On-chip integrated Yb3+-doped waveguide amplifiers on thin film lithium niobate

TL;DR

This paper reports the fabrication and optical characterization of Yb3+-doped waveguide amplifiers on thin film lithium niobate, demonstrating low loss and measurable gain suitable for integrated photonic applications.

Contribution

It introduces a novel fabrication process for Yb3+-doped lithium niobate waveguides with low propagation loss and measurable gain, advancing integrated photonic amplifier technology.

Findings

Low propagation loss of 0.13 dB/cm at 1030 nm

Internal net gain of 5 dB at 1030 nm and 8 dB at 1060 nm

Gain per unit length of 1.25 dB/cm at 1030 nm and 2 dB/cm at 1060 nm

Abstract

We report the fabrication and optical characterization of Yb3+-doped waveguide amplifiers (YDWA) on the thin film lithium niobate fabricated by photolithography assisted chemo-mechanical etching. The fabricated Yb3+-doped lithium niobate waveguides demonstrates low propagation loss of 0.13 dB/cm at 1030 nm and 0.1 dB/cm at 1060 nm. The internal net gain of 5 dB at 1030 nm and 8 dB at 1060 nm are measured on a 4.0 cm long waveguide pumped by 976nm laser diodes, indicating the gain per unit length of 1.25 dB/cm at 1030 nm and 2 dB/cm at 1060 nm, respectively. The integrated Yb3+-doped lithium niobate waveguide amplifiers will benefit the development of a powerful gain platform and are expected to contribute to the high-density integration of thin film lithium niobate based photonic chip.