Eli notebook

ECDL Tuning

7/14/15

Tuned a 785nm laser by keeping current fixed at 68.5mA and ramping the grating piezo from 0 to 150V. Got a pretty decent plot of frequency vs piezo voltage with clear mode hops. Decreasing the voltage from 150V to 0V yielded a messier plot with more random mode hops. In all, the laser tunes with a rate of about .16 GHz/V.

To get an idea of how the laser tunes with current I tried eliminating the external cavity by removing the grating but the laser was pretty unstable this way and wouldn't stay single mode even while keeping the current fixed. So I attached the grating and I tried to tune the laser by keeping the piezo at a fixed voltage while varying the current. I'm now trying to find a piezo setting that allows a workable range of single mode while changing the current so I can get get some good data. I'm also unsure if having the external cavity while varying the current changes the tuning rate as opposed to tuning the laser diode without the grating.