Acetylene flame laser

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Drawing sheet — no readable text.

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United States Patent Office 1

Patented May 5, 1970

3,510,797 the two gases are applied through the tubes 5 under suit

ACETYLENE FLAME LASER able pressure. Reference numeral 7 denotes an exhaust Willem Cornelis Nieuwpoort and Richard Bleekrode, line.

Emmasingel, Eindhoven, Netherlands, assignors, by The ignition of the gases can be effected by means of a meSne assignments, to U.S. Philips Corporation, New 5 high frequency electrical discharge in the supply line of York, N.Y., a corporation of Delaware one of the gases leading to one of the tubes 5. The high Filed Aug. 24, 1965, Ser. No.482,116 w frequency discharge may be ended after the ignition of the Claims priority, application Netherlands, Aug. 29, 1964, flame; thus, a constant Supply of active gases is not neces

U.S. Cl. 331-945 3 Claims O The embodiment of FIGS. 1 and 2 provides for supply ing the reactive gases separately to the reaction chamber.

However, the device will operate equaly as well if the

ABSTRACT OF THE DISCLOSURE gases are first mixed and then supplied together through Aflame laser wherein light emission is stimulated by a 15 oneAtube 5 to the reaction chamber. particularly suitable reaction for the device described resonator reaction between two gases entering a resonator has been found to be the combustion of acetylene with from one or more gaps arranged parallel to the axis of the oxygen; with these gases, strong bands occur in the near reSOmator.

ultra-violet region and in the visible region.

Illustrative dimensions of a preferred embodiment of

This invention pertains to a device for producing light 20 the device described above were found to be as follows: by stimulated emission of radiation. The invention relates The reaction chamber was cylindrical and had a diameter in particular to such a device wherein the radiation is and length of 40 cm., each gap 6 was 20 cm. long and produced by means of chemically reacting gases. 0.5 cm. wide; acetylene and oxygen were applied under Proposals have been made to use chemically reacting a pressure such that, taking into account the influence of gases for producing stimulated emission of radiation, an 25 the pumping device connected to the exhaust line 7, the inversion in the population between two vibration levels pressure in the flame space was approximately 10 mm. of of an electron condition producing stimulated emission of mercury column. In general, it has been found that, to infra-red radiation. In these proposals, the gases are first obtain an optically homogeneous reaction zone and also converted into the active (atomic) condition; this may be 30 to restrict as much as possible the disturbing influence of done, for example, by means of an electric discharge. gas molecules colliding with each other, it is desirable to It has also been proposed to obtain stimulated emission choose the pressure in the reaction chamber to be between of microwave energy by using a reacting mixture of 1 and 50 mm. of mercury column.

atomic nitrogen and methylene chloride wherein inversion With a total supply of 20 cm.8 of acetylene of 1 atm. occurs between higher rotation levels of one of the inter 35 per second and complete combustion thereof, strong mediate products present. bands occur in the light in the proximity of 3900, 4300, It is a general object of the invention to provide a 4700, 5100, and 5600 AU which bands originate from device by means of which stimulated emission of light CH-groups and of double-bonded carbon atoms. Bands can be obtained; a more specific object is to provide Such also occur in the proximity of 2800 and 3100 AU; these a device using chemically reacting gases. 40 originate from OH-groups.

Briefly, in accordance with the invention, stimulated While the invention has been described with respect to light emission is produced by means of a flame reaction a specific embodiment, various changes and modifications supported by at least two gases, the latter maintaining a thereof will readily occur to those skilled in the art with self-supporting reaction. The reaction Space is arranged out departing from the inventive concept. For example, inside an optical resonator, the gases entering the resonator it is also possible to add metal compounds in gas form in from one or more gaps arranged parallel to the axis of the addition to the hydrocarbons; in this case, the metal atoms resonator. The gases contain carbon and hydrogen and can be brought to the inversion which is required for the conditions are maintained such that the released energy stimulated emission by collisions with high energy mole results at least partially in an overpopulation of one or cules or fragmentation products thereof. Ifrequired, it is more electron levels in the gases present or formed, Such 50 also possible to atomize solutions of compounds of metals overpopulation being sufficient for stimulated light emis in a gas current. Suitable metals are the transition metals sion to occur. and the rare earths,

As used in this specification, the term “flame reactions” What we claim is:

includes all self-supporting reactions of gas mixtures 1. A device for producing stimulated light emission by occurring with the production of energy; it is not limited 55 means of flame reactions comprising: an optical resonator, only to the combustion of a gas with air or oxygen. a reaction chamber inside said optical resonator, means The invention will be better understood from the follow for introducing acetylene and oxygen into Said chamber ing more complete description thereof taken in conjunc comprising at least one tubular element having one end tion with the accompanying drawing, wherein: terminating in a gap arranged parallel to the axis of the FIGS. 1 and 2 are both partly diagrammatic and partly cross-sectional views of a device according to the in 60 optical resonator, the released energy of the flame reaction vention. caused by the mixture of said acetylene and oxygen re In the figures, reference numeral 1 denotes a cylindrical sulting at least partially in an overpopulation of one Or reaction chamber. Two quartz windows 2 are arrangedat more electron levels in the gases present or formed, said the ends of reaction chamber 1 on narrow tubular exten 65 overpopulation being sufficient for stimulated light emis sions 3 as shown. The windows are arranged to make an sion to Occur.

angle less than the Brewster angle with the axis of the SyS 2. A device as claimed in claim 1, wherein the pressure tem and are advantageously made of quartz in order that of the reacting gases is maintained at a pressure of from the flames should not adversely affect them. Mirrors 4 1 to 50 mm. of mercury column. are provided and constitute the optical resonator of the 70 3. A device for producing stimulated light emission by system. Two glass tubes 5 are provided as shown, each means of flame reactions, comprising: an optical resona having agap 6 at its end opening into reaction chamber 1; tor, a reaction chamber inside said optical resonator,

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means IUr introducing acetylene and oxygen and gaseous OTHER REFERENCES metal compounds into said chamber comprising at least Wieder: “High Power Gas Laser Studies,” Interphase one tubular element having one end terminating in a gap Corporation, West Technical Proposal 62R-1, May, 1962, arranged parallel to the axis of the optical resonator, the 12 pages.

released energy of the flame reaction caused by the mix- 5 Barger et al.: “Optical Detection of Microwave Transi ture of said acetylene and oxygen resulting at least par- tions in Electronically Excited CN Produced by a Chemi tially in an overpopulation of one or more electron levels cal Reaction,” Phys. Rev. Lett, vol. 9, pp. 345-47, Oct. in the gases present or formed, said overpopulation being 15, 1962. - sufficient for stimulated light emission to occur. Wieder et al.: “Exploratory Research on Population In 10 versions in Gaseous Explosions,” Applied Optics Supple

References Cited ment on Chemical Lasers, pp. 187-192, January 1965. UNITED STATES PATENTS RONALD L. WIBERT, Primary Examiner 3,309,620 3/1967. De Ment ----------- 331-945 15 E. BAUER, Assistant Examiner