High power, continuous-wave, single frequency fiber amplifier at 1091 nm and frequency doubling to 545.5 nm

TL;DR

This paper reports a high power, single-frequency fiber amplifier at 1091 nm producing 30 W, with efficient suppression of spontaneous emission, and compares two methods of frequency doubling to generate 545.5 nm light.

Contribution

The paper introduces a high power ytterbium fiber amplifier with improved suppression and compares two effective frequency doubling techniques for visible light generation.

Findings

Achieved 30 W output at 1091 nm with >40 dB suppression of spontaneous emission.

Generated up to 19.3 W at 545.5 nm using external enhancement cavity with LBO.

Demonstrated efficient frequency doubling methods for high power laser applications.

Abstract

We present a high power single-frequency ytterbium fiber amplifier system with an output power of 30 W at 1091 nm. The amplifier system consists of two stages, a preamplifier stage in which amplified spontaneous emission is efficiently suppressed (>40 dB) and a high power amplifier with an efficiency of 52 %. Two different approaches of frequency doubling are compared. We achieve 8.6 W at 545.5 nm by single-pass frequency doubling in a MgO-doped periodically poled stoichiometric LiTaO3 and up to 19.3 W at 545.5 nm by frequency doubling with a lithium-triborate (LBO) crystal in an external enhancement cavity.