Modeling and performance analysis of focused coherent beam combining based on liquid crystal optical phased array

An approach to focused coherent beam combining (CBC) is proposed. Based on the beam steering technology by liquid crystal optical phased array (LCOPA), a combined beam can be obtained in an arbitrary position within the target region. A theory model of CBC is built based on practical parameters. When 5 coherent beams are combined in position with 100 m distance and 2 m coordinate, the value of peak intensity increases to 16.9 times. Trends of peak intensity in the target region are researched. Analysis indicates that the direct reason for beam jitter is the distortion of the phase front, and the deeper reason is the error of the phase delay caused by voltage quantization. When the quantization bit is less than 16, the position error decreases and the peak intensity increases as the quantization bit increases. However, when the quantization bit is greater than 16, the quantization bit is not the main reason any more. As the transmission distance is larger than 5000 m, the focused CBC is equivalent to the parallel CBC. The peak intensity increases to N2 times when the number of coherent beams is N. Research results can lay a foundation of the application of LCOPA in CBC.