The Research Of Inertialess Light-beam Scanning Control Technology

Traditional laser scanning devices are composed of many mechanical components, and the shortcomings of these devices are huge, weight greater usually. Resulting in the structure of these scanning devices has great inertial, so these equipments may have obvious backward and advance phenomenon. Do not satisfy fast, flexible and accurate control direction of the beam, and we need use a lot of computers achieve the launch of multi-beam, capture, tracking rather than a computer. They are difficult to achieve the miniaturization of the device requirements.Based on optical phased-array technology of liquid crystal spatial light modulator (LCSLM, Liquid Crystal Spatial Light Modulation), as many have overcome the above drawbacks of the new programmable diffractive optical components are being widely application. As phase-only liquid crystal spatial light modulator can be achieved continuous phase modulation, which makes it applicable to space beam steering, so its has broad application prospects on laser phased array radar and free-space optical interconnects, and other fields.This paper focuses on liquid crystal spatial light modulator beam scanning control applications. The main researches are as follows.(1) Continuous elastic body theory and electrically controlled birefringence (ECB) are given. The distribution of liquid crystal director can be calculated by difference iterative method, and the relationship between the refractive index of extraordinary light and the position is illuminated.(2) The diffractive efficiency and the condition to realize blaze and scan are derived by Fourier transform and binary optics.(3) In this paper, we use LCSLM made by BNS. A new-style liquid crystal blazed grating is simulated by LCSLM. According to the phase-only characteristic of LCSLM, the liquid crystal blazed grating has an equivalent transformation which is called echelon blazed grating made of glass with a constant refractive index for a certain wavelength. Finally we achieve a inertialess scanning light-beam control. This paper proposed by the electronically controlled liquid crystal spatial light modulator simulation blazed grating has many advantages compared with conventional blazed gratings. The parameters like grating constant, blazing angle and the refractive index for one certain wavelength of the conventional blazed gratings can not be changed when they have been made. So they limit their applications. All of these parameters of the liquid crystal blazed gratings can be changed easily by modulating the external electric field. The best advantage of the liquid crystal blazed gratings is that they can realize scan on every wavelength. Besides the properties to realize blaze and scan, the liquid crystal spatial light modulator can also be used in many other fields, such as beam splitter. It also has a smaller body and weight than traditional scanning devices.