On-chip erbium-doped lithium niobate microring lasers

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. A light source, as an essential component for an integrated optical system, is urgently needed. In this Letter, 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 1 million at ∼ 970 n m , 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 µ W and stable performance under the pump of a 980 nm band continuous laser. Comb-like laser spectra spanning from 1510 to 1580 nm were observed in a high pump power regime, which lays the foundation of the realization of pulsed laser and frequency combs on a rare-earth ion-doped LNOI platform. This Letter effectively promotes the development of on-chip integrated active LNOI devices.

Efficient Second Harmonic Generation in a Reverse‐Polarization Dual‐Layer Crystalline Thin Film Nanophotonic Waveguide

“…[15][16][17][18][19][20][21] Recently, thin film crystalline LiNbO 3 (with a typical thickness of 300-900 nm) offers a unique platform to implement on-chip integration of various devices with outstanding performance. [22][23][24][25][26][27][28] The further processing of LNOI wafers enables the construction of nanophotonic waveguides with tightly confined modal fields, in which the interaction of optical waves is significantly enhanced accordingly. Highly efficient nonlinear optical conversion processes have been demonstrated within nanophotonic devices with compact footprints, e.g., loaded waveguide, [29] ridge waveguide, [30][31][32][33][34][35][36] and microring/disk resonators.…”

Integrated Photonics Based on Rare‐Earth Ion‐Doped Thin‐Film Lithium Niobate

“…In a subsequent study by Luo et al more recently, C-band laser emission based on an Er:LNOI on-chip microring, instead of microdisks, is reported. [130] In comparison, microring configuration has better stability and scalability than that of microdisk design (usually with a wet-etched pillar-shaped pedestal underneath) because the optical coupler in the former case is usually an on-chip bus waveguide. Despite the coupling strength between the bus waveguide and the micro-ring is difficult to be flexibly adjusted, such a coupling strategy is more compatible with integrated photonics.…”

Graphical Direct-Writing of Macroscale Domain Structures with Nanoscale Spatial Resolution in Non-Polar-Cut Lithium Niobate on Insulators

“…Lithium niobate (LN) crystal is of excellent electrooptic, pyroelectric, piezoelectric, acousto-optic and nonlinear optical properties, especially with the mature of the fabrication technique of lithium niobate on insulators (LNOI) [1][2][3][4][5], providing a golden material platform for various ferroelectric, opto-electronic and nonlinear optical applications such as ferroelectric and holographic memories [6][7][8], electro-optic modulator [9][10][11], optical waveguide and integrated optics [4,12], and nonlinear optical frequency conversion [13][14][15][16][17], to just mention a few. The ferroelectric LN crystal is of 180 o domain structure, and its ferroelectric domain can be inverted and designed to improve the device performance, for example, the nonlinear optical frequency conversion efficiency can be improved through periodically poled LN (PPLN) based on quasi-phase-matching technique [18,19].…”