Abstract

Spatial Light Modulators (SLM) performing the function of adaptive phase modulating elements have a wide variety of useful applications such as switchable holographic optical interconnection.¹ A very attractive generic type of SLM is the Ferroelectric Liquid Crystal over Very Large Scale Integration (FLC/VLSI) SLM.² This device has a FLC cell fabricated on top of a custom designed VLSI silicon backplane. The backplane contains an array of pixel memory elements, pixel mirrors, and addressing circuitry. The controllable pixels in the SLM modulate the relative phase by exactly 0 or π due to the switchable uniaxial nature of the FLC structure. Only recently has the full potential of these devices become made available through planarisation techniques. By burying the VLSI circuitry under films of oxides and then mechanically polishing the wafer, as one might polish a mirror, large fill-factor mirrors with a high optical quality have been achieved. Such a high optical quality is crucial if the devices are to be truly useful in high performance optical systems.

© 1994 IEEE