Characterization of twisted liquid crystal spatial light modulators

A spatial light modulator (SLM) is a very useful optical tool due its versatility to be manipulated dynamically. We propose a characterization method for reflective SLMs in quasi-normal configuration. This device can work as either amplitude-mostly or phase-mostly modulator. To achieve the modulation, the SLM can be accompanied by two polarizes, or additionally using a quarter-wave plate retarder. By simulating the behaviour of the optical setup for this device; we establish an experimental Jones matrix that represent the modulator. In this work we present a more realistic modulator characterization, only assuming that the modulator Jones matrix should be unitary (the modulator do not absorb light). We report this model for characterization of the Holoeye LCR2500 SLM.