Laser system with active wavelength control

Abstract

Described herein are packages and techniques aimed at stabilizing the wavelengths of emission of a wavelength division multiplexing (WDM) optical source against temperature fluctuations. An optical source is coupled with a feedback loop that monitors the degree to which the wavelengths of emission conform to the designated WDM channel grid and dynamically adjusts the operating parameters of the source to maintain such conformity. The technique involves a combination of coarse spectral alignment and fine spectral alignment. An optical source uses a pair of thermo-electric coolers (TEC) to aid in the spectral alignment process. A first TEC is thermally coupled to a laser chip. A second TEC is thermally coupled to a multiplexer chip – a chip that monitors compliance of the emission wavelengths with the designated WDM grid.