Spectral response characteristics of concave grating demultiplexer

Abstract

Based on the characteristic of vector waves which taken part in the multiple beams interference in the focal field of concave grating demultiplexer, the reversibility between emission efficiency and receiving efficiency of the optical waveguides, and the amplitude superposition theorem of multiple beams interference, an original analytic expression of simple spectral response efficiency of concave grating demultiplexer is derived. As the spectral distribution of the actual input optical signal is considered, the Gaussian function spectral distribution for example, the actual responsibility and crosstalk of the concave grating demultiplexer for this input optical signal are introduced. Several analytic expressions offer some useful foundation and novel method for analyzing the responsibility and crosstalk of concave grating demultiplexer. A computing instance of concave grating demultiplexer is given, this instance shows that the actual response efficiency characteristic curve which engaged the Gaussian function spectral distribution of input optical signal is smoother than the simple spectral response efficiency characteristic curve which ignored input optical signal spectral width, the smoothness of actual response efficiency characteristic curve and the actual responsibility are dependent on the spectral half width at one of e square of the maximal intensity of actual input optical signal.