JPS5878481A - Metal vapor laser - Google Patents

Abstract

PURPOSE:To decrease the noises in laser output light without decreasing the power of the laser output light, by making a density gradient of returning from metallic ions to metallic atoms gentle in the region wherein the mixing ratio of the densities of the metallic ions and the metallic atoms between the opening end of a capillary and a cathode is different. CONSTITUTION:In the capillary 10, a metal reservoir 24, which supplies Cd vapor, is attached to a position which is within approximately 5cm from the opening end of the capillary 10 on the anode side. A heater 26 is provided in said metal reservoir 24 in order to heat a Cd metal 28 in the metal reservoir 24. A coil shaped cathode 30 is provided at a position within 5cm from the opening end of the capillaryl 10. The discharge length from the opening end of the capillary 10 to the cathode 30 is maintained within 5cm. When the discharge is generated between the anode 20 and the cathode 30 and the metal vapor is supplied from the metal reservoir 24, substantial He gas discharge is generated between the tip of the anode 20 and the opening of the metal reservoir 24, and substantial mixed discharge of the Cd vapor and He gas is generated between the opening of the metal reservoir 24 and the cathode 30.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal vapor laser, and particularly to a metal vapor laser for achieving low noise.

Conventionally, in metal vapor lasers in which optical oscillation output can be obtained by exciting the Rede medium, that is, metal molecules, by the discharge generated between the anode and the cathode, noise occurs in the laser output light, which poses a practical problem. has been pointed out. In particular, H, -Cd lasers are subject to various practical limitations due to their large noise, and it is desired to reduce the noise.

Conventional* He-Cd Radhe, - as a method for reducing noise, Radheken qVoL, 8. There is a method of keeping the H gas pressure low, as described in M2 (1980) P2O3-414.

This method has a problem in that the Al density of the laser output light decreases.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a metal vapor laser that can reduce the noise of the laser output light without causing a decrease in the power of the laser output light. .

According to this invention, the space of the discharge path from the open end of the capillary to the cathode, which defines the discharge path between the anode and the cathode filled with a discharge material and supplied with metal vapor, is defined by the space between the metal ions in the capillary and the metal vapor. A metal vapor laser is provided that maintains a substantially equal mixing ratio of atoms and a discharge gas, a buffer gas.

By maintaining this mixing ratio within the capillary, noise contained in the laser output light is reduced.

In addition, the noise contained in the laser output light is reduced by making the density gradient returning from metal ions to metal spores gentler in the region where the mixing ratio of metal ions and metal atoms between the capillary opening end and the cathode increases. Ru.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an external mirror 1 according to an embodiment of the present invention! I
This figure shows a He-Cd laser device, in which a Ho-Cd laser discharge tube 6 filled with He at a predetermined pressure is placed between a pair of reflecting mirrors 2.4 forming an optical cavity. The discharge vessel 8 of this laser discharge tube 6 is
As shown in the figure, a capillary 10 in which a mixed discharge of H, gas, and Cd vapor occurs, and a Pryuster window 1:l, 14 for airtightly mounting the capillary 10 on both ends of this capillary 10 are shown in section 16. II
It is composed of I.

On the other hand, the Prewster window installation is in part 1#,
A first branch pipe 22 to which an anode 20 is fixed is provided. A metal reservoir 24 is attached to the capillary 10 for supplying C4 fumes within about 5 scratches from the anode-side open end of the capillary 10. Heater 16 for heating
is provided.

In one embodiment of the invention, the other Brewster window fitting 18 is connected to the capillary 10 via an extension 32 for housing the cathode jO;
A cathode 30 disposed within this extension 32 is formed in a coil shape, and this cathode 30 is connected to the capillary 10.
The discharge distance from the open end of the capillary 10 to the cathode 30 is maintained within 5 em. Further, this expanded portion 32 is provided with a Cd vapor coagulation portion 34 whose inner diameter is larger than that of other portions.

