Here's a comparison of the different objective functions I've been playing around with. Clearly the maximum intensity sucks, flat at both the minimum and maximum. The moment of inertia (J) works well, but requires quite a shitload of filtering and thresholding to purge all the noise. The std2() function also works well, and even has a nice distinct peak value. Ultimately, although I've spend a lot of time on the moment of inertia, the std2() objective is hard to ignore for its simplicity.
To my amazement, it wasn't hard to get the SPGD controller working with this objective function, even with multiple modes. For the first time I was able to maximize an objective function using only the image of the beam profile. Exciting I know. Convergence is pretty shitty in this case, but I think it can do better with a larger control gain. In response to the questions posed yesterday:
1. Multiple modes works!
2. Still unknown, but its close.
3. Slight improvement when log(std2()) is used, but it isn't necessary or dramatic.
4. Should be possible.
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