Patent ID: 8326154

Claim:
A multiwavelength transmitter comprising: a plurality of laser sources each configured to generate light of a different wavelength; a first wavelength selective filter arranged to direct light from each of the laser sources into a first waveguide; a plurality of optical modulators each arranged to modulate light at one of the said wavelengths with a respective data signal; a second wavelength selective filter arranged to direct each of said different wavelengths of light from the first waveguide to a respective one of the optical modulators; and an output waveguide arranged to receive the modulated light from each of the optical modulators, and wherein the laser sources each comprise a respective optical gain block and the laser sources share a common cavity reflector, and the first wavelength selective filter is located in the optical path between the optical gain blocks and the common cavity reflector, and wherein the common cavity reflector is configured to direct wavelengths either directly out of the laser cavity or out of the laser cavity via a coupler.