The use of a commercially available LCD panel of an overhead projector is suggested for coherent optical processing as a low cost SLM in this paper. The LCD panel is used as a spatial light modulator for inputting the image to be processed in real time.
Subhash C. Jain,
S. D. Mehta,
"Overhead projector LCD panel for image processing", Proc. SPIE 1970, Systems-Oriented Optical Design, (10 August 1993); doi: 10.1117/12.155837; https://doi.org/10.1117/12.155837