Research on active SLM device structure of deep sub-wavelength F-P resonance

Abstract

A deep sub-wavelength metal grating is used to replace the top electrode of liquid crystal on silicon (LCOS) to form a new structure of liquid crystal (LC) phase spatial light modulator (SLM), which to meet large spatial bandwidth product of dynamic holographic video display. Although the structure of this (gold) deep sub-wavelength grating-LC-metal electrode is similar to the geometry of the current LCOS, the physical mechanism is completely different, which we called it G-LCOS. In order to study the feasibility of the new G-LCOS for phase modulation of digital holographic display, based on previous calculation and simulation, we fabricate deep sub-wavelength gratings by using EBL and obtain a conceptual verification device by referring to the traditional LCOS process flow. In this paper, we present experimental investigations based on Michelson's interference principle on the phase modulation performance of this proof-of-concept device. The results show that the phase modulation of the structure can reach 1.2π. The slight disagreement between the theoretically predicted and the experimentally measured values for the G-LCOS phase modulation could be caused by the errors in the preparation process and measurement.