A direct comparison between the transmitted arm powers between O2 and now. The input power during O2 (8/1/2017) was 28W, whereas it is 30W now.
| Mirror | O2 | Now | Change |
|---|---|---|---|
| ETMX | 3.6 ppm | 3.9 ppm | +8% |
| ETMY | 3.6 ppm | 3.8 ppm | +6% |
The errors for the transmission coefficients are listed as ±0.2 ppm.
| Channel | O2 | Now | Change | Corrected for Transmission |
|---|---|---|---|---|
| H1:ASC–X_TR_A_NSUM | 106k | 147k | 1.38 | 1.28 |
| H1:ASC–X_TR_B_NSUM | 141k | 194k | 1.38 | 1.27 |
| H1:ASC–Y_TR_A_NSUM | 144K | 211k | 1.47 | 1.39 |
| H1:ASC–Y_TR_B_NSUM | 153K | 225k | 1.47 | 1.39 |
The average power increase between the two arm cavities is 1.33. Or a factor of 1.24, if corrected for the input power. This isn't compatible with our observed increase in the power recycling gain by factor of about 1.5 (from ~30 to ~45). There is also a fairly large imbalance between the two arms, indicating there may be an inaccuracy in the optical transmission data? or?