RU2243619C2 - Active element of metal halide vapor laser - Google Patents

Abstract

FIELD: metal halide vapor lasers.

SUBSTANCE: proposed active element has vacuum-tight shell provided with at least two electrodes on its ends, spent working material traps, and containers periodically arranged throughout entire length of working channel which are filled with working material such as copper bromide. In addition it has heat chamber enclosing working channel with containers and means for controlling temperature of containers and working channel. Containers are made in the form of annular cavities tightly enclosing working channel of vacuum-tight shell that has internal holes at points where it is enclosed by containers to pass working material vapors to working channel; spent working material traps are made in the form of part of vacuum-tight shell widening over its entire circumference. In addition bottom part of heat chamber is double-section part with inner and outer walls having holes in inner wall and fans in outer one.

EFFECT: enhanced service life of laser due to optimal temperature difference of containers and working channel.

5 cl, 1 dwg

Description

The invention relates to the field of quantum electronics and can be used to create lasers based on vapor of metal halides, for example copper bromide.

Known gas discharge tube laser with a pair of copper halide [US, No. 463 5271, A, 1987], including a vacuum-tight shell, equipped in its lower part with containers in the form of processes for placement of copper halide, such as copper bromide, which are surrounded by electric heaters or furnaces to create the necessary vapor pressure of the working substance. An improvement according to the invention of a known tube is an electrode consisting of copper particles that are poured into a perforated quartz tube soldered into the outer quartz cavity and connected with a vacuum power supply via vacuum-tight leads.

A further improvement of such an experimental device and the closest in technical essence to the proposed invention is the device described in [A 50 - Watt copper bromide laser. SPIE. 2001. V.4184. P.203-206]. In the lower part of the active zone of the gas discharge tube there are containers for placing copper bromide, while the active zone of the gas discharge tube with containers is surrounded by a heat chamber in which heaters are mounted, as well as means for controlling the temperature of containers with copper bromide.

The above construction, as well as its analogue, has the following disadvantages: when using a laser, two power sources are used - a gas discharge tube power source and a container heaters power source, which require stabilization of their operation and their mutual stabilization for optimal laser operation. A sufficiently close arrangement of the container heaters to the channel of the gas discharge tube leads to the appearance of bias currents, which, in turn, leads to uncontrolled redistribution of power between the power sources, and, as a result, to overheating of the containers and the intensive intake of copper bromide vapors into the active, near-electrode, and end zone, and in some cases at high supply voltages - to the breakdown of quartz.

The problem that the proposed design of the active element of the metal halide vapor laser, in particular copper bromide, solves is to increase the laser life by creating the optimal temperature difference between the containers and the working channel with this design by stabilizing the temperature of the containers.

The problem is solved in that, like the known design, the proposed active element of the metal halide vapor laser contains a vacuum-tight shell with exit windows at its ends, two at least electrodes at its ends, filled with copper chips, a working channel with traps of the spent working substance, a heat chamber, containers with a working substance, for example, copper bromide, located along the entire length of the working channel and means for controlling the temperature of the containers.

Unlike the known design, the containers are made in the form of annular cavities, hermetically covering the working channel of the vacuum-tight shell, inside of which holes are made in places where it is covered by containers for the vapor of the working substance to enter the working channel.

In addition, the diameter (D) of the outer surface of the annular cavity is 1.5-2.5 of the diameter (d) of the vacuum-tight shell, and the width (b) of the container is not less than the diameter (d) of the vacuum-tight shell.

In addition, the traps of the spent working substance are broadening around the entire circumference of the vacuum-dense shell and at least one located on both sides of the electrodes. The width of the traps is not less than the width of the containers.

Additionally, to maintain the operating temperature, sections of the working channel enclosed between the containers are wrapped with a heat insulator, for example, kaolin wool.

In addition, the lower part of the heat chamber is double and has an inner and outer wall, while the inner wall has openings, and fans are mounted in the outer one.

The implementation of a vacuum-tight shell with the proposed shape and the corresponding placement of the metal halide relative to the working channel creates the conditions for a self-heating mode of the laser, in which the temperature of the working channel determines the temperature of the containers. As the active element is heated, a temperature is created sufficient to melt the working substance and to supply its vapor to the working channel through openings in a vacuum-tight shell.

