On-chip erbium-doped lithium niobate microring lasers

TL;DR

This paper reports on the development of on-chip erbium-doped lithium niobate microring lasers operating at 1550 nm with high quality factors, low pump threshold, and stable performance, advancing integrated optical sources.

Contribution

It demonstrates the fabrication and operation of high-Q erbium-doped lithium niobate microlasers on LNOI platform with novel spectral properties and low power thresholds.

Findings

Loaded quality factors > 1 million

Low pump threshold of ~20 μW

Broad laser spectra from 1510 nm to 1580 nm

Abstract

Lithium niobate on insulator (LNOI), regarded as an important candidate platform for optical integration due to its excellent nonlinear, electro-optic and other physical properties, has become a research hotspot. Light source, as an essential component for integrated optical system, is urgently needed. In this paper, we reported the realization of 1550-nm band on-chip LNOI microlasers based on erbium-doped LNOI ring cavities with loaded quality factors higher than one million, which were fabricated by using electron beam lithography and inductively coupled plasma reactive ion etching processes. These microlasers demonstrated a low pump threshold of ~20 {\mu}W and stable performance under the pump of a 980-nm band continuous laser. Comb-like laser spectra spanning from 1510 nm to 1580 nm were observed in high pump power regime, which lays the foundation of the realization of pulsed laser and frequency combs on rare-earth ion doped LNOI platform. This work has effectively promoted the development of on-chip integrated active LNOI devices.