ABSTRACT
We report a monolithically integrated coupled extended-cavity distributed Bragg reflector laser with, to our knowledge, the lowest reported intrinsic linewidth of â¼10 kHz, which is extracted from a corresponding frequency-noise level of â¼3200 Hz2/Hz, realized on an InP generic foundry platform. Using the delayed self-heterodyne method, the experimentally measured linewidth was 45 kHz. The laser has an on-chip optical output power of 18â mW around 1550â nm at an injection current of 95â mA. The laser operates in a single-mode regime with a side-mode suppression ratio of 54â dB. Our monolithic approach paves the way toward further integration, such as integrated quantum key distribution transceivers.
ABSTRACT
We present a wavelength tunable, coupled-cavity laser in a standard indium phosphide multiproject wafer shuttle which did not support distributed feedback gratings. The single-mode operation was enabled by reflections from slots in the laser cavity. The wavelength of the laser emission was tunable over 20 nm near a wavelength of 1560 nm via the currents applied to each section of the laser. A maximum side-mode suppression ratio of 46 dB was observed. The delayed self-heterodyne spectrum of the laser showed a Voigt line shape, corresponding to optical linewidths of 3.7 MHz for the Lorentzian and 88 MHz for the Gaussian contributions.