The UAB Research Foundation (The University of Alabama at Birmingham)

Other

The University of Alabama

Sergey B Mirov

Vladimir V Fedorov

Andrew Gallian

Alan Martinez

Igor Moskalev

Tasoltan T Basiev

Alex Dergachev

Alex Dergachey

Ramaz Sh Tedeev

Petr G Zverev

Ivan V Kuznetsov

William A Sibley

Vladimir V Federov

Galina Sergeevna Shevirdyaeva

Vyacheslav Vasil'evich Osiko

Yurii Vadirnirovich Orlovskii

Maxim Evgen'evich Doroshenko

Tasoltan Tazretovich Basiev

Valeri Vladimirovich Badikov

Dmitri Valer'evich Badikov

Dmitri Martyshkin

A Q-switched laser includes a laser cavity including a cavity mirror and an output coupler mirror. The Q-switched laser also includes a doped laser gain material disposed in the laser cavity and a Q-switch including a saturable absorber comprising Fe:ZnSe or Fe:ZnS.

Saturable absorbers for Q-switching of middle infrared laser cavities

A method of fabrication of laser gain material and utilization of such media includes the steps of introducing a transitional metal, preferably Crthin film of controllable thickness on the ZnS crystal facets after crystal growth by means of pulse laser deposition or plasma sputtering, thermal annealing of the crystals for effective thermal diffusion of the dopant into the crystal volume with a temperature and exposition time providing the highest concentration of the dopant in the volume without degrading laser performance due to scattering and concentration quenching, and formation of a microchip laser either by means of direct deposition of mirrors on flat and parallel polished facets of a thin Cr:ZnS wafer or by relying on the internal reflectance of such facets.

Mid-IR microchip laser: ZnS:Cr2+ laser with saturable absorber material

This disclosure demonstrates successfully using single, polycrystalline, hot pressed ceramic, and thin film Fe doped binary chalcogenides (such as ZnSe and ZnS) as saturable absorbing passive Q-switches. The method of producing polycrystalline ZnSe(S) yields fairly uniform distribution of dopant, large coefficients of absorption (5-50 cm) and low passive losses while being highly cost effective and easy to reproduce. Using these Fe:ZnSe crystals, stable Q-switched output was achieved with a low threshold and the best cavity configuration yielded 13 mJ/pulse single mode Q-switched output and 85 mJ in a multipulse regime.

Saturable absorbers for Q-switching of middle infrared laser cavaties

A method of fabrication of laser gain material and utilization of such media includes the steps of introducing a transitional metal, preferably Crthin film of controllable thickness on the ZnS crystal facets after crystal growth by means of pulse laser deposition or plasma sputtering, thermal annealing of the crystals for effective thermal diffusion of the dopant into the crystal volume with a temperature and exposition time providing the highest concentration of the dopant in the volume without degrading laser performance due to scattering and concentration quenching, and formation of a microchip laser either by means of direct deposition of mirrors on flat and parallel polished facets of a thin Cr:ZnS wafer or by relying on the internal reflectance of such facets. Multiple applications of the laser material are contemplated in the invention.

[object Object]

Electrically pumped mid-IR semiconductor lasers that are operable at room temperature and possess a range of tunability up to 1100 nm, which constitutes a revolutionary (1-2 orders of magnitude) improvement in the range of tunability over existing semiconductor laser technology utilizing Doped quantum confined host material (DQCH) with characteristic spatial dimension of the confinement tuned to enable the overlap of the discrete levels of the host and impurity ions and efficient energy transfer from the separated host carriers to the impurity, wherein: said DQCH material has the formula TM:MeZ and/or MeXZ, wherein Me is selected from the group consisting of Zn, Cd, Ca, Mg, Sr, Ba, Hg, Pb, Cu, Al, Ga, In; Z is selected from the group consisting of S, Se, Te, O, N, P, As, Sb and their mixtures; X being selected from the group consisting of Ga, In, and Al; and TM is selected from the group consisting from V, Cr, Mn, Fe, Co, and Ni.

Electrically pumped broadly tunable mid-infrared lasers based on quantum confined transition metal doped semiconductors

An optical nose for detecting the presence of molecular contaminants in gaseous samples utilizes a tunable seed laser output in conjunction with a pulsed reference laser output to generate a mid-range IR laser output in the 2 to 20 micrometer range for use as a discriminating light source in a photo-acoustic gas analyzer.

Mid-IR laser instrument for analyzing a gaseous sample and method for using the same

Mid-IR instrument for analyzing a gaseous sample and method for using the same

The invention relates to laser materials and specifically to single crystal active media for solid state lasers operating in the middle-infrared (Mid-IR) 4-5 &#x3bc;m range of optical spectrum, wherein a cross section of stimulated emission and laser wavelength is shifted to the range of atmospheric transparency with a single crystal orthorhombic structure with space group D-Fddd. The material contains Lead, Gallium, Sulfur and is doped with Dysprosium according to general formula: PbDyGaS, where 0.0001&#x3c;x&#x3c;0.05. Lasers operating in this matter and in this spectral range are advantageous for lidar applications, free space communication, environmental monitoring, and other purposes.

