Dual-wavelength-pumping of mid-infrared Tm:YLF laser at 2.3 µm: demonstration of pump seeding and recycling processes.

Upconversion pumping of thulium lasers emitting around 2.3 µm (the H → H transition) has recently attracted a lot of attention as it is compatible with the mature Yb-laser technology. To explore this possibility, we built a mid-infrared Tm:LiYF laser pumped by an Yb:CaF laser at 1.

Excited-state absorption in thulium-doped materials in the near-infrared.

Excited-state absorption (ESA) is a key process for upconversion pumping schemes of thulium (Tm) doped laser materials. We have systematically studied two ESA transitions in the near-infrared spectral range, namely F → F (at ∼1 µm) and F → H (at ∼1.5 µm), in various Tm-doped fluoride (ZBLAN glass, cubic KYF and CaF, tetragonal LiYF and LiLuF, monoclinic BaYF crystals) and oxide (cubic YAlO, orthorhombic YAlO crystals) laser materials, using a pump-probe method with a polarized light.

Thermal lensing, heat loading and power scaling of mid-infrared Er:CaF lasers.

Mid-infrared Er:CaF laser operating on the I → I transition is developed. Its power scaling capabilities and thermo-optics (fractional heat loading and thermal lensing) are compared under pumping into the I and I states. Using a 4.

Er:KYF laser at 2.80 µm.

We report on the mid-infrared laser operation of a cubic 15 at.% : crystal. In the quasi-continuous-wave regime, the peak power reaches 255 mW at 2.

Watt-level europium laser at 703 nm.

We report on a watt-level highly efficient europium laser operating at the ${^5{\rm D}_0 \to {^7}{\rm F}_4}$ transition. It is based on the stoichiometric ${\rm KEu}{({\rm WO}_4)_2}$ crystal. Under pumping by a green laser at 532.

Watt-level diode-pumped thulium lasers around 2.3 µm.

We report on efficient diode-pumped mid-infrared lasers based on :, :, and : crystals. These lasers operate in the continuous-wave (CW) regime and deliver watt-level output power at the wavelengths of 2.2-2.

Widely tunable in-band-pumped Tm:CaF laser.

This Letter presents the efficient laser operation of a : crystal in-band pumped at 1610 nm by an Er-Yb-codoped fiber laser system. A laser slope efficiency of 55% (versus incident pump power) was achieved in a continuous-wave regime, with a maximum output power of 1.25 W at ∼1.

Co-sputtered Pr-doped Ga-Ge-Sb-Se active waveguides for mid-infrared operation.

This work reports on the properties of luminescent waveguides based on quaternary Ga-Ge-Sb-Se amorphous thin films doped with praseodymium. The waveguides were fabricated via magnetron co-sputtering, followed by inductively coupled plasma reactive ion etching. The initial thin film thickness and optical properties were assessed and the spectroscopic properties of the waveguides were measured.

Comparative study of Er-doped Ga-Ge-Sb-S thin films fabricated by sputtering and pulsed laser deposition.

Despite the renewed interest in rare earth-doped chalcogenide glasses lying mainly in mid-infrared applications, a few comprehensive studies so far have presented the photoluminescence of amorphous chalcogenide films from visible to mid-infrared. This work reports the fabrication of luminescent quaternary sulfide thin films using radio-frequency sputtering and pulsed laser deposition, and the characterization of their chemical composition, morphology, structure, refractive index and Er photoluminescence. The study of ErI level lifetimes enables developing suitable deposition parameters; the dependency of composition, structural and spectroscopic properties on deposition parameters provides a way to tailor the RE-doped thin film properties.

Close look on cubic Tm:KYF crystal for highly efficient lasing on the H → H transition.

We report on Czochralski growth, detailed ground- and excited-state absorption and emission spectroscopy and highly-efficient mid-infrared (∼2.3 µm) laser operation of a cubic potassium yttrium fluoride crystal, Tm:KYF. The peak stimulated-emission cross-section for the H → H transition is 0.

Continuous-wave Tm:YAlO laser at ∼2.3 μm.

The orthorhombic Tm:YAlO crystal is promising for laser operation at the H3→F3 (1.5 μm) and H3→H3 (2.3 μm) transitions.

Thulium laser at ∼2.3 μm based on upconversion pumping.

We report on novel upconversion (UC) pumping schemes for 2.3 μm thulium (Tm) lasers (the H3→H3 transition) based on a photon avalanche mechanism populating the intermediate metastable level (F3) acting as an effective ground state. The proposed pump wavelengths are ∼1 and ∼1.

Ytterbium calcium fluoride waveguide laser.

Calcium fluoride is a well-known material for optical components. It is also suited for doping with rare-earth ions, e.g.

