# Heat mitigation of a core/cladding Yb-doped fiber amplifier using anti-Stokes fluorescence cooling

## TL;DR

This paper proposes a novel core/cladding Yb-doped fiber amplifier design that uses anti-Stokes fluorescence cooling in both core and cladding to effectively reduce heat in high-power operation, eliminating external cooling needs.

## Contribution

It introduces a new fiber amplifier configuration with anti-Stokes fluorescence cooling in both core and cladding, enhancing heat mitigation in high-power fiber lasers.

## Key findings

- Anti-Stokes fluorescence cooling effectively reduces heat in the fiber.
- The model predicts temperature distribution and heat density in the fiber.
- Cooling is sufficient to eliminate the need for external cooling systems.

## Abstract

A Core/Cladding Yb-doped fiber amplifier configuration is presented that relies on anti-Stokes fluorescence cooling for effective heat mitigation in high-power operation. In the proposed design, the inner cladding of the double clad fiber is doped with the same ion as in the core; therefore, the excess heat generated from the background absorption is removed by the anti-Stokes fluorescence in both core and inner cladding. We consider both silica and ZBLAN glasses for the host material in the Core/Cladding Yb-doped fiber amplifier. The model incorporates the spatial profiles of the signal and pump intensities, as well as the amplified spontaneous emission. The total linear heat density and temperature distribution in the fiber amplifier are calculated. The results show that the anti-Stokes fluorescence cooling in the Core/Cladding Yb-doped configuration can mitigate the generated heat effectively in high-power operation, which obviates the need for an external cooling system.