A single-frequency single-resonator laser on erbium-doped lithium niobate on insulator

TL;DR

This paper demonstrates a single-frequency, single-mode Er:LNOI microring laser with high side-mode suppression and narrow linewidth, achieved through mode-dependent loss and gain competition, advancing integrated photonic laser technology.

Contribution

It introduces a method to achieve single-frequency, single-mode lasing in a multi-mode Er:LNOI microring using mode-dependent loss and gain competition.

Findings

Single-mode lasing with 2.1 microwatt output power

Side-mode suppression of 35.5 dB

Linewidth of 1.27 MHz

Abstract

Erbium-doped lithium niobate on insulator (Er:LNOI) is a promising platform for photonic integrated circuits as it adds gain to the LNOI system and enables on-chip lasers and amplifiers. A challenge for Er:LNOI laser is to increase its output power while maintaining single-frequency and single (-transverse)-mode operation. In this work, we demonstrate that single-frequency and single-mode operation can be achieved even in a single multi-mode Er:LNOI microring by introducing mode-dependent loss and gain competition. In a single microring with a free spectral range of 192 GHz, we have achieved single-mode lasing with an output power of 2.1 microwatt, a side-mode suppression of 35.5 dB, and a linewidth of 1.27 MHz.