Chirped pulse waveguide amplifier

TL;DR

This paper presents a novel ultrafast Cr:ZnS waveguide amplifier with high gain and power, fabricated via ultrafast laser writing, and optimized through an analytical model for broadband pulse amplification.

Contribution

It introduces a flexible, single-mode Cr:ZnS waveguide amplifier with high gain and power, and provides an analytical model for design optimization.

Findings

Achieved 5.5 dB/cm gain and 2.35 W output power.

Demonstrated broadband amplification over 34 mm length.

Validated the design with an analytical model.

Abstract

We introduce a single-mode Cr:ZnS crystalline waveguide ultrafast amplifier that provides a high gain of 5.5 dB/cm and 2.35 W of average output power. The depressed-cladding buried waveguide is produced by an ultrafast laser writing procedure, which allows a high degree of flexibility in fabrication when the geometry, size, and even effective index can be modified along the waveguide. An analytical model that includes both, pump and pulse propagation, allows calculation and optimization of the waveguide design. In a CPA arrangement with a volume Bragg grating-based stretcher/compressor, we demonstrate a broadband 34-mm long amplifier in a polycrystalline Cr:ZnS with a single-pass gain factor of 75 (5.5 dB/cm) and a high average output power up to 2.35 W.