Widely and fast tunable external cavity laser on the thin film lithium niobate platform

We develop an integrated external cavity laser with a broad wavelength tuning range and a fast switching speed on thin film lithium niobate (TFLN) platform. By butt coupling an InP-based optical gain chip with a TFLN external cavity chip, a hybrid lithium niobate/III-V tunable laser with a wavelength switching speed of 18 ns is achieved. Furthermore, using a cascaded external cavity filter composed of three micro-ring resonators (MRRs), the laser features an ultra-wide wavelength tuning range of 96 nm across the C + L + U bands, which is the greatest value known for tunable lasers integrated on TFLN. The maximum laser output power is 0.98 mW, with a measured side mode suppression ratio (SMSR) of better than 52 dB. The laser we developed is critical in applications such as optical sensors and wavelength routed optical switch. © 2023 xxxxxxxx. Hosting by Elsevier B.V. All rights reserved.