A Phase Control Method for Small Beam Deflection Based on Liquid Crystal Spatial Light Modulator

Abstract

The invention discloses a small beam deflection phase control method based on a liquid crystal spatial light modulator, which belongs to the technical field of non-mechanical beam deflection in an active optoelectronic system. It is mainly aimed at the problem that the stability of the actual scanning point is easily affected by the alignment error between the light source and the modulator when the original sub-aperture coherent method realizes the high-precision scanning of the small beam. The phase generation method mainly divides the effective modulation area of ​​the modulator into two groups of symmetrical fan-shaped structures, and respectively loads the adjacent interval angles that can be scanned by the traditional variable period grating method, and changes the area ratio of the two symmetrical fan-shaped areas to obtain Other finer angles between the corresponding angles of the final two regions are achieved. At the same time, when the center of the input light spot deviates from the center of the modulator panel, this method can make the ratio of the energy of the beam falling into the two regions relatively stable due to the energy complementation effect brought by the double sector structure, thereby achieving high overall stability of the scanning spot array. This method can be applied to centrosymmetric beams with any millimeter-scale aperture, and can greatly relax the system's adjustment accuracy restrictions while maintaining the original radial sub-aperture coherent scanning accuracy, and at the same time improve the deflection angle's impact on external mechanical vibrations. resistance. This improvement in stability can effectively enhance the value of phased array technology for high-precision beam deflection control.

Description

technical field [0001] The invention relates to a phase control method for realizing high stability and high precision beam deflection by utilizing a liquid crystal spatial light modulator, and belongs to the technical field of non-mechanical beam deflection in an active photoelectric control system. Background technique [0002] Beam deflection technology is widely used in lidar, laser communication, laser imaging and remote sensing, and far-field beam shape control. The traditional beam deflection technology generally relies on mechanical devices to achieve beam deflection control by changing the direction of the optical axis, which has the disadvantages of complex structure, large volume, high cost, and high energy consumption. The new beam deflection technology represented by the optical phased array technology realizes the purely electronic deflection of the beam, overcomes many shortcomings of the traditional mechanical beam deflection technology, and shows its huge ap...

AI Technical Summary

Problems solved by technology

Traditional beam deflection technology generally relies on mechanical devices to achieve beam deflection control by changing the direction of the optical axis, which has the disadvantages of complex structure, bulky, expensive, and high energy consumption.

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