5.19.09

Last weekend I ran a couple long SPGD experiments with and without the SLM to see if it had any noticeable effect on the performance. I ran each lasted for around 10,000 iterations, and since I can only update the SLM every 3 seconds they each took over 8 frickin hours to run. I feel like a biologist.



For the "w/ SLM" case the image was set to a focus with a sinusoidally varying intensity such that the maximum phase distortion occurs at the center of the focus at the peak sinusoidal amplitue. Maybe I'm just cynical, but its not really clear to me that the SLM has any effect. Its nice the the algorithm can sort of maximize the image cost function (J), ignoring those unexplained spikes, but its hard to distinguish any difference between the 2 cases. Control starts at k=1000.

Here's a close up of a section of the uncontrolled iterations.



The SLM obviously has an effect on the objective function, but its not much, and it doesn't look like that effect more than the noise from calculating the image objective function. What is clear though is that unless I can speed things up, using the SLM at all is totally impractical. This 3 second bullshit can't go on if I'm going to really be using it.