Patent ID: 7885492

Claim:
A monolithic transmitter photonic integrated circuit (TxPIC) chip comprising: an array of N laser devices, each formed in an optical waveguide of an array of optical waveguides and operating at a different wavelength and providing a respective light output; an array of N electro-optic modulator devices integrated on said chip, one each in an optical waveguide of said waveguide array to receive the respective light output of a laser device to provide a modulated output comprising a channel signal, all of said channel signals together representative of a plurality of wavelengths on a predetermined wavelength grid; an arrayed waveguide grating integrated on said chip, said arrayed waveguide grating coupled to each of said optical waveguides of said waveguide array to receive said channel signals from said modulator devices and combined into a multiplexed channel signal on an optical waveguide output from the chip; characterized by at least one additional set or individual of said devices formed in at least some of said optical waveguides for redundancy so that if one set or individual of said devices fails, another thereof may be utilized in its place.