Nanosecond Pulsed Longitudinal Discharge Research Articles

High-Power Single-Tube Sr Vapor Laser Oscillating in the Mid-IR Spectral Range

A large-bore Sr vapor laser excited in a nanosecond pulsed longitudinal discharge is reported. The optimal discharge conditions for achieving a maximal average output power at several Sr atom and ion lines in the mid-IR spectral range are determined. High average output power of 29 W (at 25 kHz pulse repetition frequency) and laser pulse energy of 2.9 mJ (at 5 kHz pulse repetition frequency) are obtained at the multiline operation. These values are more than two times better than the ones achieved so far with a single-tube strontium or strontium halide vapor lasers.

High-power copper bromide vapor laser

A large-volume single-tube CuBr vapor laser, oscillating on the atomic copper self-terminating lines of λ510.6 nm and λ578.2 nm, is described. Characteristics of the nanosecond pulsed longitudinal discharge excitation for a maximum output power on these laser lines are found. A record-high average laser power of 140 W for atomic self-terminating CuBr vapor lasers is reported.

Theoretical determination of the gas temperature in a nanosecond pulsed longitudinal discharge exciting high-power strontium atom lasers

Assuming that the gas temperature varies only in the radial direction, an analytical solution of the steady-state heat conduction equation is found for a uniform power input in various gas mixtures and for different discharge tube designs. For this purpose, the heat conductivities of several 2- and 3-component gas mixtures are obtained under gas-discharge conditions optimal for the strontium atom laser.

Theoretical study on some plasma parameters and thermophysical properties of various gas mixtures in gas-discharge lasers

Using the well-known Wassiljewa equation and a new simple method, the thermal conductivities of various 2- and 3-component gas mixtures were calculated and compared under gas-discharge conditions optimal for two prospective lasers excited in a nanosecond pulsed longitudinal discharge. By solving the non-stationary heat-conduction equation for electrons, a 2D numerical model was also developed for determination of the radial and temporal dependences of the electron temperature Te(r, t).

Determination of spatially-resolved electron temperature in nanosecond pulsed longitudinal discharges

Using the results for the time- and spatially-averaged electron temperature, which were previously obtained by the line-ratio method of optical emission spectroscopy for several metal halide vapour lasers excited in nanosecond pulsed longitudinal discharge and analytically solving steady-state heat conduction equation for electrons as well, radial distribution of electron temperature, i.e. spatially-resolved electron temperature, is obtained.

A simple method for experimental determination of electron temperature and electron density in a nanosecond pulsed longitudinal discharge used for excitation of high-power atomic and ionic metal and metal halide vapour lasers

A simple method based on the time-resolved measurement of electrical discharge parameters, such as tube voltage and discharge current, is developed and applied for determination of electron temperature and electron density in the discharge period of a nanosecond pulsed longitudinal discharge, exciting high-power DUV Cu+ Ne-CuBr, He-Hg+ and He-Sr+ lasers.

2D numerical modelling of gas temperature in a nanosecond pulsed longitudinal He-SrBr2 discharge excited in a high temperature gas-discharge tube for the high-power strontium laser

An active volume scaling in bore and length of a Sr atom laser excited in a nanosecond pulse longitudinal He-SrBr2 discharge is carried out. Considering axial symmetry and uniform power input, a 2D model (r, z) is developed by numerical methods for determination of gas temperature in a new large-volume high-temperature discharge tube with additional incompact ZrO2 insulation in the discharge free zone, in order to find out the optimal thermal mode for achievement of maximal output laser parameters. A 2D model (r, z) of gas temperature is developed by numerical methods for axial symmetry and uniform power input. The model determines gas temperature of nanosecond pulsed longitudinal discharge in helium with small additives of strontium and bromine.

Determination of space-time resolved electron temperature in nanosecond pulsed longitudinal discharge in various noble gases and discharge tube constructions

Using our results obtained by the analytical solution of the steady-state heat conduction equation for electrons and deriving a new thermal conductivity, 2D (r, t) numerical solution of nonstationary heat conduction, an equation for electrons is found for nanosecond pulsed longitudinal discharge in helium for two different pressures and in neon.

2D numerical modelling of the gas temperature in a high-temperature high-power strontium atom laser excited by nanosecond pulsed longitudinal discharge in a He-SrBr2 mixture

Assuming axial symmetry and a uniform power input, a 2D model (r, z) is developed numerically for determination of the gas temperature in the case of a nanosecond pulsed longitudinal discharge in He-SrBr2 formed in a newly-designed large-volume high-temperature discharge tube with additional incompact ZrO2 insulation in the discharge-free zone, in order to find the optimal thermal mode for achievement of maximal output laser parameters. The model determines the gas temperature of a nanosecond pulsed longitudinal discharge in helium with small additives of strontium and bromine.

