Wavelength multiplexer-demultiplexer having a wide flat response within the spectral passband

Abstract

A wavelength demultiplexer having a substantially flat output response within its passband is disclosed. The demultiplexer comprises a first wavelength demultiplexer optically coupled to a second wavelength demultiplexer. The first wavelength demultiplexer has a free spectral range approximately equal to channel spacing of the second wavelength demultiplexer thereby providing the substantially flat output response within the passband. The first wavelength demultiplexer is a resonant optical cavity, absent distinct output ports, and light propagating between the first wavelength demultiplexer and the second wavelength deimultiplexer is unguided. The absence of distinct output ports in the first wavelength demultiplexer reduces ripples in the substantially flat output response within the passband. Alternatively, the first wavelength demultiplexer is replaced by an MMI-phasar.

Dependencies are inferred from the claim text.