【摘要】 锯齿形光谱(JAWS)滤波器的光谱成分比较复杂,是一种较难实现的光谱滤波器。本文通过数值仿真对基于虚像相位阵列(VIPA)的JAWS滤波器的主要参数如线性度、占空比和信噪比(SNR)等进行了优化,并进行了实验验证;通过对JAWS滤波器插损的分析,将反射式的工作方式改变为透射式的工作方式,使整个滤波器的附加损耗从20dB减小到小于6dB;同时,滤波器的性能也有了明显的进步。更多还原

【Abstract】 Jammed-array wideband sawtooth(JAWS)filter has periodic multi-channel sawtooth spectrum.Due to the complex spectral components,it′s difficult to make a passive multi-channel sawtooth filter.In this article,we present a modified JAWS filter with low loss.It only consists of four elements,including a fiber collimator,two lenses and a virtually-imaged phased array(VIPA).The beam transmitted through the VIPA is collected by a lens and a large area photodetector rather than a mirror is used to reflect the beam back into the fiber.The extra insertion loss is lower than 6dB and the performance of the filter is much better than that of the JAWS filter with beam reflected by a mirror.The main characteristics of the jammed-array wideband sawtooth filter based on a virtually-imaged phased array are studied systematically.The main parameters,such as linearity,duty cycle and signal-to-noise ratio,are optimized by numerical simulation and tested by the experiment.Since the free spectrum range of the filter is decided by the thickness of VIPA,the optimization of VIPA with different thicknesses is also discussed.The filter might be used in fast sensitive interrogation of concatenated multi-channel fiber Bragg grating sensors and ultra-high-frequency electrical sawtooth waveform generation.更多还原