Characteristics of a spectrum-slicing filter composed of an angle-tuned Fabry-Perot etalon and a Gaussian input beam

We present the first analysis of the spectrum-slicing filter composed of an angle-tuned Fabry-Perot etalon and a slightly divergent Gaussian input beam. The channel bandwidth is strongly dependent on the minimum beam spot size and the refractive index of the etalon substrate but insensitive to other etalon parameters. The channel center and the channel power resemble closely those of the pure plane wave incidence case. Fortunately, the channel shape evolves from the Lorentzian to the more favorable Gaussian as the channel bandwidth increases.<>