# Diode-pumped wavelength-switchable quasi-three-level Nd:LiLuF4 laser on the 4F3/2→4I9/2 transition

## TL;DR

This paper introduces a new diode-pumped laser using Nd:LiLuF4 that can switch between single and dual wavelengths without extra losses.

## Contribution

A new method for wavelength-switchable operation in quasi-three-level lasers without intracavity losses is proposed.

## Key findings

- Maximum single-wavelength output power of 4.03 W at 905 nm was achieved.
- Dual-wavelength operation at 905 and 909 nm reached a total output power of 3.21 W.
- Single-wavelength emission at 909 nm achieved 2.21 W output power.

## Abstract

We first demonstrate a continuous-wave (CW) wavelength-switchable quasi-three-level Nd:LiLuF4 laser operating at 4F3/2 → 4I9/2 transition. By shifting the pump beam waist location in the Nd:LLF, switching between single-wavelength (SW) and dual-wavelength (DW) operation can be achieved. The maximum SW output power of 4.03 W at 905 nm was obtained with a slope efficiency of 27.9% relative to the absorbed pump power. Furthermore, DW operation at 905 and 909 nm yielded the highest total output power of 3.21 W. Additionally, SW emission at 909 nm also reached a maximum output power of 2.21 W. Since the switching between SW and DW laser emissions is realized without introducing additional intracavitary losses, the method proposed in this paper provides a new approach for achieving high-power solid-state lasers with wavelength-switchable operation.