Design of a Thin-Film-Based Optical Filter for Broadband Multichannel Communication Systems

This paper is concerned with the design of an optical filter, based on thin-film interference, for multichannel optical communication systems with Ta₂O₅ and MgF₂ materials for 1550 nm operation. The performance of the filter configuration is analyzed and the numerical results of the optimization parameters, such as central wavelength, 3-dB bandwidth, figure of merit and ripple in the passband, are reported. The variation of these parameters is also studied for various modified filter configurations. The angular performance of the filter is investigated in terms of the polarization-dependent loss and spectral shift of transmittance towards shorter wavelengths.