According to the embodiment of the present invention described above, when a discharge occurs between the anode 20 and the cathode 30 via the H8 gas and metal vapor is supplied from the metal reservoir 24, the discharge occurs between the tip of the anode 20 and the opening of the metal reservoir 24. At , a substantial H6 gas discharge occurs.

Laser output light is generated from the Brewster window 12.14 between the opening of the metal reservoir 24 and the cathode 30, and is led out from one of the reflecting mirrors 4.2. The noise contained in the laser output light is significantly reduced by 1- as shown in FIG. 2B compared to the conventional laser of FIG. 2A.

In other words, the radar output light obtained from a conventional laser contained as much as 17 peak-to-peak noises, whereas the laser output light obtained from this laser contained as much as 17 peak-to-peak noises. It is possible to keep the noise to between 2 and 8. The reason why the noise is reduced by the embodiments of the present invention is presumed to be based on the following fact. The Cd vapor transferred within the capillary 10 by the cataphoresis effect flows into the expanded portion 32 having a large space from the open end of the capillary 10, and is deposited on the Cd vapor coagulation portion 34.

Since the expansion part 32 into which Cam air is continuously introduced has a large space itself, the Cd vapor concentration therein does not increase, and the Cd vapor that flows into this space is
Since the inner diameter of the Cd vapor is expanded to make it easier to solidify, and the surface temperature is kept lower than that of other surface areas, the Cd vapor is solidified in the solidified part 34, so that the Cd vapor is solidified from the open end of the cavity 9-10. Mochima within 5aI is approximately capillary 10
H within the capillary 10 is maintained at a metal vapor concentration within
The mixing ratio of 8 gases and metal vapors is maintained. Since the cathode 30 is provided within approximately 5 scratches from the open end of the capillary 10, the mixed discharge generated within the capillary 10 is directly generated in the discharge path from the open end of the capillary 10 to the cathode 30, resulting in , it is assumed that the noise in the laser output light is reduced.

In the above embodiment, the metal reservoir 24 is connected to the cabinet 9-
10 and the metal vapor directly connects to the capillary, -1
It is supplied from the middle of 0. Furthermore, the metal vapor supply position is kept within approximately 5 es from the open end of the capillary 10 on the anode side. By attaching the metal reservoir 24 to the capillary 10 in this way, the metal 112
Between the opening in the capillary 10 of No. 4 and the tip of the anode 20, it is possible to substantially reduce noise during laser light output even though a substantial H1! gas discharge occurs.

FIG. 3 shows a modified embodiment of FIG. 1, in which the capillary 1
0 is long, indicating a radar in which two anodes 20a, 20b and two metal reservoirs j4a, j4b are provided for one cathode 30. In this embodiment of FIG.

An extension 32 is attached to the capillary 10, with the cathode 30 also located within 5 meters from its opening. Therefore, even with this modification example 1, noise in the laser output light can be reduced in the same way.

1, the same parts as shown in FIG. 1 are given the same reference numerals and additional symbols m and b, and the explanation thereof will be omitted.

FIG. 4 shows another embodiment of the present invention, in which a cathode accommodating section 38 for accommodating the cathode 30 is connected to the expanded section 32 via a branch pipe S6. The open end inside the expanded portion 32 of the capillary 10 is as follows.

On the centerline 40 of the opening in the extension 32 of the branch pipe 36 or
The centerline 40 of the opening and the Brewster window mount extend into the space between sections 18.

In this embodiment, the discharge path from the open end of the capillary 10 to the cathode 10 is bent, and the discharge path from the open end of the capillary 10 to the opening of the branch pipe 36 is bent. The Worcestershire wind installation will follow a path that points toward section 18 and then bends back toward the opening of branch pipe J6. In addition, the metal vapor transferred within the cavity 10 due to the cataphoresis effect.

