High-power widely tunable thulium fiber lasers
TL;DR: Two different laser configurations for high-power tunable thulium fiber lasers are reported on: one is a single oscillator utilizing a volume Bragg grating for wavelength stabilization; the other is a master oscillator power amplifier system with the oscillator stabilized and made tunable by a diffraction grating.
Abstract: Applications requiring long-range atmospheric propagation are driving the development of high-power thulium fiber lasers. We report on the performance of two different laser configurations for high-power tunable thulium fiber lasers: one is a single oscillator utilizing a volume Bragg grating for wavelength stabilization; the other is a master oscillator power amplifier system with the oscillator stabilized and made tunable by a diffraction grating. Each configuration provides >150W of average power, >50% slope efficiency, narrow output linewidth, and >100nm tunability in the wavelength range around 2μm.
Citations
More filters
TL;DR: Recent advances of high-power continuous wave, Q-switched, mode-locked, and single-frequency fiber lasers in the 1, 1.5, 2, and 3 μm regions and their applications in such areas as industry, medicine, research, defense, and security are addressed in detail.
Abstract: Fiber lasers have seen progressive developments in terms of spectral coverage and linewidth, output power, pulse energy, and ultrashort pulse width since the first demonstration of a glass fiber laser in 1964. Their applications have extended into a variety of fields accordingly. In this paper, the milestones of glass fiber laser development are briefly reviewed and recent advances of high-power continuous wave, Q-switched, mode-locked, and single-frequency fiber lasers in the 1, 1.5, 2, and 3 μm regions and their applications in such areas as industry, medicine, research, defense, and security are addressed in detail.
318 citations
TL;DR: In this paper, the relationship between the laser process conditions and the dimensions and quality of the seam was investigated by means of optical and phase-contrast microscopy, which revealed a tensile strength of greater than 80% of the bulk material strength.
Abstract: Absorber-free transmission and butt-welding of different polymers were performed using thulium fiber laser radiation at the wavelength 2 μm. The relations between the laser process conditions and the dimensions and quality of the seam were investigated by means of optical and phase-contrast microscopy. Mechanical properties of the weld joints were studied in tensile strength tests. Laser-welded polyethylene samples revealed a tensile strength of greater than 80% of the bulk material strength. Transmission welding of different polymer combinations featured the formation of different joint classes depending on the spectral properties. The experiments demonstrate new application areas of mid-IR fiber laser sources for materials processing.
256 citations
Cites methods from "High-power widely tunable thulium f..."
...A x.doi.org/10.1016/j.optlastec.2012.03.020 esponding author. ail address: mingareev@ucf.edu (I. Mingareev a b s t r a c t Absorber-free transmission and butt-welding of different polymers were performed using thulium fiber laser radiation at the wavelength 2 mm....
[...]
TL;DR: The relevance of the material in high power fiber laser technologies is reviewed, and where appropriate, materials-based paths to the enhancement of laser performance will be underscored.
Abstract: Over the past two decades, fiber laser technologies have matured to such an extent that they have captured a large portion of the commercial laser marketplace. Yet, there still is a seemingly unquenchable thirst for ever greater optical power to levels where certain deleterious light-matter interactions that limit continued power scaling become significant. In the past decade or so, the industry has focused mainly on waveguide engineering to overcome many of these hurdles. However, there is an emerging body of work emphasizing the enabling role of the material. In an effort to underpin these developments, this paper reviews the relevance of the material in high power fiber laser technologies. As the durable material-of-choice for the application, the discussion will mainly be limited to silicate host glasses. The discussion presented herein follows an outward path, starting with the trivalent rare earth ions and their spectroscopic properties. The ion then is placed into a host, whose impact on the spectroscopy is reviewed. Finally, adverse interactions between the laser lightwave and the host are discussed, and novel composition glass fiber design and fabrication methodologies are presented. With deference to the symbiosis required between material and waveguide engineering in active fiber development, this review will emphasize the former. Specifically, where appropriate, materials-based paths to the enhancement of laser performance will be underscored.
138 citations
TL;DR: In this paper, the state-of-the-art in sources of coherent, pulsed mid-IR radiation is reviewed, and the main part of the review is focused on midIR generation and amplification based on parametric frequency conversion, enabling highest midIR peak power pulses.
95 citations
TL;DR: In this article, the authors present a review of holmium-doped silica fiber-based sources and discuss the future development potential of sources in the ns-fs pulse-width range.
