Phase engineering applied to integrated optical filters

Optical filters are an enabling technology for high density, high bitrate WDM systems. Filters are required for a wide variety of tasks including (de)multiplexing channels, gain equalization and dispersion compensation. As the number of channels, utilized bandwidth of the fiber, spectral efficiency, and bitrate per channel increase, the demand for high performance, compact filters with greater functionality and integration increases. Optical allpass filters are compact and easily fabricated in planar waveguides, offer new functionality such as dispersion compensation, and yield more efficient architectures (i.e. fewer stages) for realizing bandpass filters