We calibrated the measured beam power at POP and POS for reflection/transmission imbalance for s-pol and p-pol. The following table shows the calibrated power of s-pol and p-pol. For power at POP, we calibrated the effect of central BS (R:T=50:50 for s-pol and R:T=20:80 for p-pol [1]) and the effecct of RBS1 (T=48% for s-pol and T=78% for p-pol). For power measured at POS, we only calibrated the central BS effect. The round-trip loss is calculated using this method. If there is birefringence, in principal, we should use the total power (s-pol + p-pol) to calculate the round-trip loss. If we only use s-pol, the round-trip loss will be under estimated.
| Measrement at POP | |||||||
| POP SUM/EXP | POP_P SUM/EXP | Calibrated s-pol | Calibrated s-pol | Total power | P-pol content | Round trip loss (ppm) | |
| X single | 6533.3 | 820 | 27222.08 | 1314.103 | 28536.19 | 4.605039% | 72.55784 (Use s+p power) |
| X lock | 6400 | 75 | 26666.67 | 120.1923 | 26786.86 | 0.448699% | 27.11463 (only use s-pol) |
| Y single | 6266.7 | 460 | 26035.31 | 2948.718 | 28984.03 | 10.17359% | 80.28122 (Use s+p power) |
| Y lock | 6400 | 65 | 26589.12 | 416.6667 | 27005.78 | 1.542879% | -19.1902 (only use s-pol) |
| Measrement at POS | |||||||
| PD s-pol | PD p-pol | Calibrated s-pol | Calibrated p-pol | Total power | P-pol content | Round trip loss (ppm) | |
| X single | 1919 | 50.7 | 3838 | 253.5 | 4091.5 | 6.195772% | 33.36619 (Use s+p power) |
| X lock | 1933 | 23.8 | 3866 | 119 | 3985 | 2.986198% | -3.66163 (only use s-pol) |
| Y single | 1785 | 342 | 3570 | 427.5 | 3997.5 | 10.69418% | 49.959 (Use s+p power) |
| Y lock | 1830 | 139 | 3660 | 173.75 | 3833.75 | 4.532116% | -23.5668 (only use s-pol) |
For comparison, we calibrated the measured beam power at POP by Matteo in klog#21759 and klog#21777.
| POP SUM/EXP | POP_P SUM/EXP | Calibrated s-pol | Calibrated p-pol | Total power | P-pol content | Round trip loss (ppm) | |
| X single | 6750 | 859.6 | 28043.21 | 1377.564 | 29420.77 | 4.682284% | 300.6861 (Use s+p power) |
| X locked | 5125 | 177.6 | 21292.06 | 284.6154 | 21576.68 | 1.319088% | 271.9342 (only use s-pol) |
| X single | 6800 | 886.5 | 28250.93 | 1420.673 | 29671.61 | 4.787988% | 330.4912 (Use s+p power) |
| X locked | 4933.3 | 292.7 | 20495.64 | 469.0705 | 20964.71 | 2.237429% | 309.4608 (only use s-pol) |
| Y single | 7250 | 484.9 | 30120.48 | 3108.333 | 33228.82 | 9.354331% | 77.74787 (Use s+p power) |
| Y locked | 7276.1 | 126 | 30228.92 | 807.6923 | 31036.61 | 2.602386% | 0.444444 (only use s-pol) |
| Y single | 7163.7 | 468.1 | 29761.94 | 3000.641 | 32762.59 | 9.158743% | 56.81537 (Use s+p power) |
| Y locked | 7337.9 | 114.3 | 30485.67 | 732.6923 | 31218.36 | 2.346992% | -22.5745 (only use s-pol) |