Study On Technology Of Spatial Light Modulation By Electrical Addressing

Spatial light modulation is a kind of technique of high integration. It is usually figured out as using multiple methods to process the transfer condition of light spatially and is widely used. On behalf of Pockels effect of electro-optic crystals, or Kerr effect, various electric addressing spatial light modulator can be developed to realize electrically driven spatial light modulation, so as to control such transfer conditions as converging, diverging, defecting and transferring. Electric addressing modulator overtakes other kind of addresser definitely in such field as optical interconnect communication, laser scanning or light memory, which requires devices of considerable corresponding speed and high precision.In those books of electro-optics effect, liquid crystal (LC) material possesses the advantage of low driving voltage, wide modulating range etc, and is taken care of superiorly. Now, people are trying to use various methods, including the electro-optics effect of LC, to modulate the wavefront of light or modulate its phase after scattering the wavefront. In this field, discrete modulating, continuous modulating, hybrid modulating etc. are designed. Each method possesses its advantages and disadvantages.In this paper, in the course of studying the physical principles of electro-optics effect of LC, the Freedericksz transformation (parallel alignment nematic configuration LC along surface) is analyzed thoroughly on the base of Frank elastic continuum theory. After connecting the LC molecule director's orientation distribution law in the apparatus with the equation of refractive indices ellipse in crystal optics, the calculative relation between the density of light phase modulation and the outer electric field and a set of effective methods to solve the effective refractive indices of LC film are set up. Basing on this theory, and taking on optical interconnection as applied background, a kind of design of LC beam steering, which can realize electro-optic deflection, is put forward. The device of this design can be used to realize the 1X2 interconnect operation of light's electric addressing, and because its character of easy integrating, if used cascadedly, the 1 X N interconnect can be obtained. In this paper, the functions and structures of device, the choice of main parts and its functions and characters are also presented. After strictly calculating and deducing the optic character of the theoretical model of the device in virtue of the scalar diffraction theory, the expected optic purpose of device designing is validated. And, the influence from each physical factor on optical result turns out in this course. It can bring principle reference to the further design of device. According to the simulating calculation, when using this beam steer under a driving voltage of 10 volt, the 10?refraction of 1.Sum incident light can be abstained. And, a wider range can be reached, which will fulfill our future need, if it is used cascadedly.Comparing with those former corresponding designing, the best character of this beam steering is that it is easy to control and easy to realize the digital electric addressing operation, and it circumvents those regular difficulties lying in themicroelectodes array. Those difficulties are very rigor in the design of LC electro-optic steering modulation. Thus, it ensures a pretty work efficiency and decreases the processing difficulty. Accordingly, the value of this design is apparent. It brings the utilization of the LC electro-optic steering technique a new step.