High-power metal halide vapour lasers oscillating in deep ultraviolet, visible and middle infrared spectral ranges

Middle infrared and deep ultraviolet high-power high-beam-quality stable-operating He-SrBr2 and Cu+ Ne-CuBr lasers excited in nanosecond pulsed longitudinal discharge are developed, patented and studied. Optimal discharge conditions, such as active zone diameter, vapour pressure, buffer-gas pressure, electrical excitation scheme parameters, average input power and pulse repetition frequency, are found. The highest output laser parameters are obtained for the Sr atom and Cu+ lasers, respectively. These lasers equipped with optical systems for the control of laser radiation parameters are used in a large variety of applications, such as precise material microprocessing, including biological tissues, determination of linear optical properties of different newly developed materials, laser-induced modification of conductive polymers and laser-induced fluorescence in wide-gap semiconductors, instead of free electron and excimer lasers, respectively. A master oscillator-power amplifier system, which is based on a high-beam-quality high-power CuBr vapour laser and is equipped with an optic system for laser beam control and with the X–Y stage controlled by adequate software as well, is developed and used in high-precision micromachining of samples made of nickel and tool steel.

2D numerical modeling of the gas temperature in a large-volume high-temperature nanosecond pulsed longitudinal discharge in helium with small admixtures of neon, strontium and bromine

A numerical 2D model (r, z) of the gas temperature was developed for the case of axial symmetry and uniform power input. The model determines the gas temperature of a nanosecond pulsed longitudinal discharge in helium with small additives of neon, strontium and bromine. The gas discharge is excited in the newly designed large-volume high-temperature discharge tube.

Analytical calculation of the gas temperature and time-resolved measurement of the electron temperature of a gas discharge in He and Ne-He mixtures

The gas and electron temperatures were determined in a nanosecond pulsed longitudinal discharge in a new high-temperature discharge tube design developed for a high-power large-volume middle-infrared He-SrBr2 laser. Assuming that the gas temperature varies only in the radial direction, analytical solution of the steady-state heat conduction equation was obtained at uniform power input and, for the first time, for each zone of the discharge tube, namely, discharge zone, ceramic tube, discharge-free zone incompactly filled with zirconia fibers insulation, and quartz tube. The line-ratio optical emission spectroscopy method was used to determine experimentally for the first time the time-resolved electron temperature in the discharge afterglow, namely, measurement of the relative intensities of some He and Ne spectral lines originating from different upper levels. The average values of the electron temperature were also found by averaging the time-resolved electron temperature over the time.

High-Power Sr Atom Laser Excited in Nanosecond Pulsed Longitudinal $\hbox{He-SrBr}_{2}$ Discharge

An active volume scaling in bore and length of an Sr atom laser excited in a nanosecond pulsed longitudinal He-SrBr2 discharge is carried out. The optimal discharge conditions for achieving of a maximal average output power at several Sr atom and ion lines are found. At multiline operation, a record average output power of 4.26 W is obtained, more than 90% of which is concentrated on the 6.45- mum Sr atom line.

Strontium atom laser excited by nanosecond pulsed longitudinal He-SrBr2 discharge

An investigation of a strontium bromide vapour laser excited by a nanosecond pulsed longitudinal discharge is presented. The optimal discharge conditions for laser oscillation on several Sr atom and ion lines are found. At multiline output an average laser power of 2.4 W is obtained, more than 80% of which is concentrated at the 6.45 µm Sr atom line.

UV lasing on Cu/sup +/ in a Ne-CuBr pulsed longitudinal discharge

UV lasing on copper ion transitions in CuBr vapor laser has been obtained in a nanosecond pulsed longitudinal discharge with Brewster windows and external mirrors. A record small-signal gain per unit length has been achieved (up to 19%/m and 16%/m for the 238.6- and 270.3-nm transitions, respectively). Infrared (IR) laser action on Cu ions in a He-CuBr discharge and on Ag ions in a He-AgI (silver iodide) discharge has also been observed. A maximum average output power of 430 mW has been achieved multiline (740.4-780.8 nm) on the Cu+ IR transitions. A maximal gain of 58%/m has been obtained on the strongest 780.8-nm transition.