Development Of High Resolution LCoS Phase Modulator

A spatial light modulator is a key component in the fields of modern optics and optical computing, real-time optical information processing and adaptive optics. It plays an important role in the development of modern optical technology. Based on the technology of liquid crystal on silicon, LCoS phase-modulator can realize real-time, dynamic incident light phase modulate, without changing the amplitude of the light beam conditions. It is widely used in opto-electronic hybrid information processing system. Compared with conventional liquid crystal displays, LCoS devices can provide higher integration, optical efficiency, resolution and can be applied in wider prospects.High-resolution LCoS phase modulator is researched in this paper, including the selection and optimization of operating mode, phase modulation characteristic and improvment, the device assembly flow and testing. First of all phase modulation of different liquid crystal cells are compared and the anti-parallel electrically controlled birefringence (ECB) mode is applied to the device. Its working principle and the design of the structural parameters are introduced. In simulation experiment the basic phase modulator device performance was simulated and optimization methods were proposed to improve fringe field effect by the way of adjusting driving voltage and the liquid crystal cell structure. Under the guidance of the simulation results, the LCoS phase modulator samples were made in advanced fabrication process. Cell thickness and uniformity were under strict control. Finally testing systems were built, which used amplitude modulation and Digital Holography to complete phase modulator functional testing, The amount of phase modulation reaches 2? and depth and scope of phase modulation were evaluated in the various aspects.