93 citations
References
More filters
TL;DR: In this paper, the spectral properties of fiber reflection and transmission gratings are described and examples are given to illustrate the wide variety of optical properties that are possible in fiber gratings.
Abstract: In this paper, we describe the spectral characteristics that can be achieved in fiber reflection (Bragg) and transmission gratings. Both principles for understanding and tools for designing fiber gratings are emphasized. Examples are given to illustrate the wide variety of optical properties that are possible in fiber gratings. The types of gratings considered include uniform, apodized, chirped, discrete phase-shifted, and superstructure gratings; short-period and long-period gratings; symmetric and tilted gratings; and cladding-mode and radiation-mode coupling gratings.
3,330 citations
"High-power widely tunable thulium f..." refers background in this paper
...Fiber Bragg gratings (FBGs) are often used for spectral selection in fiber lasers [12], but there are difficulties achieving subnm spectral widths particularly in combination with large mode area (LMA) fibers [13], and the tuning range of FBGs is limited by the mechanical strength of the fiber typically to a few tens of nanometers [14]....
[...]
TL;DR: Broadly tunable cw laser emission is reported in Tm:YAG and TM:YSGG at room temperature with Ti:sapphire laser pumping with smooth tuning results from overlapping transitions between phonon-broadened crystal field Stark levels.
Abstract: Broadly tunable cw laser emission is reported in Tm:YAG and Tm:YSGG at room temperature with Ti:sapphire laser pumping. The Tm3+3F4 → 3H6 transition is tuned continuously over the ranges 1.87–2.16 μm in YAG and 1.85–2.14 μm in YSGG. Smooth tuning results from overlapping transitions between phonon-broadened crystal field Stark levels.
299 citations
TL;DR: Bragg diffractive gratings recorded in the volume of photosensitive silicate glasses doped with silver, cerium, fluorine, and bromine recorded with photothermorefractive process observedabsolute diffraction efficiency of as much as 93% was observed for 1-mm-thick gratings with spatial frequencies up to 2500 mm(-1).
Abstract: Photosensitive silicate glasses doped with silver, cerium,
fluorine, and bromine were fabricated at the Center for Research and
Education in Optics and Lasers. Bragg diffractive gratings were
recorded in the volume of these glasses with a photothermorefractive
process (exposure to UV radiation of a He–Cd laser at 325 nm is
followed by thermal development at 520 °C). Absolute
diffraction efficiency of as much as 93% was observed for 1-mm-thick
gratings with spatial frequencies up to 2500 mm-1. No
decreasing of diffraction efficiency was detected at low spatial
frequencies. Original glasses were transparent (absorption
coefficient less than 1 cm-1) from 350 to 4100
nm. Induced losses in exposed and developed glass decreased from
0.3 to 0.03 cm-1 between 400 and 700 nm, respectively, and
did not exceed 0.01–0.02 cm-1 in the IR region from 700
to 2500 nm. Additional losses caused by parasitic structures
recorded in the photosensitive medium were studied.
288 citations
Journal Article•
TL;DR: In this paper, the Tm3+3F4 → 3H6 transition is tuned continuously over the ranges 1.87-2.16 μm in YAG and 1.85- 2.14 μm on YSGG.
Abstract: Broadly tunable cw laser emission is reported in Tm:YAG and Tm:YSGG at room temperature with Ti:sapphire laser pumping. The Tm3+3F4 → 3H6 transition is tuned continuously over the ranges 1.87–2.16 μm in YAG and 1.85–2.14 μm in YSGG. Smooth tuning results from overlapping transitions between phonon-broadened crystal field Stark levels.
284 citations
TL;DR: In this paper, the authors identify the cross relaxation (CR) and energy transfer upconversion (ETU) processes that are important to the operation of Tm 3+ -doped silica fiber lasers using the slope efficiency measured from a number of diode-pumped Tm3+-doped laser arrays.
269 citations
"High-power widely tunable thulium f..." refers background in this paper
...Thulium-doped silica fiber lasers take advantage of the well-known cross relaxation process that allows an ∼80% theoretical slope efficiency when pumping with 792 nm diodes [7,8], and >70% slope efficiencies have been realized experimentally [9]....
[...]
...The active fiber is wrapped around an 11 cm diameter mandrel that is cooled to ∼14 °C to promote efficient two-for-one cross relaxation [8]....
[...]