Laser operation of highly-doped Tm:LiYF epitaxies: towards thin-disk lasers.

Quasi-continuous-wave laser operation of 20 at.% Tm:LiYF thin films (84-240 μm) grown by Liquid Phase Epitaxy (LPE) on undoped LiYF substrates is achieved. The 240 μm-thick Tm:LiYF active layer pumped at 793 nm with a simple double-pass scheme generated 152 mW (average power) at 1.

7 to 8 µm emission from Sm doped selenide fibers.

We report on the observation of the long wave-infrared (LWIR) emission centered at 7.3 µm of Sm doped chalcogenide fibers. The chemical composition of the selenide glass host matrix (GaGeSbSe) enables the drawing of 500 ppm and 1000 ppm Sm doped fibers.

Watt-level Tm:LiYF channel waveguide laser produced by diamond saw dicing.

Low-loss surface channel waveguides with a cross-section of 30 × 30 μm are produced by diamond saw dicing of 6.2 at.% Tm, 3.

Co-doped Dy and Pr GaGeSbS fibers for mid-infrared broad emission.

Rare earth ion doped materials are means to obtain cost-effective infrared light sources, with enough brilliance for applications such as gas sensing. Within a sulfide matrix, the simultaneous luminescence of both Pr and Dy in the GaGeSbS glass is reported. The use of these two rare earths is giving rise to a broad continuous luminescence in the 2.

8 μm luminescence from a Tb GaGeSbSe fiber.

In this Letter, we report for the first time, to the best of our knowledge, on an emission at 8 μm from Tb-doped GaGeSbSe chalcogenide fibers with doping levels at 1000 ppm and 500 ppm. These fibers were drawn following conventional melt-quenching methods and pumped at 2.05 μm using a Tm: YAG laser.

The nitrogen concentration effect on Ce doped SiON emission: towards optimized Ce for LED applications.

Ce-Doped SiON films are deposited by magnetron reactive sputtering from a CeO target under a nitrogen reactive gas atmosphere. Visible photoluminescence measurements regarding the nitrogen gas flow reveal a large emission band centered at 450 nm for a sample deposited under a 2 sccm flow. Special attention is paid to the origin of such an emission at high nitrogen concentration.

2.3 μm Tm:YLF mode-locked laser.

A passively mode-locked Tm:YLF laser emitting at 2.3 μm is reported for the first time, to the best of our knowledge. The continuous-wave stable mode-locking operation is obtained with a semiconductor saturable absorber mirror at a repetition rate of 100 MHz.

Guided Photoluminescence from Integrated Carbon-Nanotube-Based Optical Waveguides.

Thin films and ridge waveguides based on large-diameter semiconducting single-wall carbon nanotubes (s-SWCNTs) dispersed in a polyfluorene derivative are fabricated and optically characterized. Ridge waveguides are designed with appropriate dimensions for single-mode propagation at 1550 nm. Using multimode ridge waveguides, guided s-SWCNT photoluminescence is demonstrated for the first time in the near-infrared telecommunications window.

Broadband-tunable CW laser operation of Pr(3+):LiYF(4) around 900 nm.

We present here the first broadband-tunable CW laser operation of a Pr(3+)-doped LiYF(4) crystal in the 900-nm spectral range after pumping with an optically pumped semiconductor laser at 479 nm. It is confirmed that the entire emission band can be assigned to the same set of thermalized emitting levels (I(6)1,P3(0,1)). It is also demonstrated that laser performance could be improved up to laser slope efficiencies of about 33% with threshold absorbed pump powers not exceeding 100 mW.

Wavelength conversion in Er(3+) doped chalcogenide fibers for optical gas sensors.

We report for the first time the conversion of incoherent infrared light around 4.4µm into a near-infrared signal at 810nm in erbium-doped GaGeSbS fibers and bulk glass samples. This energy conversion is made possible by pumping erbium doped chalcogenide samples at 982 nm and simultaneously exciting them with a 4.

Emission properties and CW laser operation of Pr:YLF in the 910 nm spectral range.

The polarized emission spectra for the P→G emission transition of the Pr ion around 910 nm in the Pr:LiYF (Pr:YLF) laser crystal were registered and calibrated in unit of cross sections for the first time. Continuous-wave (CW) laser operation is demonstrated at 915 nm in π polarization by pumping the crystal with an optically pumped semiconductor laser (OPSL) at 479.2 nm.

Efficient laser-diode end-pumped Nd:GGG lasers at 1054 and 1067 nm.

Efficient and compact laser-diode end-pumped Nd:GGG simultaneous multiwavelength continuous-wave lasers at ∼1059, ∼1060 and ∼1062  nm were first demonstrated in a free-running 30 mm plano-concave laser cavity. The maximum output power was up to 3.92 W with a slope efficiency of about 53.