Single-frequency Er³⁺ doped phosphate fiber MOPA

authored by

Phillip Booker, Marian Dürbeck, Nadia G. Boetti, Diego Pugliese, Silvio Abrate, Daniel Milanese, Michael Steinke, Jörg Neumann, Dietmar Kracht

Abstract

Single-frequency Er³⁺ doped fiber amplifiers in MOPA configuration are promising candidates to fulfil the challenging requirements of laser sources at 1.5 μm for the third generation of interferometrie gravitational wave detectors (GWDs) [1]. An all-fiber design ensures excellent beam quality, stability and reliability compared to bulk concepts. However, in monolithic systems high power operation gives rise to non-linear effects such as stimulated Brillouin scattering (SBS), which eventually limit the output capacity of such fiber MOPAs [2]. Since the threshold power for SBS scales inversely with the length and cross-section of the fiber, researchers placed much attention to enhance the Er³⁺ doping levels and therefore decrease necessary fiber length for sufficient signal amplification. However, already at moderately low doping concentrations Er³⁺ ions tend to form clusters in industry-standard fused silica fibers. Consequently, the short intra-cluster distances between adjacent Er³⁺ ions introduce quenching effects in terms of homogenous up-conversion processes (I_13/2 + I_13/2 → I_9/2 + I_15/2). Thus, high inversion levels can reduce the pump-to-signal energy conversion efficiency and amplifier's output capacity since ions in the I_9/2 state relax non-radiatively.

External Organisation(s)

Laser Zentrum Hannover e.V. (LZH)
LINKS Foundation
Politecnico di Torino (POLITO)

Type

Conference contribution

Publication date

2019

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Spectroscopy, Electronic, Optical and Magnetic Materials, Instrumentation, Atomic and Molecular Physics, and Optics, Computer Networks and Communications

Electronic version(s)

https://doi.org/10.1109/cleoe-eqec.2019.8871636 (Access: Closed)