We present a tunable, high power cladding-pumped holmium doped fiber laser. The laser generated >15 W CW average across wavelength range of 2.043 - 2.171 μm, with maximum output 29.7 at 2.120 μm. also produced 18.2 when operating µm. To the best our knowledge this is highest operation >2.15 discuss significance background losses and design for achieving efficient in fibers.

We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass utilises fluorine doped glass layer to provide low loss guidance 1.95 µm pump radiation. both single mode and large-mode area lasers was demonstrated, with up 140 W output achieved. A slope efficiency 59% versus launched demonstrated. free running emission measured be 2.12-2.15 demonstrating potential this architecture address long wavelength based high efficiency.

We present a single-mode, monolithic holmium-doped silica fibre laser resonantly pumped by thulium-doped lasers through fused pump combiner. report the highest achieved output power for holmium of 407 W.

A theoretical model to describe in-band pumped holmium doped silica fiber lasers is presented. The established based upon theory and parameters obtained from published research works. Both core-pumped system cladding-pumped are simulated with the model. simulation results agree well most experimental results, for cases in which show discrepancy disagreement can be reasonably explained. Through numerical analysis it found that besides common negative factors such as non-radiative decay, loss,...

We present a novel large-mode-area thulium-doped fibre with large pedestal design. discuss the advantages of this in context overcoming limitations imposed by cleaving and splicing tolerances. Finally we demonstrate use such constructing monolithic lasers operating at 1.95 µm 170 W output power, 0.1 nm line-width diffraction limited beam quality M(2)(X,Y) = 1.02, 1.03.

We report the highest power operation of a monolithic polarised gain-switched holmium fiber laser. In this paper we describe pulsed two lasers, which were by thulium The first laser produced pulses with minimum pulse duration 85 ns, maximum energy 16 µJ and repetition rate 600 kHz. This was linearly an extinction ratio >18.5 dB under all operating conditions achieved average powers up to 5.1 W at 2.104 µm. second demonstrated shorter 38 ns 300 1.5 2.112

The resonant pumping of holmium fibre lasers provides a laser platform capable addressing wide range applications that benefit from operation at wavelengths beyond 2.1 μm. This architecture can provide devices promise high efficiency sources in the μm spectral region with excellent beam quality and power scalability. paper presents our recent results resonantly pumped pulsed CW lasers. We have demonstrated first efficient cladding-pumped source. investigated both single mode large area...

We present the design of a polarisation maintaining, resonantly and cladding pumped, large mode area holmium-doped fibre. describe operation this fibre in pulsed amplifier configuration. The produced pulses with energy 2.25 mJ duration 20 ns at repetition rate kHz average power 45 W. provided >10 dB gain 2.09 µm extinction ratio was >11.5 dB. beam quality output (M2) 1.6. To best our knowledge is highest pulse achieved from any singly by an order magnitude.

We present a single-mode, 2.09 μm holmium-doped silica fibre laser resonantly pumped by 1.95 thulium-doped laser. The slope efficiency of 87% versus absorbed power is to our knowledge the highest reported date.

Tm-doped 790-nm-pumped silica fiber lasers are excellent candidates for producing emission at <1.95 microm, but achieving efficient operation these wavelengths requires careful attention to design because of the characteristic three-level reabsorption effects. We present a discussion methods mitigation effects and two high-efficiency systems that capable up 70 W <1.92 microm.

Resonantly pumped holmium fibre lasers present a range of opportunities for the development novel laser and amplifier devices due to availability mature, efficient high power thulium pump lasers. In this paper we describe operation large mode area holmium-doped amplifier. The master-oscillator is an all-fibre linearly polarised, core single operating at 27 W 2.11 μm. This was amplified in producing up 265 output power. system first demonstration resonantly holmiumdoped It also highest that...

Abstract Additive manufacturing (AM) is recognized as a transformative approach to prototyping and by all sectors of industry, especially the aerospace which has lead adoption AM for critical end use parts. In academia, also received great deal interest vehicle improve design education facilitate student innovation. The objective this effort readiness diversity engineering workforce in experiencing scarcity talent. We engaged multidisciplinary team minority students manufacture modular...

