I'm not totally convinced the SLM is doing much to the phase. I'm pretty sure its working, but since I'm not measuring the phase directly I don't know if a single wavelength of change is much.

It's clear that something is happening. Here's a plot of the target image variance (J) and slope vector norm with the SLM active. At 300 iterations it displays a focus shape (not that easy to calculate efficiently!) where the amplitude varies sinusoidally from the max displacement to min.



The good news is that the sinusoidal pattern is reflected in both objective functions. But although the change is visible, its miniscule percentage compared to what's available with the DM. As a comparison, the maximum stroke of the DM is in the range of 10 microns. The SLM is limited to 2pi rad, about 650 nm. This wouldn't matter much if I were mapping the phase measurement back to the range of [0,2pi], such as with a SRI. But since I'm not measuring the phase directly, I'm not sure how variations like that are mapped in a Hartmann sensor.

The other problem is the ludicrously slow response time of the SLR, which I still have to limit to 1/3 Hz. Given the shit this thing has given me over the last few months, I think the best plan of action is to convince my advisor to ditch the SLM and get another DM. That will require me to exhaust all obvious ways to speed things up, but at this rate that shouldn't be hard.