Single crystal laser material and system containing the same material

A method of fabrication of laser gain material and utilization of such media includes the steps of introducing a transitional metal, preferably Crthin film of controllable thickness on the ZnS crystal facets after crystal growth by means of pulse laser deposition or plasma sputtering, thermal annealing of the crystals for effective thermal diffusion of the dopant into the crystal volume with a temperature and exposition time providing the highest concentration of the dopant in the volume without degrading laser performance due to scattering and concentration quenching, and formation of a microchip laser either by means of direct deposition of mirrors on flat and parallel polished facets of a thin Cr:ZnS wafer or by relying on the internal reflectance of such facets. The gain material is susceptible to utilization of direct diode or fiber laser pumping of a microchip laser with a level of power density providing formation of positive lens and corresponding cavity stabilization as well as threshold population inversion in the laser material. Multiple applications of the laser material are contemplated in the invention.

A superbroadband or multiwavelength laser transmitter source for wavelength-division multiplexing, two-wavelength interferometry, differential lidar and optical storage applications. Contrary to conventional tunable laser sources that can switch between different lasing wavelengths in a given wavelength band, the superbroadband laser simultaneously emits at multiple wavelengths. The basic idea of this system is to maintain simultaneous lasing operation in an optical active gain medium at different wavelengths. The system uses a novel dispersive cavity. By designing this cavity structure appropriately, the system creates its own microcavities each lasing at a different wavelength within the fluorescence band of the gain medium. Mode competition in the proposed cavity is absent and spectral range of simultaneous multi-frequency generation is considerably enhanced practically to the spectral width of the active media luminescence spectrum. As a result, the radiation of each mode with its own wavelength is amplified in the active media independently from the simultaneous amplification of the rest of the wavelengths.

Semiconductor laser with a superbroadband or multiline spectral output

The present invention is directed to a tunable, solid state laser utilizing room temperature, stable, color centers of LiF:F.sub.2.sup.+ ** material. Also disclosed is a method of lasing. An object of the present invention is to develop and optimize LiF:F.sub.2.sup.+ ** thermostabilized active media, to propose a method of pumping, and to realize a room temperature, stable and efficient operation of the color center laser. These and other objects are achieved by introducing special dopants in the crystal at the stage of crystal growing; applying special regimes of ionizing treatment of the crystal, resulting in thermostabilization of the F.sub.2.sup.+ centers in LiF crystals; and utilizing alexandrite laser radiation for color center crystal pumping with a pump radiation frequency which is appropriate for the selective excitation of the F.sub.2.sup.+ color centers. The invention can be used in cases when monochromatic laser emission tunable in the visible-infrared spectral region is required for solving problems in various fields of science and technology such as laser spectroscopy, photochemistry, photobiology, medicine, and the like.

Room temperature stable color center laser, LiF:F.sub.2.sup.+ **

The present invention is directed to a tunable, solid state laser utilizing room temperature, stable, color centers of LiF:F.sub.2.sup.+ ** material. Also disclosed is a method of lasing. An object of the present invention is to develop and optimize LiF:F.sub.2.sup.+ thermostabilized active media, to propose a method of pumping, and to realize a room temperature, stable and efficient operation of the color center laser. These and other objects are achieved by introducing special dopants in the crystal at the stage of crystal growing; applying special regimes of ionizing treatment of the crystal, resulting in thermostabilization of the F.sub.2.sup.+ centers in LiF crystals; and utilizing alexandrite laser radiation for color center crystal pumping with a pump radiation frequency which is appropriate for the selective excitation of the F.sub.2.sup.+ color centers. The invention can be used in cases when monochromatic laser emission tunable in the visible-infrared spectral region is required for solving problems in various fields of science and technology such as laser spectroscopy, photochemistry, photobiology, medicine, and the like.

Room temperature stable color center laserLiF:F.sub.2 +** material and

Disclosed is the use of Sc.sup.2+ based active crystalline luminescent media for laser systems, tunable in the UV-visible spectral range. The crystalline media are Sc-doped alkali-earth-halide crystals such as: (1) alkali-earth-halide combinations, such as MeF.sub.2, MeCl.sub.2,crystals; (2) mixed alkali-earth metal fluorides and chlorides, such as MeFCl, M.sub.x Me.sub.1-x F.sub.2 and M.sub.x Me.sub.1-x Cl.sub.2 crystals; and (3) complex fluoride crystals; wherein M and Me are Ca, Sr, Ba or Mg. These crystals have Sc.sup.2+ ion impurities providing stable optical centers that yield advantageous luminescent properties. The base crystal structure utilized determines the luminescent emission spectrum for the Sc.sup.2+ optical centers. By manipulating the base crystal, the maxima of the absorption and emission bands may be altered from UV-blue to red in the optical spectrum. The Sc.sup.2+ active crystalline luminescent media are initially doped with trivalent Sc.sup.3+ ions during crystal growth. The crystals are then subjected to subsequent processing, such as ionizing irradiation, additive calcining coloration, or electrolytic coloration, to transform Sc.sup.3+ ion impurities into an Sc.sup.2+ electron configuration.

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Vestavia Hills, AL, United States of America

Sergey B Mirov