High-power continuous-wave Tm³⁺:Ho³⁺-codoped fiber laser operation from 2.1 µm to 2.2 µm

Abstract

A Tm3+:Ho3+-codoped free-space single-oscillator fiber laser is under investigation with special focus on the power scalability of emission wavelengths from 2.1 µm to 2.2 µm. Using a tunable diffraction grating, a 200-nm tunable laser source is built. Laser output powers above 10 W are delivered from 1990 nm up to 2190 nm, demonstrating the range for stable high-power laser operation. By replacing the diffraction grating by a highly reflective, narrow linewidth volume Bragg grating, power scaling is performed at 2.1 µm and is even enabled at a wavelength of 2.2 µm. Using a volume Bragg grating (VBG) at 2.1 µm, a slope efficiency of 49% is measured with an output power of 262 W. Using another VBG with a center wavelength of 2.2 µm, the fiber laser delivers a record power of 77 W with a slope efficiency of 29%.

12.2 W ZGP OPO pumped by a Q-Switched Tm3+:Ho3+-codoped fiber laser

“…The laser achieves a slope efficiency of 34.5 %, reaching an output power of 51 W when pumped with 167 W at 793 nm. The achieved slope efficiency of 34.5 % -compared to the almost 50 % slope efficiency reported in literature for longer fiber lengths 4 -indicates that optimizing the laser for efficient nonlinear conversion involves some trade-offs.…”

“…Tm 3+ :Ho 3+ -codoped fiber lasers have shown to efficiently address the long-wavelenth ranging from 2.1 µm to 2.2 µm. 4 Secondly, the laser architecture has undergone significant evolution. Early MWIR OPOs were pumped by master oscillator power amplifier (MOPA) systems, which were seeded by Qswitched fiber lasers.…”

Dual-wavelength fiber lasers based on active fibers with structured cores

“…Fiber lasers, though born at almost the same time as groundbreaking inventions of laser and single-mode optical fiber in sixties, have been waiting for to their golden times several decades [1][2][3] and now they outperform other laser sources by high brightness and beam quality, efficient pumping, enhanced cooling, and compactness [4][5][6][7][8]. Despite the rapid progress of fiber laser technology, especially in the new millennium, many issues have to be resolved and new fiber designs are investigated.…”

Passive Fiber with Pedestal in a 213-W Continuous Wave Monolithic Tm3+-Doped Fiber Laser at 1.94 µm

“…Motard et al reported 195 W of output power at 2.09 µm and 44.8 % of slope efficiency at the output of a monolithic single-oscillator codoped fiber laser source [1]. With a free-space pumping system, Forster et al reported a maximum output power of 262 W at 2.1 µm and a slope efficiency of 49 % [2]. Another solution is to pump directly a Ho 3+ -doped fiber with a Tm 3+ -doped fiber laser.…”