Checking your paper â€˜ controlling light through optical disordered media: transmission matrix approachâ€™, the region of SLM is divided into two parts: one is reference part and the other is controlled part.

So my questions are:

1) the measurement is proceeded by sending the hadamard basis on the controlled part while the reference part remain unchanged and then get the signal from CCD. So once the measurement is completed, equation 7 can give us the observed transmission matrix directly, right? But the intensities are obtained from hadamard basis instead of canonical basis. So the equation 7 maybe is not for the hadamard basis so that a unitary transformation is needed? If so, how to reconstruce the transmission matrix by getting the signal generated by hadamard basis?

2) if I want to optimise for optical focusing, following equation 16 can calculate the corresponding optimised phase pattern, so is the phase pattern displayed on the controlled part of the SLM directly? if so, will there be a problem leaving the reference part unchanged? I am concern about that the reference part can still reflect light into the scattering medium, which will interference with the optimised phase pattern on the controlled part.

looking forward to your reply.]]>

However, I am now trying to use that TM to engineer a particular field at my detector (e.g. a focus) or sense (e.g. detect a pattern portrayed on the SLM) but am running into some trouble. My primary confusion seems to come from how to use this TM. Using Eq. 16 in said paper, I can calculate the the input field needed to yield a desired output field. The TM is a complex matrix, the field is complex and when I do this calculation, I yield another complex matrix (after reshaping). Since, I'm using an SLM to engineer the phase, then I extract the associated phase profile and display that on the SLM.

Unfortunately, this does not seem to yield the desired result at the detector plane. Any suggestions or tips would be greatly appreciated.

Thanks,

Chris.]]>