The solidified portion 34 and branch pipe 3 within the expanded portion 32 flow into the expanded portion 32 from the open end of the capillary 10 without stagnation.
The liquid flows toward the coagulation section 42 provided protruding from the surface of the coagulation section 6, and is coagulated on the surface thereof.

Therefore, the noise in the radar output light is reduced because the density gradient when the fat ions in the discharge path return to metal atoms due to the action of heat generated by self-heating due to the discharge is made gentler.

Furthermore, as shown in FIG. 5, the capillary outer peripheral portion 44 of the extended portion S2 is formed more quickly than other portions,
It is preferable that the area of the cross section W is smaller than that of the cross section Wl of other parts.

Since the outer circumferential portion 44 is fast, this outer circumferential portion 44
The temperature inside is higher than that in other parts, therefore, Cd ions are gently attached to the solidified part j4, and the density gradient of ions and Cd atoms can be made gentle. In addition, it is desirable that the distance 1111* between the end of the outer circumferential portion 44 and the open end of the capillary 10 and the center line 40 be kept at 5 m or more to obtain a favorable effect. This has been experimentally confirmed.

As described above, according to the laser of the present invention, noise in the radar source can be reduced because unevenness of metal vapor is prevented from occurring.

Incidentally, in the above-mentioned embodiment, the m H@-cd laser was explained as an example, but this invention.

It is clear that the present invention is applicable not only to H.-c and loser but also to other metal lasers such as If, -8, and Hc-Cu lasers. Furthermore, it is clear that the present invention can also be applied to lasers that use a combination of metal vapor radar and the like to control the buffer gas.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing an embodiment of the metal vapor laser of the present invention, and FIGS. 2A and 2B show the characteristics of laser output light from the present invention and the conventional metal vapor laser, respectively. The graph, FIG. 3, first time, and FIG. 5 are cross-sectional views showing other embodiments. 2.4...Reflector, 6...Laser discharge tube, 8...
・Discharge vessel, 10... Capillary, 12.14...
・Prewster Wind, 20...Anode. 21.36...Branch pipe, 24...Metal reservoir, SO...
Cathode, 32... Expansion part, 34.42... Coagulation part. 38...Cathode Storage Department Representative Patent Attorney Takehiko Suzue Showa Year Month Day 1. Incident display special axis Akira! 56-176848 No. 2, Name of the invention Metal vapor laser 3, Person making the amendment Relationship to the case Patent applicant Kinmen Electric Co., Ltd. 4, Agent 5, Spontaneous amendment 7, Details of the amendment, page 112, line 8 [ He -Cu L/-day'v
[l(e-Cu laser) 62 Correct.

Claims (1)

[Claims] fil An anode storage part, a cathode storage part, and an anode storage part and a cathode storage part are connected. a discharge vessel comprising a capillary defining a discharge path;
A metal vapor comprising the anode provided in the anode housing, the cathode provided in the cathode housing, gas filled in the discharge vessel, and means for supplying metal vapor into the discharge vessel. In laser,
III. A metal vapor radar characterized in that when a discharge occurs between an anode and a cathode, a region where metal ion and metal atom density is non-uniform in the discharge path from one end of the capillary to Vζ is reduced. (2) Said The metal vapor radar according to claim 1, wherein the cathode is provided within 5 am in terms of discharge path length from one end of the capillary. (14) The metal vapor laser according to claim 1 or 2, characterized in that the cathode storage section is connected to an expansion section attached to a capillary via a branch pipe. Metal vapor radar according to any one of claims 1 to 3 (5) A patent characterized in that the expanded portion includes a region where metal vapor mainly solidifies. Metal vapor laser (6) according to claim 4, wherein the capillary extends into the expansion part,
A metal vapor laser 171 according to claim 4 or 5, characterized in that the metal vapor laser 171 crosses over the connecting opening of the branch pipe. Between the tip of the capillary and the central axis of the connecting opening of the front wide branch pipe is , 5- or more. The metal vapor laser according to claim 6 or 7, characterized in that the metal vapor laser is small in size.