A 10-kHz intrinsic linewidth coupled extended-cavity DBR laser monolithically integrated on an InP platform
Rakesh Ranjan Kumar, Andreas Hänsel, Mónica Far Brusatori, Lars Nielsen, Luc M. Augustin, Nicolas Volet, Martijn J. R. Heck
Abstract
We report a monolithically integrated coupled extended-cavity distributed Bragg reflector laser with, to our knowledge, the lowest reported intrinsic linewidth of ∼10 kHz, which is extracted from a corresponding frequency-noise level of ∼3200 Hz 2 /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 18 mW around 1550 nm at an injection current of 95 mA. The laser operates in a single-mode regime with a side-mode suppression ratio of 54 dB. Our monolithic approach paves the way toward further integration, such as integrated quantum key distribution transceivers.