The Uab Research Foundation

The University of Alabama

Vladimir V Fedorov

Sergey B Mirov

Andrew Gallian

Alan Martinez

Igor Moskalev

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

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.

Growing community of inventors

Birmingham, AL, United States of America

Vladimir V Fedorov