基于虚像相位阵列的锯齿形滤波器研究

Research on Jammed-array Wideband Sawtooth Filter Based on Virtually Imaged Phased Array

边缘滤波器被广泛地应用在光纤光栅传感中,其工作原理是将波长偏移量转换成光功率的变化,具有响应速度快、动态检测范围大的优点。为了实现一种周期性边缘滤波器——低损耗锯齿形(JAWS)滤波器,提出并验证了一种有限反射虚像阵列(FRVIA)。FRVIA具有较低的后端面反射率,其输出光强分布、光谱分辨率、输出孔径等方面与VIPA存在显著差异。通过数值仿真,对低损耗滤波器的参数进行优化,实现了占空比高达70%、损耗低于14 dB的低损耗JAWS滤波器。

Edge filter has been widely used in fiber grating sensing systems and the principle is to convert the wavelength offset into the change of optical power,which has the advantages of fast response and large dynamic detection range.In order to achieve a periodic edge filter named low-loss jammed-array sawtooth(JAWS)filter,a finite reflection virtually imaged array(FRVIA)is proposed and demonstrated.Comparing with virtually imaged phased array(VIPA),FRVIA has a low reflectivity in the back side,with the differences of output light intensity distribution,spectral resolution and output aperture and so on.By numerical simulation,the parameters of the low-loss JAWS filter have been optimized,a low-loss JAWS filter has be achieved with up to70%duty cycle and lower than14dB loss.