In this paper we review the damage mechanisms that need to be considered when building high power fibre lasers. More specifically look at thermal issues, optically induced coating damage, bulk and surface thresholds of host glass. We also discuss reliability tapered bundles Bragg gratings these densities.

Here we report a compact monolithic 2000nm pulsed laser with single spatial mode output, ~1.5ns pulse duration, 8kW peak power and >200mW average at 20 kHz repetition rate. The gain-switched laser, consisting of pair fiber Bragg gratings 0.5m thulium-doped cladding fiber, was core pumped by high 1.5μm laser. When the input energy pump pulses sufficient enough to saturate Thulium doped stable train observed measured linewidth 0.05nm which corresponds limit resolution for Optical Spectrum...

Continued recent developments in Thulium- (Tm) doped silica fiber design have enabled average power scaling of 2 µm laser system beyond the kW-level. One approach to furthering this development is maximize slope efficiency Tm-doped lasers by selecting highly-doped double-clad fibers (TDF's) so as promote cross-relaxation process. The success was exemplified Tumminelli et al. who employed an all-halide vapor-phase fabrication process produce a single-mode (SM) with Tm concentration 8.5 wt%...

The advent of double clad fiber technology has made high power lasers and amplifiers possible. However, the scalability output powers can be limited by amplified spontaneous emission nonlinear processes such as stimulated Raman scattering (SRS) Brillouin (SBS). These limitations overcome using low numerical apertures (NAs), large-mode areas (LMAs), novel index profiles dopant concentrations. This paper discusses advances in design fabrication highly efficient, area fibers. Experimental...

Single mode, single-polarization output is demonstrated in a large mode area (LMA) fiber laser. Both filtering and polarization are by simply coiling multimode Polarization Maintaining Fibers (PMFs). The extinction ratio improved increasing the birefringence of fiber. design scaleable for all-fiber high power lasers.

CO₂ and YAG lasers are routinely capable of producing cw output powers in the range sub-W to multi-kW as such have become mainstay laser cutting welding industry. Despite numerous advancements their design, these still typified by poor wallplug efficiencies (typically 1-10%) and/or relatively optical beam qualities. On other hand, recent developments diode technology, fiber design combining techniques meant that cladding pumped ytterbium-doped attracted growing interest a route...

Power scaling of single mode Yb‐doped fiber lasers operating at around 1064 nm has now reached the 10 kW level making it suitable for a variety high power industrial material processing applications1）. However, progress on narrow linewidth, frequency amplifiers been much slower because fundamental limitations from non-linearities such as stimulated Brillouin scattering (SBS) in optical fiber. In this paper we discuss physics SBS, and amplifier designs that overcome limitation through...

Fibers for high-power laser and amplifier applications require large claddings with high numerical apertures efficiently coupling pump energy. In addition, such fibers should have rare-earth dopant concentrations in relatively cores, low apertures, to reduce non-linearities. Furthermore, polarization maintaining double-clad (PM-DCF) are needed coherently combining the outputs of several lasers/amplifiers achieve output powers excess 100 kW military industrial applications. this paper, we...

We report on a very highly doped and efficient cladding pumped single mode Tm3+ silica fiber laser operating at 1.985 microns. The preform was fabricated using proprietary all halide vapor phase modification of the MCVD process. core has maximum Tm2O3 doping concentration greater than 8.5 wt%. A based resulting double clad 793 nm demonstrated record slope efficiency 74.5 % wrt absorbed pump power.

Sources based on resonantly cladding pumped holmium-doped fibres have been demonstrated at >400 W CW or with pulse energies of >2 mJ. We review the enabling technologies, and discuss challenges associated high power operation fibre lasers 2.1 μm.

Holmium-doped fibres provide a power scalable gain-medium capable of operation at wavelengths beyond 2.05 μm. We discuss and review our approach to the scaling pulsed CW laser sources 2.1 μm using holmium-doped fibres. This paper outlines experiments which demonstrate wavelength region accessible silica fibres, as well linearly polarised master-oscillator amplifier high average systems. These devices applicability holmium fibre lasers range scientific, medical, industrial defence applications.