Diffraction limited 195-W continuous wave laser emission at 2.09 µm from a Tm³⁺, Ho³⁺-codoped single-oscillator monolithic fiber laser

Abstract

We present a bi-directionally 793-nm diode-pumped Tm3+, Ho3+-codoped silica polarization maintaining double-clad all-fiber laser based on a single-oscillator architecture emitting 195 W at 2.09 µm in continuous wave mode of operation, with a beam quality near the diffraction limit (M2 = 1.08). The power scaling of the laser is only pump-power-limited in the range of the total available pump power (540 W).

High efficiency holmium-doped triple-clad fiber laser at 2120 nm

“…However for laser emission beyond 2.1 µm, the power of this type of fiber source might be limited by the thermal load caused by the exothermic crossrelaxation pumping process [3]. Another approach, similar to the ubiquitous erbium:ytterbium codoped fibers, consists in adding Tm sensitizing ions in an holmium (Ho) doped fiber [4], [5]. The downside of this approach lies mainly in the difficulty of optimizing simultaneously the two dopant concentrations, and in managing the thermal load.…”

“…However for laser emission beyond 2.1 µm, the power of this type of fiber source might be limited by the thermal load caused by the exothermic crossrelaxation pumping process [3]. Another approach, similar to the ubiquitous erbium:ytterbium codoped fibers, consists in adding Tm sensitizing ions in an holmium (Ho) doped fiber [4], [5]. The downside of this approach lies mainly in Bastien Beaumont is with the Office National d'Etudes et de Recherches Aérospatiales (ONERA) in Palaiseau, France and with the iXblue Photonics Division in Lannion, France Pierre Bourdon and Julien Le Gouët are with the Office National d'Etudes et de Recherches Aérospatiales (ONERA) in Palaiseau, France Alexandre Barnini, Louanne Kervella and Thierry Robin are with iXblue Photonics in Lannion, France e-mail: julien.le_gouet@onera.fr.…”

Functional Fibers and Functional Fiber-Based Components for High-Power Lasers

“…On the basis of cladding-pump technology, high-power multimode LDs at 790 nm and highly Tm-doped fibers, the output power of HPFLs exploiting Tm-doped fibers has exceeded the power level of Er-doped fibers gradually and a kilowatt-level output [102] has been achieved as early as 2010, representing the highest CW output power produced by Tm-doped fiber reported publicly currently. In 2018, a Tm-doped chirped pulse amplifier system with a record average power of up to 1150 W and the peak power of more than 5 GW was demonstrated, which brings exciting prospects for [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63], c all-fiber laser amplifiers operating at ~ 1 μm [13, 14, 16-19, 35, 64-83], d all-fiber Er-doped lasers and Er-Ybco-doped lasers operating at ~ 1.5 μm , e all-fiber Tm-doped lasers operating at ~ 2 μm [94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111][112][113]. f Emission cross sections of Er 3+ , Ho 3+ and Dy 3+ ions in mid-infrared waveband [114].…”

Free-running and imposed-wavelength cavities for high power continuous-wave Tm3+, Ho3+ codoped single-oscillator fiber laser

“…The laser setup (Fig. 1a) consisted of a 10-m long double-clad polarization-maintaining thulium-holmium doped fiber (THDF), described in [2], with a Tm/Ho concentration ratio of 10 that permits a good energy transfer from Tm 3+ to Ho 3+ ions [3]. Four high-power 793-nm fiber-coupled laser diodes (LDs) were fusion spliced to two 2+1×1 fiber pump combiners (PCs) to symmetrically pump the THDF, with a total pump power of 540 W. The laser operated in two different cavity architectures: (i) the first one was a free-running cavity, with 4-% Fresnel reflection (FR) on both PCs passive fiber (PAS) cleaved at 0°; (ii) in the second architecture, the cavity was formed by a high reflectivity (HR) fiber Bragg grating (FBG) at 2.09 µm and a passive fiber cleaved at 0° as output coupler (OC).…”