12 posts

I record a speckle pattern using off axis digital holography. However if I take consecutive shots with nothing being changed, I see that the correlation of the Hologram intensity reduces with that of the first shot. Due to which my reconstruction gives different recobstructed field at different times. My laser is stable. I dont see the speckle pattern changing visually in the camera. However the noise seems degrading my signal. Can you please help me with it.

Is the transmission matrix of a scattering medium a unitary matrix ?

How can I measure the error between two speckle intensities. ?


I am trying to project a random phase mask in which each pixel varies from 0-2pi.

I am using a phase only SLM. I understand that the if we need to get a phase pattern we need to use gerchberg saxton algorithm and back calculate that phase that would produce that, then match it with the gray levels of the SLM and inject the pattern on it. By pacing lens at f of the lens we get the required pattern.

But my question is what if Image SLM on to the sample. Will I get the same phase pattern

Hi I am using a HoloEye Phase only SLM. I would like to illuminate my scattering medium using a line illumination.

For which I made a collimated laser beam. Then used a cylindrical lens to get line illumination on the SLM. Out of 1920x1080 pixels I want the phase variation only in the 960th column. For I which I created a phase mask with only enteries in the 960th column and loaded ito to the SLM. And this is the illumination that I want on my scattering medium. Unfortuately I get the light reflected from the SLM completely. How can I make sure that SLM reflects only the line I loaded?

Please can you help me