Photonic integrated circuit for high-wavelength-channel-count wavelength-division-multiplexed systems

Abstract

The present disclosure is directed toward architectures that combine DWDM and CWDM concepts in a single PIC. Transmitter stages in accordance with the present disclosure include a plurality of multiwavelength lasers having regions of separately grown epitaxial material whose gain peaks are centered at different wavelengths. Each laser launches a wavelength comb comprising a plurality of wavelength signals into a PLC, where the wavelengths within each wavelength comb are separated by a wavelength spacing that is smaller than that between adjacent wavelength combs. In some embodiments, the PLC includes modulator banks for encoding data on the wavelength signals and combining them to produce a composite DWDM output signal. In some embodiments, a receiver stage is included for demultiplexing a composite DWDM input signal and detecting each wavelength channel within it. In some embodiments, the receiver stage employs polarization-diversity techniques to enable it to operate on unpolarized/randomly polarized input signals.