512; propagation grids, 128
× 128; ten phase screens.
Table 5
Test of Isotropism of Phase Screens (II)
Position
|
x Grid
|
y Grid
| 10 Times
| 20 Times
| 50 Times
| 100 Times
| 200 Times
|
---|
Left 1 | 65–192 | 193–320 | 0.157 | 0.180 | 0.183 | 0.170 | 0.169 |
Center | 193–320 | 193–320 | 0.161 | 0.166 | 0.161 | 0.164 | 0.164 |
Right 1 | 321–448 | 193–320 | 0.155 | 0.165 | 0.181 | 0.174 | 0.175 |
Upper 1 | 193–320 | 321–448 | 0.205 | 0.168 | 0.161 | 0.165 | 0.164 |
Center | 193–320 | 193–320 | 0.161 | 0.166 | 0.161 | 0.164 | 0.164 |
Lower 1
| 193–320
| 65–192
| 0.216
| 0.198
| 0.178
| 0.179
| 0.167
|
Computational conditions: same as Table
1 except for the
propagation grid position, phase screen of the second kind.
Table 6
STRCC in the Different Turbulent Media
C
n
2
(m-2/3)
| Times
| 10 Phase Screens
| 20 Phase Screens
|
---|
50
| 100
| 200
| 50
| 100
| 200
|
---|
10-14.5
| OL | 0.490 | 0.481 | 0.475 | 0.482 | 0.477 | 0.462 |
AO | 0.855 | 0.854 | 0.853 | 0.857 | 0.854 | 0.852 |
10-14
| OL | 0.161 | 0.164 | 0.164 | 0.162 | 0.166 | 0.160 |
AO | 0.616 | 0.614 | 0.612 | 0.616 | 0.611 | 0.607 |
10-13.5
| OL | 0.0451 | 0.0447 | 0.0448 | 0.0469 | 0.0472 | 0.0451 |
AO
| 0.215
| 0.211
| 0.206
| 0.204
| 0.202
| 0.201
|
Computational conditions: 61-unit AO system; others, see
Table
1. OL, open loop.
Table 7
Strehl Ratio and Phase Variance
σφ
2 without the Overall Tilt of an AO
System
Condition | 1
| 2
| 3
| 4
| 5
|
---|
Iteration Times | STRCC | σϕ
2
| STRCC | σϕ
2
| STRCC | σϕ
2
| STRCC | σϕ
2
| STRCC | σϕ
2
|
---|
0 (OL)
| 0.469
| 4.7568
| 0.469
| 2.0776
| 0.835
| 1.7969
| 0.922
| 0.1573
| 0.338
| 2.3095
|
---|
1 | 0.772 | 4.8937 | 0.772 | 0.5566 | 0.954 | 0.0474 | 0.979 | 0.0200 | 0.762 | 0.3078 |
2 | 0.810 | 5.2581 | 0.810 | 0.4695 | 0.965 | 0.0345 | 0.983 | 0.0146 | 0.818 | 0.2256 |
3 | 0.813 | 5.4267 | 0.813 | 0.3543 | 0.965 | 0.0347 | 0.983 | 0.0147 | 0.818 | 0.2271 |
4 | 0.815 | 5.4437 | 0.815 | 0.2975 | 0.965 | 0.0342 | 0.983 | 0.0145 | 0.819 | 0.2233 |
5 | 0.816 | 5.4341 | 0.816 | 0.2652 | 0.965 | 0.0343 | 0.983 | 0.0145 | 0.819 | 0.2229 |
6 | 0.815 | 5.5034 | 0.815 | 0.2486 | 0.965 | 0.0342 | 0.983 | 0.0144 | 0.819 | 0.2219 |
7 | 0.815 | 5.4999 | 0.815 | 0.2401 | 0.965 | 0.0341 | 0.983 | 0.0144 | 0.819 | 0.2215 |
8 | 0.814 | 5.4735 | 0.814 | 0.2359 | 0.965 | 0.0341 | 0.983 | 0.0143 | 0.819 | 0.2211 |
9 | 0.814 | 5.4757 | 0.814 | 0.2341 | 0.965 | 0.0341 | 0.983 | 0.0144 | 0.819 | 0.2208 |
10
| 0.814
| 5.4707
| 0.814
| 0.2334
| 0.965
| 0.0341
| 0.983
| 0.0144
| 0.819
| 0.2206
|
Computational conditions: λ = 0.6328 µm;
L = 340 m; 37-unit AO system; phase-screen grids,
512 × 512; propagation grids, 128 × 128; ten phase screens;
one turbulence realization. Condition
1:
C
n
2 = 2.78 ×
10
-14 m
-2/3
(
r
0 = 5 cm), before phase
tailoring. Condition 2:
C
n
2 = 2.78 × 10
-14 m
-2/3
(
r
0 = 5 cm), after phase
tailoring. Condition 3:
C
n
2 = 4.455 × 10
-15 m
-2/3
(
r
0 = 15 cm), before phase
tailoring. Condition 4:
C
n
2 = 1.90 × 10
-15 m
-2/3
(
r
0 = 25 cm), before phase
tailoring. Condition 5:
C
n
2 = 2.78 × 10
-14 m
-2/3
(
r
0 = 5 cm); different phase screens,
after phase tailoring. OL, open loop.
Table 8
Comparison of Focusing Calculations with the FFT and the
Integration Method
Times
| OL
| FFT
| Int.
|
---|
1 | 0.338 | 0.819 | 0.819 |
2 | 0.406 | 0.827 | 0.828 |
3 | 0.311 | 0.836 | 0.836 |
4 | 0.268 | 0.826 | 0.826 |
5 | 0.236 | 0.828 | 0.828 |
10 | 0.236 | 0.844 | 0.845 |
20 | 0.221 | 0.840 | 0.840 |
30 | 0.237 | 0.839 | 0.839 |
40 | 0.233 | 0.834 | 0.834 |
50
| 0.245
| 0.834
| 0.834
|
Computational conditions: iteration times, 4;
C
n
2 = 2.78 ×
10
-14 m
-2/3
(
r
0 = 5 cm); others, see Table
7. OL, open loop.
Table 9
Effects of Lateral Wind Speed V on STRCC of AO
Phase Compensation and the Complete Phase Conjugation
V (m/s)
| OL
| AO
| CPC
|
---|
0 | 0.245 | 0.834 | 0.978 |
2 | 0.253 | 0.667 | 0.673 |
4 | 0.254 | 0.443 | 0.412 |
6 | 0.252 | 0.322 | 0.294 |
8 | 0.246 | 0.266 | 0.241 |
10 | 0.252 | 0.232 | 0.208 |
13
| 0.250
| 0.204
| 0.182
|
Computational conditions: delay time, 4.5 ms; 50 turbulence
realizations; others, see Table
8.
CPC, complete phase conjugation; OL, open loop.