【摘要】 利用3级滤波结构,实现了对声光可调谐滤波器(AOTF)的旁瓣抑制。根据耦合模理论分析了共线型和准共线型AOTF的滤波原理,推导出3级级联滤波的转换特性表达式:计算结果表明,3级滤波结构能够有效地抑制旁瓣。实验测定表明,旁瓣被抑制到-27dB左右,并且滤波带宽也得到了压窄。更多还原

【Abstract】 The large sidelobes higher than -9 dB of the single-stage acousto-optic tunable filter(AOTF) may limit the application.In order to suppress sidelobes further,a triple-stage AOTF is stuied.The theory of single-stage collinear and quasi-collinear AOTFs is analysed,and then the transfer function of the triple-stage filter is obtained.The calculated results demonstrate that the triple-stage device can provide significant improvement in sidelobe suppression;Experimental measurement shows that sidelobes are suppressed to -27 dB and the bandwidth is narrowerd.更多还原