Patent ID: 11968035
Assignee: ACACIA COMMUNICATIONS, INC.
Field: Telecommunications (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 9:
10. A system, comprising:
an optical transmitter, comprising:
a digital signal processer (DSP); and
an integrated optical multiplexer, comprising:
a photonic integrated circuit comprising
a plurality of inputs operable to receive a plurality of optical input signals, and
two or more stages of multiplexing in a cascading configuration, wherein the two or more stages of multiplexing are divided into wavelength stages and a last stage,
wherein each of the wavelength stages combine subsets of the input signals by wavelength, the last stage combines the optical signals by polarization using a polarization beam combiner, and at a combined output of the integrated optical multiplexer a first subset of the input optical signals have a different polarization than a second subset of the input optical signals, wherein one or more of the wavelength stages comprise one or more mach-zehnder interferometers, wherein at least one of the mach-zehnder interferometers is configured to flatten a passband.