On-Chip Neodymium-Doped Lithium Niobate Microdisk Laser with Self-Induced Pulsing

TL;DR

This paper reports the first on-chip Nd-doped lithium niobate microdisk laser, achieving lasing at 1094 nm with self-induced pulsing due to nonlinear dynamics, advancing integrated photonic laser technology.

Contribution

It demonstrates the first integrated Nd:LNOI microdisk laser with continuous-wave and pulsed operation, revealing new nonlinear dynamical behaviors in on-chip lasers.

Findings

Lasing at 1094.17 nm with low threshold of 146 μW

Observation of self-induced pulsing with 500 μs pulse duration

Stable CW and pulsed lasing within a monolithic Nd:LNOI cavity

Abstract

Rare-earth-doped materials constitute the foundation of conventional solid-state lasers, but their bulk-crystal form is inherently incompatible with photonic integration, making it challenging to realize compact, high performance nanoscale laser sources. Lithium niobate on insulator (LNOI), with its exceptional electro-optic and nonlinear optical properties, has emerged as one of the most promising platforms for integrated photonics. Combining Nd3+ doping with LNOI offers the unique possibility of uniting the efficient gain provided by Nd3+ ions with the excellent characteristics of LNOI. However, on-chip laser emission from Nd:LNOI has not been demonstrated previously. In this work, we report the first realization of an integrated Nd:LNOI microdisk laser, demonstrating lasing at 1094.17 nm under 785.10 nm pumping with a low threshold of 146 uW and a slope efficiency of 1.962*10^(-5). Beyond continuous-wave operation, we further observe self-induced laser pulsing on the hundred-microsecond scale, with a laser-pulse duration down to 500 us and an oscillation period of 6.45 ms, arising from nonlinear thermo-optic-photorefractive dynamics. We demonstrate stable continuous wave lasing and self-induced pulsed emission within a monolithically integrated Nd:LNOI cavity. Our results expand the operational degrees of freedom for LNOI-based lasers and open a new direction toward deeply integrated gain with intrinsic nonlinear dynamical processes.