The choice of values for the diameter of the container is determined by the following: if the value is less than the declared value, overheating of the container is possible, which leads to uncontrolled intake of metal halide vapor into the working channel; Exceeding the upper limit of this value may lead to underheating of containers. The smallest width of the containers is determined by the placement in it of a sufficient amount of metal halide for long-term operation and the heat removal necessary to create its vapor. The number of containers is determined by the uniform distribution of the metal halide vapor along the length of the working channel. The maximum width of the containers can be increased up to their connection with each other, with the condition that the partitions between them are maintained to prevent the discharge from penetrating into them.

Additional warming of the working channel with a heat insulator allows it to achieve the required optimum temperature for operation.

Placing the working channel in the heat chamber eliminates the need to insulate the containers with a heat insulator to form vapor of the working substance and makes it possible to control their temperature. The heat chamber is air-cooled and can have either a rectangular or cylindrical shape. Its walls should be separated from the walls of the vacuum-tight shell at a distance that eliminates the occurrence of a discharge between them. With significant dimensions of the heat chamber, the necessary temperature of the working channel is achieved by selecting a heat insulator. The number of fans built into the outer wall of the heat chamber is determined by the length of the working channel of the active element.

The stationary mode of operation of the active element at the optimum vapor pressure is maintained by cooling the containers inside the heat chamber. When the temperature in the chamber is exceeded, the fans automatically turn on and subsequently also automatically turn off when the temperature drops to the optimum level.

Figure 1 shows the design of the active element of the laser on a vapor of a metal halide.

The active element consists of a vacuum-tight quartz shell 1 with windows 8 at the ends, electrodes 2, a working channel 3, a heat insulator 4, holes 5 in the working channel, containers 6 with a working substance 7, traps 9, a heat chamber 10 with holes 11 in the inner wall and fans 12 in the outer wall, thermocouples 13 and temperature control unit 14.

The active element of the laser on the vapor of a metal halide (copper bromide) works as follows. When you turn on the switching power supply 15 to the electrodes 2 of the vacuum-tight shell 1 voltage is applied. In the working channel 3, a discharge is formed. Over time, conditions are created in the heat chamber 10 under which the walls of the working channel 3 reach the temperature necessary for the stationary mode of operation, and the temperature of the containers 6 becomes such that copper bromide 7 begins to melt and enters into the discharge in the form of vapor through openings 5, where the vapor copper bromide dissociate into bromine and copper atoms, followed by the excitation of copper atoms and the occurrence of generation. When the temperature inside the heat chamber 10 rises, feedback is triggered through the thermocouple 13 and the electronic temperature control unit 14 turns on the fans 12 until the temperature reaches the previous level.

Thus, the proposed design of the active element of the metal halide vapor laser avoids the use of external heaters, and the presence of feedback maintains a constant temperature difference between the working channel of the vacuum-tight shell and containers, in contrast to the known gas-discharge tube using copper bromide vapor. This results in longer laser life.

Claims (5)

1. An active element of a metal halide vapor laser containing a vacuum-tight shell with exit windows at its ends, at least two electrodes at its ends, a working channel with traps of spent working substance, a heat chamber, containers with a working substance, for example bromide copper, located periodically along the entire length of the working channel, and means for controlling the temperature of the containers, characterized in that the containers are made in the form of annular cavities, hermetically covering the working channel of a vacuum-tight shell, in which The holes are made in places where it is covered by containers for passing the vapors of the working substance into the working channel. 2. The active laser element according to claim 1, characterized in that the diameter of the outer surface of the annular cavity of the containers is 1.5-2.5 times the diameter of the vacuum-tight shell, and the width of the container is not less than the diameter of the vacuum-tight shell. 3. The active element of the laser according to claims 1 and 2, characterized in that the traps of the spent working substance are broadening around the entire circumference of the vacuum-dense shell, equal to the width of the containers. 4. The active element of the laser according to claims 1 to 3, characterized in that the sections of the working channel enclosed between the containers are wrapped with a layer of heat insulator, for example kaolin wool. 5. The active element of the laser according to claims 1 to 4, characterized in that the lower part of the thermal chamber is double and has an inner and an outer wall, while the inner wall has openings, and fans are mounted in the outer one.