激光与光电子学进展, 2019, 56 (15): 152502, 网络出版: 2019-08-05
基于相位调制的光纤干涉型光学相控阵扫描特性研究 下载: 885次
Scanning Characteristics of Fiber-Optic Interferometric Phased Array Based on Phase Modulation
光电子学 光学相控阵 光纤干涉 相位调制 扫描电压 optoelectronics optical phased array fiber interference phase modulation scanning voltage
摘要
为解决光纤干涉型相控阵在实际实用中的扫描控制问题,建立了一种基于相位调制的光纤干涉型光学相控阵扫描控制的理论模型。该模型以光纤作为相控阵阵元,采用傍轴近似和远场近似,通过加载在相位调制器上的扫描控制电压实现光束的扫描;讨论了一种扫描电压的[-π,π]加载方式;对扫描角度、阵元间距,以及相位调制器参数间的关系进行数值分析,还验证了相控阵路数与调制系数对扫描分辨率的影响。结果表明:通过[-π,π]的扫描电压加载方式,可以把控制电压控制在±V π(半波电压)范围内;在相控阵阵元间距一定时,随着相位调制器长高比的增大,在小角度范围内,扫描角度呈线性增大;相控阵路数越多,调制系数越小,分辨率也就越高。在一维光纤阵元间距为125 μm时,当相位调制器的长高比为10
3量级时,最大扫描角度可达0.1 rad;当调制系数为0.3,一维光纤阵元为50时,扫描分辨率可达210。
Abstract
A theoretical model of the scanning control for a fiber-optic interferometric phased array based on phase modulation is proposed to overcome the limitation of scanning control for a fiber-optic interferometric phased array in practice. This model uses optical fibers as the phased-array elements, adopts paraxial and far-field approximations, and uses the scanning-control voltage loaded on the phase modulator to realize the scanning of the beam. A [-π, π] charging scheme of scanning voltage is proposed. The relationship among scanning angle, element spacing, and parameters of the phase modulator is numerically analyzed, and the influences of the phased-array path number and modulation coefficient on scanning resolution are verified numerically as well. Results show that the voltage is controlled within ±Vπ (half-wave voltage) by the [-π, π] charging scheme; when the spacing of the phased-array elements is constant, the scanning angle increases linearly with an increase in the length-to-height ratio of the phase modulator in the small-angle range; the higher the number of phased-array beams and the smaller the modulation coefficient, the higher the resolution. The maximum scanning angle can reach 0.1 rad when the length-to-height ratio of the phase modulator is 10
3 orders of magnitude and the spacing of the fiber-array elements is 125 μm, and the scanning resolution is 210 when the modulation coefficient is 0.3 and the number of fiber-optic elements is 50.
任远中, 柴金华. 基于相位调制的光纤干涉型光学相控阵扫描特性研究[J]. 激光与光电子学进展, 2019, 56(15): 152502. Yuanzhong Ren, Jinhua Chai. Scanning Characteristics of Fiber-Optic Interferometric Phased Array Based on Phase Modulation[J]. Laser & Optoelectronics Progress, 2019, 56(15): 152502.