BG66683B1 - Laser tube for strontium infrared laser with strontium halide vapours - Google Patents

Abstract

The laser tube for strontium infrared laser with strontium halide vapours finds application in powerful laser systems used for laser ablation and modification of soft tissues and bones in surgery, dentistry, biophysics, and other scientific and applied science tasks. The laser tube for strontium infrared laser with strontium halide vapours consists of a quartz tube (1) with a coaxially arranged therein ceramic tube (2). Between the ceramic and quartz tubes there is arranged a thermo-insulation (3), two electrodes (4) and ends closed with small windows of calcium difluoride (5). Along the ceramic tube is placed the working substance strontium halide (6). The laser tube is coated with variable high temperature insulation (7) and enclosed by an external heater (8). To the electrodes is connected an excitation generator (9). The laser tube is inserted into the resonator (10). In this laser tube construction a results is controlling of the concentration of strontium atoms regardless of the input into the gas discharge an electrical power, which results in an increase of more than twice the output laser power.

Description

Field of technology

The invention relates to a laser tube for an infrared strontium laser with strontium halide vapor, in particular with a controlled temperature generating in the infrared region of the spectrum from 1 to 6.45 pm in a positive column of a pulsed longitudinal discharge in a mixture of helium buffer gas and vapor of strontium halide. Infrared strontium laser is used in powerful laser systems used for laser ablation and modification of soft tissues and bones in surgery, dentistry, biophysics and other scientific and applied tasks.

BACKGROUND OF THE INVENTION

Gas discharge tubes are known for gas lasers of strontium atoms generating in the infrared region of the spectrum from 1 to 6.45 pm [1], in which free strontium atoms are obtained by evaporation of strontium dibromide [2, 3]. The strontium bromide vapor gas laser consists of a gas discharge tube placed in a resonator and connected to an excitation system. The gas discharge tube consists of a vacuum-tight quartz housing in which a coaxial ceramic tube, at least two electrodes are located, and its two ends are closed with windows made of calcium fluoride. The working substance strontium bromide is placed along the length of the tube. In this design of the gas discharge tube, the concentration of evaporated strontium bromide depends on the electric power introduced into the gas discharge and as a consequence when introducing electric power over about 2 kW, the so-called "overheating" occurs, where the concentration of strontium atoms exceeds the optimum value. laser power decreases.

Technical essence of the invention

The gas discharge tube for the strontium halide infrared strontium laser generating in the infrared region of the spectrum from 1 to 6.45 pm consists of a vacuum-tight quartz casing with a coaxially placed ceramic tube, with between the ceramic tube and the quartz and the vacuum two electrodes and its ends are closed with windows of calcium fluoride. The working substance strontium halide is equidistantly placed along the ceramic tube. The gas discharge tube is placed in a resonator with laser mirrors for the infrared area.

The discharge tube is filled with helium buffer gas. The pipe is externally wrapped with insulating wool and is covered by an external heater. An excitation generator is included in the electrodes, which provides the excitation pulses with duration over 100 nsec and amplitude over 100 A and 10 kV. The infrared laser generates tens of kilohertz in the infrared region of the spectrum upon pulsed excitation in the positive pole of the discharge with a repetition frequency of the excitation pulses and a duration of tens of nanoseconds.

In the laser tube for the infrared laser with strontium halide vapor, during the operation of the laser, by changing the external thermal insulation and the temperature of the external thermal heater, due to the presence of thermal insulation between the inner ceramic tube and the quartz casing, conditions are created for electric power input. over 2 kW without obtaining a concentration of strontium atoms above the optimum and thus a higher output power of the laser is obtained.

Explanation of the attached figure

The figure shows a schematic diagram of the laser tube for infrared laser with strontium bromide vapor.

An exemplary embodiment of the invention

According to one embodiment shown in the attached figure, the laser tube for the infrared strontium laser with strontium bromide vapor consists of a laser quartz tube 1 with a coaxially located ceramic tube 2, between the ceramic and the quartz tube is located28

Descriptions of issued patents for inventions № 07.1 / 16.07.2018 laid thermal insulation of zirconium dioxide 3, two electrodes 4 and ends closed with windows of calcium fluoride 5. Along the length of the ceramic tube is placed the working substance strontium bromide envelope 6. The laser tube externally with insulating wool 7 and covered by an external heater 8. An excitation generator 9 is connected to the electrodes 4. The laser tube is placed in a resonator 10.

The action of the laser tube for the infrared strontium laser with strontium bromide vapor is as follows. The discharge tube is filled with helium buffer gas. Excitation pulses are supplied from the generator 9 to the electrodes 4 of the gas discharge tube with a duration of more than 100 nsec and an amplitude of more than 100 A and 10 kV. Under the action of the discharge, the walls of the ceramic tube 2 are heated to the temperature required for the operation of the laser, for example from 1200 to 1300 ° C. The working substance - strontium dibromide 6, evaporates and enters the core of the discharge. By electron shock, the molecules of strontium bromide dissociate into strontium and bromine atoms. Under the action of excitation pulses, strontium atoms are excited at the upper atomic or ionic laser levels. An inverse population is created and laser generation of the strontium atomic and ionic lines in the infrared region of the spectrum from 1 to 6.45 pm is obtained by pulsed excitation in the positive column of the discharge.

As the electric power introduced into the discharge increases, the concentration of strontium atoms increases, and when concentrated above the optimal value, the output power of the laser decreases sharply. Due to the new construction of the laser tube, due to the presence of zirconia thermal insulation between the ceramic tube and the quartz tube, the concentration of strontium atoms is controlled regardless of the electric power introduced into the gas discharge, which leads to more than twofold increase in laser output. .

Application of the invention

The invention finds application in powerful laser systems used for laser ablation and modification of soft tissues and bones in surgery, dentistry, biophysics and other scientific and scientific-applied tasks.

Claims (2)

Patent claims A laser tube for an infrared strontium halide vapor laser consisting of a quartz tube with a ceramic tube coaxially arranged therein, two electrodes and ends closed with calcium dihydrofluoride windows, characterized in that between the ceramic tube ) and the quartz tube (1) is placed high-temperature insulation (3), and the outer wall of the quartz tube (1) with covered by variable high-temperature insulation (7), and they are also covered by the external heating system (8). Laser tube for infrared strontium laser with strontium halide vapor according to claim 1, characterized in that the high-temperature insulation (3) is made of zirconium dioxide and the variable high-temperature insulation (7) is made of insulating wool.