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David Notebook: Difference between revisions
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==Daily Log==
'''10/1/14'''
Diode performance seems good on the OSA too. The peak from the threshold test was single mode and stayed single mode when I increased the current up to the operating value. When trying to set up the locking circuit, it would only occasionally go multi-mode and would quickly return to single mode when I turned down the amount of feedback (previously this would generally require re-scanning with the grating). I never had to touch the grating after the initial threshold test. By the end of the day, I had it locking using just the proportional gain and the first integrator on the Vescent box. The lock would quickly start falling but jump up again before disappearing entirely. This sustained for ~1 min, which is better than I've ever seen. The transmitted power was ~100 mW, which I think is lower than we had previously, but I'll have to look through Josh's notes. I think this will get better when I work with the optical feedback and the other integrator and differentiator. It was so much easier trying to improve the lock since the laser would stay single mode. Much more power is getting to the fiber amplifier too so it never shut off due to low power.
'''9/25/14'''
Ran threshold tests with the diode today--performance seemed good! Better than I had previously seen and better than what Josh had described. There are still multiple peaks at low power (although over a much smaller range than previously) and with the power up to ~0.5 mW (without well adjusted feedback), there is a single very clear spike in power (from ~0.5 mW to 1.3 mW) when adjusting grating position.
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