On-chip ultra-narrow-linewidth single-mode microlaser on lithium niobate on insulator

TL;DR

This paper presents a low-threshold, ultra-narrow-linewidth single-mode microlaser on lithium niobate on insulator, demonstrating significant advancements in on-chip laser performance with potential photonic applications.

Contribution

It introduces a novel on-chip single-mode microlaser with ultra-narrow linewidth and low threshold, fabricated on Erbium-doped lithium niobate on insulator, utilizing Vernier effect in a photonic molecule.

Findings

Threshold pump power as low as 200 μW

Linewidth of 4 kHz achieved, the best in LNOI microlasers

Single mode emission at 1550.5 nm

Abstract

We report an on-chip single mode microlaser with low-threshold fabricated on Erbium doped lithium niobate on insulator (LNOI). The single mode laser emission at 1550.5 nm wavelength is generated in a coupled photonic molecule, which is facilitated by Vernier effect when pumping the photonic molecule at 970 nm. A threshold pump power as low as 200 uW is demonstrated thanks to the high quality factor above 10^6. Moreover, the linewidth of the microlaser reaches 4 kHz, which is the best result in LNOI microlasers. Such single mode micro-laser lithographically fabricated on chip is highly in demand by photonic community.