DE2608830A1 - Gas laser with closely limiting side walls - uses discharge chamber as waveguide whose surfaces are formed by two concentric cylindrical shells - Google Patents

Abstract

The discharge chamber of the gas laser is formed by closely adjacent walls so that it acts as a waveguide for the laser radiation. The waveguide surfaces are equidistant and extend transverse to the radiation direction in a manner exceeding their spacing. The laser resonator is formed by mirrors. The resonator arrangement either uses flat mirrors directly connected to the discharge chamber, or concave mirrors at a given distance from the discharge chamber. The waveguide surface from shells of two concentric cylinders. Preferably the resonator consists of concave toroidal mirrors. The laser gas may flow through the waveguide in the direction of the cylinder axis. Alternately the gas may flow orthogonally to the axis, the waveguide surfaces having perforations for the gas passage.

Description

Optical transmitter

The first stage in the development of optical transmitters, specifically of C02 lasers, with high power requirements is complete.

Nowadays there are CO2 lasers for material processing and communication in almost every desired performance range. Their disadvantage is that they are bulky are and, as far as they work with electrical excitation, very expensive electrical Require utilities. The latter effort is mainly due to the required extraordinarily high voltages, e.g. during electron injection can go up to the order of a million volts, conditionally.

For several years there has been a lot of work on gas lasers with a greatly reduced Volume worked. This led to the avoidance of high diffraction losses for the development of so-called waveguide lasers, in which the radiation on the wall to be led.

The waveguide principle has been used in microwave technology for a long time known and was introduced in the sixties in the form of doped optical fibers found in solid-state laser technology.

The waveguide principle not only enables a considerable reduction in size of the active laser volume, but also a considerable decrease as a result the necessary electrical excitation voltages. Today is already with simple Waveguide structures approx. 1.5 watts continuous power with a laser volume of only 0.1 cm3 achieved.

The disadvantage of the previously known waveguide lasers lies in the fact that the necessary to achieve high peak or long-term performance Enlarging to cubic centimeter or cubic decimeter volumes has considerable difficulty oppose: The enlargement can be done e.g. by waveguide bundles. In order to however, problems arise in the design of the resonators, since every waveguide would need its own mirror, which is hardly due to the narrow distances alone is possible.

Another way of enlarging is to use theoretically known waveguide surfaces, which are in one to their extension small distance opposite. However, this design now has the disadvantage that With the required size of the plates, radiation transverse to the connection axis the resonator mirror can occur, which leads to losses.

In contrast, the invention consists in instead of flat surfaces to use two concentric cylinder jackets as waveguide surfaces.

With this measure, which is the subject of the main claim, the Path to high-power waveguide lasers opened.

The subclaims contain details of the transmitter according to the main claim and dealt with possible variations; of these in particular the external stimulus of the laser gas in connection with metallic waveguide surfaces.

With regard to the simple basic structure described above of the transmitter, no drawing is made.

Documents considered: Propagation of ifrared light in flexible hollow waveguides, Applied Optics Vol. 15, page 145 ff (1976)

Claims (7)

Patent claims Qptical transmitter, consisting of an electrical excited gas laser, the discharge space of which is so limited by closely spaced walls is that it is used as a waveguide with two for the laser radiation that builds up in it Equidistant waveguide surfaces acts, the extent of which is perpendicular to the beam direction is large compared to their distance and its resonator either through directly flat mirrors adjoining the discharge space or by concavely curved mirrors Mirror is formed at some distance from the discharge space, characterized in that that the waveguide surfaces are the lateral surfaces of two concentric cylinders. 2. Optical transmitter according to claim 1, characterized in that the resonator is formed from concave toroidal mirrors. 3. Optical transmitter according to claim 1 and 2, characterized in that that the laser gas flows through the waveguide in the direction of the cylinder axis. 4. Optical transmitter according to claim 1 and 2, characterized in that that the laser gas flows perpendicular to the cylinder axis, the waveguide surfaces ft; have a network of small holes for the gas to pass through. 5. Optical transmitter according to claims 1 to 4, characterized in that that the excitation of the laser gas by means of radial discharges between the waveguide surfaces he follows. 6. Optical transmitter according to claims 1 to 4, characterized in that that the excitation of the laser gas by means of discharges in the direction of the cylinder axis he follows. 7. Optical transmitter according to claims 1,2,4, characterized in that that the laser gas is excited externally, i.e. outside the waveguide space, wherein the opposite waveguide surfaces are metallic.