Patent ID: 8457165

Claim:
A device for producing laser light at different optical wavelengths, comprising: an array of tunable lasers to produce laser light at different optical wavelengths, respectively, each tunable laser including: a tunable sampled Bragg grating reflector responsive to an electrical control signal to produce tunable reflectivity peaks within a tunable spectral range; a second grating reflector that is spaced from the sampled Bragg grating reflector to form an optical resonator with the sampled Bragg grating reflector and produces reflectivity peaks at different second grating reflector resonance wavelengths within the tunable spectral range of the tunable sampled Bragg grating reflector; and a gain section between the tunable sampled Bragg grating reflector and the second grating reflector, the gain section capable of being electrically energized to produce an optical gain for the laser light at a respective optical wavelength produced by the tunable laser; and a laser control unit electrically coupled to the tunable lasers to apply the electrical control signal as a common control signal to the tunable sampled Bragg grating reflector in each of the tunable lasers to synchronously tune the tunable lasers that operate at the different optical wavelengths, respectively, wherein a sampling period length of the tunable sampled Bragg grating reflector creates a coarse tuning step approximately equal to a number of the tunable lasers in the array of tunable lasers, multiplied by, a channel spacing between the different optical wavelengths of the tunable lasers in the array, the sampling period length configured to reduce optical loss in the tunable lasers.