JPH04125465U - carbon dioxide laser - Google Patents

Abstract

(57) [Summary] [Objective] To provide a laser device capable of promoting recombination of active media dissociated by discharge and preventing a decrease in efficiency. [Structure] A catalyst is placed in a resonant cavity while being protected from shock waves generated by discharge between electrodes, and the dissociated medium easily contacts the catalyst to increase the recombination rate.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a laser device, and more particularly, to a laser device that resides within a laser enclosure. One used to insulate the catalyst powder from strong electric fields and excite the laser gain medium. Gain protection while protecting the catalytic medium from shock waves caused by the discharge between paired electrodes The present invention relates to a laser device equipped with a catalyst container in which the medium can come into sufficient contact with the catalyst.

0002

[Conventional technology]

The active medium of a CO ₂ laser is a gas mixture of carbon dioxide, nitrogen, helium, sometimes mixed with other gases such as carbon monoxide or xenon. When an electrical discharge occurs in the gas, it excites the active medium and some of its components dissociate. In particular, CO ₂ dissociates into CO and oxygen. This dissociation of gas reduces the volume of the active medium, which is a major cause of failure in sealed CO ₂ lasers.

Attempts have been made to reduce the deleterious effects of gas dissociation, for example by storing and using large amounts of gas or by exploiting the catalytic effects of the dissociated components. The most used technology in _CC2 lasers uses catalysts to promote the recombination of dissociated components. Carbon monoxide and nitrogen do not recombine at room temperature, but under certain conditions and in the presence of certain catalysts. Although platinum is a well-known catalyst, it requires operating the laser at elevated temperatures that are not suitable for sealed _CO2 lasers. A commercially available mixture of manganese oxide (MnO ₂ ) and cuprous oxide, such as Hopcalite, may be used as a catalyst. The biggest problem is that the catalyst powder is dispersed throughout the laser envelope, reducing the efficiency of the laser, especially if some of the catalyst powder is deposited on the optics.

[0004] RB Gibson et al.'s “Sealed Multiatmosphere CO ₂ TEA Laser: Seed-Gas compatible system using unheated oxide catalyst” published in Appl. Phys. A laser device is shown that must be confined outside the laser envelope and circulate the gas through the catalyst powder.

[0005]

[Summary of the idea]

The present invention places the catalyst inside a sealed resonant cavity, and the strong A pair of It protects the catalyst from the shock wave caused by the discharge between the electrodes and at the same time protects the gain medium from contact. To provide a catalyst container that can sufficiently contact a medium. The container is a conductive solid housing and a conductive cover that is permeable to the gain medium and impermeable to the internal catalyst. It is formed from. The container is placed in the resonant cavity in close proximity to the discharge region and is The dissociated component formed by this process is brought into sufficient contact with the catalyst. more desirable , the container is in contact with one of the electrodes. With this configuration, the discharge Therefore, the heat generated at the electrode is transferred to the catalyst through the container, increasing the recombination rate. let

[0006]

【Example】

The present invention will be explained in detail below according to examples.

Referring to FIGS. 1A-1C, a sequestered CO ₂ lateral electric field atmospheric pressure (TEA) laser 10 is shown. The enclosure 12 is used to house the gain medium 13 and the two main electrodes 14 and 16. Electrode 14 is attached to one wall of enclosure 12 and separated therefrom by screw 20 and spacer 18 . Electrode 16 is attached to the opposite wall of enclosure 12 by screws 20 and separated from that wall by spacer 22 and catalyst container 40. The relative sizes of spacer 18, spacer 22, and catalyst vessel 40 define the spacing between electrodes 14 and 16, and are selected to a predetermined spacing to suit the requirements of a particular application. Catalyst vessel 40 is formed from a trough housing 26 and an end cover 28. The housing 26 is made from a solid conductive material, such as aluminum, and the cover 28 is made from a conductive material, such as a stainless steel screen with a predetermined size mesh, having a predetermined size opening. The function of the cover 28 will be explained below, but here it is important to note that the cover 28 allows the gain medium 13 or its components to pass freely therethrough, while preventing even the smallest particles of the catalyst from passing out of the container. I will only state the following. Catalyst vessel 40 is assembled inside laser enclosure 12 by securing the base of housing 26 to the back side of one electrode, and also to the edges of housing 26, cover 28, and spacer 22. This is accomplished, for example, by screwing screws 20 into corresponding holes in laser enclosure 12, housing 26, cover 28 and electrode 16. Spacer 24 is used to add rigidity between cover 28 and the inner surface of housing 26 and to seal the contents of container 40 from the threaded hole. A spacer 22 is used between the cover 28 and the wall of the enclosure 12 to maintain sufficient volume or space to allow the gain medium 13 to circulate past the cover 28. A mixture of manganese oxide and Daiichi steel oxide, such as hopcalite, is used as a catalyst. This catalyst may be in the form of an unsolidified powder or solidified into pellets of an appropriate size. The catalyst vessel 40 and electrode 16 allow the gain medium to circulate and contact the cover 28 of the vessel 40. The cover 28 of the container 40 has a mesh size that allows the catalyst powder to pass through and the gain medium to pass through. Thus, although the gain medium 13 can enter the cover 28 and come into contact with the catalyst powder 30, even the smallest particles of the catalyst powder 30 cannot pass through the cover 28 and into the gain medium 13, and are not allowed to pass through the cover 28 and into the delicate optics of the laser. No particles are deposited on the surface. Typically a mesh size of 40 micrometers is used.

