Jared lab notebook

--Jmiles2 (talk) 12:39, 13 May 2014 (CDT)

I need close to 17 mW of seed power for the 2nd FORT beam to work at 2 Watts. Although this is is in the range of acceptable powers for this TA I still want to contact M2K lasers and make sure the Intensity is not too high. I can only get about 40% through the AOM when powering it with 2 Watts. I get around 33% out of the fiber at higher power (~600 mW). I get over 200 mW from the output of the fiber.
Need two AWG outputs for evaporative cooling of both FORT lasers. For the FPGA, FORT on/of Channel 14, is a switch to the FORT 1 amplifier, and turns it on or off. The RF in to the amplifier is controlled by the AWG which is triggered from CHannel 10, FORT AWG. OFF means the AWG is triggered.

--Jmiles2 (talk) 14:25, 14 May 2014 (CDT) For the AWG/hittite chip on FORT 1, 3db input on CW setting is equivalent to 33 to 33.2 dbm output power, 2 Watts, maybe a tad more. Since I'm not running this all the time, I think slightly more than 2 Watts should be fine. On pulse setting, 0 V input gives 11.5 dbm and -700 mV gives 32.8 dbm. A little over 20 dbm attenuation, that should work fine for what we're doing. The majority of attenuation happens from 0 to -200 mV.

I made an identical circuit for FORT 2. at 0 V, the output is 33 dbm for 4.5 dbm input power. The input power might change based on what RF generator you use, always check it first. At 700 mV the output is 4 dbm, 29 dbm range, I think the circuit for regulating the current to the chip is slightly off in the FORT 1 circuit. 4 dbm input give 33 dbm at CW setting.

--Jmiles2 (talk) 11:05, 15 May 2014 (CDT) Need to get FORT 1 laser to one polarization. Alignment affects polarization, looks like most of the light is vertically polarized. 19 amps give me 20 Watts in vertical direction. ~20 Watts is max for the AOM. Put in a wave plate to change to horizontally polarized so it would go through the beam cube. Still get good efficiency through beam cube, 45% to 50% at high powers.