Optical interleaver based on multicavity Fabry-Perot thin film filter

A simple and low-cost solution for interleaver used in optical communication, based on multi-cavity Fabry-Perot optical thin film filters, is presented. The analyses on this kind optical interleaver reveal the influencing factors that would affect the thin film interleaver performance, including the cavity's spacer thickness, ambient temperature variation, dispersion for the refractive index of deposited material depending on wavelength and the numbers of cavity that is important for passband flatness and isolation. The interleaver achieved to 100GHz-spaced channels, at wavelength around C band, with adjacent channel's cross-stalk less than —25dB and the minimum insertion loss nearly 0.4dB or so.