摘要:
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−1) and low passive losses while being highly cost effective and easy to reproduce. Using these Fe2+: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.
摘要:
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 Fe2+:ZnSe or Fe2+:ZnS.
摘要:
A method of fabrication of laser gain material and utilization of such media includes the steps of introducing a transitional metal, preferably Cr2+ thin 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.
摘要:
A method of fabrication of laser gain material and utilization of such media includes the steps of introducing a transitional metal, preferably Cr2+ thin 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.
摘要:
Volumetric Bragg grating devices that operate in middle-infrared region of the spectrum and methods for producing such devices are described. Such a Volumetric Bragg grating device can be produced by forming a plurality of color centers within an alkali-halide crystal and selectively removing a subset of the plurality of color centers to produce variations in refractive index of the alkali-halide crystal in the middle-infrared spectral region and to thereby produce a volumetric Bragg grating that operates in middle-infrared spectral range.
摘要:
Methods, structures, devices and systems are disclosed for implementing a photothermal therapy using nanostructures. In one aspect, a device to produce a photothermal effect includes a particle having a molecular layer functionalized onto the external surface of the particle and structured to attach to one or more targeting molecules capable of binding to a receptor site of a cell, in which the particle is configured to absorb light energy at a particular wavelength to produce a plasmon resonance effect that causes the particle to emit heat energy. In some implementations, the device is deployed in an organism having a tumor that includes a plurality of the cell and binds to the receptor site of the tumor by the targeting molecules, in which the light energy is emitted at a region of the organism that contains the tumor and the heat energy causes cellular death of the tumor cell.
摘要:
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 Fe2+:ZnSe or Fe2+:ZnS.
摘要:
A method of performing spatial separation of different wavelengths in a single laser cavity includes generating, from a pump radiation source, pump radiations in spatially separate channels and focusing the generated pump radiations in the spatially separate channels towards an active gain medium having amplification spectra. The method also includes emitting from the active gain medium, amplified radiations of the spatially separate channels, each channel of the spatially separate channels representing a corresponding wavelength and focusing the emitted amplified radiations of the spatially separated channels towards an aperture. The method further includes suppressing, at the aperture, an off-axis mode of the amplified radiations of the spatially separate channels, diffracting the amplified radiations of the spatially separate channels received through the aperture to provide diffracted radiations and returning a portion of the diffracted radiations back to the aperture, and collimating the diffracted radiations of the spatially separate channel.
摘要:
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−1) and low passive losses while being highly cost effective and easy to reproduce. Using these Fe2+: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.
摘要:
Volumetric Bragg grating devices that operate in middle-infrared region of the spectrum and methods for producing such devices are described. Such a Volumetric Bragg grating device can be produced by forming a plurality of color centers within an alkali-halide or an alkali-earth fluoride crystal and selectively removing a subset of the plurality of color centers to produce variations in refractive index of the alkali-halide or alkali-earth fluoride crystal in the middle-infrared spectral region and to thereby produce a volumetric Bragg grating that operates in middle-infrared spectral range.