[0008] A discharge control device 60 is provided to generate a discharge between electrodes 14 and 16. The gain medium 13 is excited and a laser pulse is generated. used in resonator mode. When used, a total reflection mirror 50 reflects the light of the laser 10 at one end of the enclosure 12. A partially transparent mirror 52 is positioned on the optical axis on the opposite side of the enclosure 12. placed on top. In another application, mirrors 50 and 52 are replaced with optical output windows. with its face oriented at Brewster's angle to the optical axis and the output laser pulse The polarity of is controlled in a known manner.

[0009] During laser operation, the presence of a strong electric field causes the catalyst pellets 30 to fragment and become tactile. A dispersion effect occurs in the medium powder. This de-energizes the laser action, especially for powder is deposited on the optical elements within the laser envelope 12, the degradation is significant. electrode 14 and The electrical discharge that occurs during this period produces a shock wave that has the harmful effects on the catalyst as described above. Occur. Housing 26 and cover 28 are sometimes referred to as Faraday cages. The dispersion effect of the strong electric field present within the laser envelope forms a conductive cage that dissipates It was found that the catalyst 30 was protected from. Container 40 also includes main electrodes 14 and 16. It protects the catalyst 30 from shock waves generated by the discharge between Prevent the volume from decreasing.

0010 The gas turbulence caused by the discharge between the main electrodes 14 and 16 is sufficient to provide adequate contact between gain medium 13 and catalyst 30 when positioned as It is understandable that That is, since the catalyst 30 is placed within the resonant cavity, recombination is prevented. The combined speed can be increased. between one of the side walls of the enclosure 12 and the electrode 16 The position of the extending container 40 also has the advantage that it is easy to install the container 40. Has a point. By using screws 20 and spacers 22 and 24, the container 40 can be firmly and reliably attached.

[0011] The discharge control device 60 provides energy to the discharge between the electrodes 14 and 16, Selectively control its repetition rate. The repetition rate of the electrical discharge depends on the temperature inside the laser enclosure. It is one of the variables that determines the degree of The MnO component of the catalyst powder is suitable for the low repetition rate of the laser. The CuO component is more effective in the lower temperature ranges encountered during high-repetition rate operation. It is more effective in the high temperature range that occurs during cropping. It combines with wider temperature Enable catalysis of dissociated gases over a range and select pulse repetition frequency. Gives you some freedom. The repetition frequency also affects the rate of gas dissociation due to the discharge to the catalyst. limited by the fact that the recombination rate cannot be exceeded.

0012 As shown in FIGS. 1A and 1B, catalyst container 40 is in contact with electrode 16. As shown in FIGS. child heat from the electrode 16 is transferred to the vessel 40 and then to the catalyst 30. Conveyed. This causes the temperature of the catalyst 30 to rise and the catalyst to affect the rate of recombination. Ru. The electrical discharge between electrodes 14 and 16 generates heat in the electrodes. If a DC discharge is used If so, the cathode will generate more heat than the anode. and maximum recombination To achieve this speed, the catalyst vessel 40 is connected to the cathode, such as the electrode 16 shown in FIG. 1A. must be in contact. In the case of no direct current discharge, the position of the container 40 is If there is effective thermal coupling on one side, that is, it is not a big problem due to heat conduction. .

[0013] Various changes may be made to the embodiments of the present invention within the scope of the present invention. is clear to those skilled in the art. For example, the actual location and specific shape of container 40 may be Can be modified to suit the enclosure. The container 40 is approximately uniform in the discharge area. It suffices if it is thermally coupled to one electrode. Therefore, the present invention is limited to the embodiments described above. It is not something that will be done.

[Brief explanation of drawings]

FIG. 1A is a cross-sectional view of a laser device according to an embodiment of the present invention. FIG. 1B is a cross-sectional view taken along line 1B-1B in FIG. 1A. FIG. 1C is a top view of the catalyst container used in the embodiment shown in FIG. 1A.

[Explanation of symbols]

12: Surrounding body 13: Gain medium 14, 16: Electrode 18, 22: Spacer 30: Catalyst 40: Container 60: Discharge control device

[Procedural amendment]

[Submission date] June 19, 1992

[Procedural amendment 1]

[Name of document to be amended] Specification

[Correction target item name] Figure 1

[Correction method] Change

[Correction details]

FIG. 1A is a sectional view of a laser device according to an embodiment of the present invention. 1B is a cross-sectional view of 1A taken along line 1B-1B. 1C is a top view of the catalyst container used in the example shown in 1A.

[Procedural amendment 2]

[Name of document to be corrected] Drawing

[Correction target item name] Figure 1

[Correction method] Change

[Correction details]

[Figure 1]

Claims (1)

[Scope of utility model registration request] 1. An active fluid gain medium, a sealed resonant cavity surrounding the active fluid gain medium, a catalyst disposed within the sealed resonant cavity, and an electric field generated within the resonant cavity. Means for protecting the catalyst from shock waves, the means comprising a conductive container in which the catalyst is placed, and having a part on a surface of the container that allows the gain medium to pass through but does not allow the catalyst to pass through. laser equipment.