Marc Daniel
We installed the new AOM driver for AOM1 in the CLF path. We measured 10.4dBm for the 200 MHz input (no attenuator needed). We adjusted the power gain of the driver to be at the maximum, but we have somewhat less RF power available compared to the old amplifier.
Some measurements at different drive points:
| Drive Point (V) | CLF launch (µW) | RF Readback (dBm) | Power meter (dBm) |
|---|---|---|---|
| 4.7 | 34 | 31.1 | 29.5 |
| 0 | 17 | 27.1 | 26.0 |
| 3.0 | 21 | 28.5 | |
| 10.0 | 47 | 33.4 | 31.4 |
The RF power meter was measuring at the table feedthrough. There is about 1dB loss in the cable from the AOM driver to the table. We chose 4.7V as the nominal for the drive point offset. The lower limit was set at 3.0V, and the upper limit at 10V.
The CLF launch power was 70µW before we switched to the new AOM driver. We have about ⅔ of the previous CLF power at the maximum drive point, and about ½ at the nominal settings. We could probably get most of the previous AOM diffraction power back by implementing an Isomet 505C-2 amplifier instead of the 505C-L, and by using a heliax cable. However, we have plenty of light available in the CLF path before the power adjustment stage, so this is probably not important.