Coherent, Inc.

Rofin-sinar, Inc.

Spectra-physics Gmbh

Dale E Koop

Joseph F Rando

Michael Arnett

Robert E Basanese

David A Dewey

David Trost

Hartmuth Hecht

Robert E Wallace

A handpiece for use in delivering the output beam of a laser to the surface of a patient's skin for performing a dermatological procedure. In a first and second embodiment of the present invention, the handpiece provides a highly collimated beam of a fixed, non-variable spot size which is largely insensitive to movement of the handpiece over a range of working positions. In a third embodiment the handpiece provides a highly collimated and well defined focused laser spot of variable size where for a selected spot size, the size is largely insensitive to movement of the handpiece over a range of working positions. In all of the embodiments, the highly collimated laser beam permits the surgeon performing the procedure to move the handpiece over a range of positions without significantly defocusing or altering the spot size of the beam.

Handpiece for producing highly collimated laser beam for dermatological

A slit incision handpiece that receives a circular laser beam, reshapes the beam to have an elliptical cross-section, and focuses the beam onto target tissue. Slit incisions of approximately the dimensions of the elliptical beam are formed by stationary exposures on the target tissue from the output of the slit incision handpiece.

Surgical laser handpiece for slit incisions

A hair transplant procedure is described which includes preparing a plurality of hair plugs from a donor site on the scalp. A corresponding number of incisions are drilled into the hairless recipient site using a pulsed laser beam. Preferably, the beam is generated from a high power, RF excited, carbon dioxide, slab waveguide laser. The pulse characteristics of the laser are chosen to ablate the tissue to the desired depth while minimizing bleeding. The plugs are inserted into the incision and hair growth in the recipient region is promoted.

Laser assisted hair transplant method

A resonator design is disclosed particularly suited for a RF excited, carbon dioxide, slab waveguide laser. The laser includes a pair of elongated electrodes spaced apart in a manner to define a slab discharge region having a narrow waveguide axis between the electrodes and a wide axis extending parallel to the electrode surfaces. The resonator is a hybrid design and is a stable, waveguide in the narrow axis, and a negative branch unstable resonator in the wide axis. A pair of mirrors are provided at each end of the electrodes to create a folded beam path in the wide axis. The folded configuration increases the effective length of the resonator which substantially increases the power stability of the laser. The multiple mirror resonator can also be used to increase the width of the discharge region while minimizing spherical aberrations. Each leg of the path has the alignment characteristics of a negative branch unstable resonator so that the alignment of the overall resonator is highly stable.

Gas slab laser with folded resonator structure

An laser system is disclosed for materials processing. The system includes an RF excited, conduction cooled, sealed gas laser. The lasing species in the gas mixture is an isotope of carbon dioxide and in the preferred embodiment is defined by the .sup.13 CO.sub.2 isotope. The use of the .sup.13 CO.sub.2 isotope functions to shorten the rise and fall times of the laser pulses. By this arrangement, the laser may be operated at higher repetition rates with a full depth of power modulation.

Materials processing with a high repetition rate isotopic carbon dioxide

A fast axial flow laser includes a vessel which houses heat exchangers and a pump which imparts the pumping action throughout the laser. Only one housing is necessary and this housing can also be used as an optical bench for the resonator. In one embodiment a positive displacement rotary pump is utilized and a retoreflector included to mount three fold mirrors. In the folded configuration the retroreflector provides angular stability in any two orthogonal planes parallel to the laser beam.

Fast axial flow laser circulating system

A high powered beam dump apparatus and method for absorbing the power of a high power laser, while the beam is shuttered off from contact with a workpiece, comprises two principal features. A reflecting cone reflects and spreads the high power laser beam outwardly from the axis of a high power laser beam when the beam dump is positioned with the axis of the cone coaxial with the axis of the incoming laser beam. An absorber extends circumferentially about the reflecting cone surface and absorbs the power of the beam as reflected from the reflecting cone surface. The materials and surface finishes of the conical reflecting surface and the absorber and the angle of the reflecting cone are related to the wavelength of the high power laser beam with which the beam dump is associated so as to absorb essentially all of the power of the laser beam when the beam dump is moved into the beam shuttered off position.

High powered beam dump

An alignment apparatus for aligning a main, high power laser beam with a workpiece by the use of a low power laser beam while the main, high power laser beam is shuttered off from contact with the workpiece includes a periscope for displacing the low power beam laterally to be coaxial with the axis of the first beam during the time that the high power beam is shuttered off from the workpiece. The alignment apparatus includes adjustment mechanism for adjusting the angular position of the low power laser to make the axis of the low power laser beam exactly parallel to the axis of the high power laser beam for the particular periscope being used.

Alignment laser periscope

A co-axial laser tube structure of the kind used in a flowing gas laser has an inner axially extending tube for confining the flowing gas in a discharge region, a single pin cathode mounted adjacent the hot end of the inner tube, a single pin anode mounted intermediate the cool end and the hot end of the inner tube, a gas entrance orifice for permitting gas to flow from the exterior tube into the interior of the tube at the location of the anode electrode means, and an outer tube which is separate from and which extends co-axially with the inner tube. The outer tube is made of plastic and conducts flowing gas along the outside of the inner tube from the cool end to the gas entrance orifice. The co-axial laser tube structure includes tube installation and mounting means effective to permit installation and/or replacement of the inner and outer tubes without the need for subsequent adjustment or bore registration of the tubes. The inner surface of the inner tube is frosted to minimize parasitic modes which could be produced by diffracted light impinging on the inside surface of the inner tube at a grazing angle and also for decreasing the boundary layer of thickness to improve turbulence in the gas flow between the anode and the cathode. The installation and mounting means include shaft seals, chamfers and related O-rings which are effective to hold the co-axial laser tube structure in registration with the bore without over contraint. The centering ring at the hot end of the inner tube has an aperature which shadows the glass tube from any diffracted light of the laser beam. This centering ring has an inner gas flow opening which is curved with a sufficiently large radius to eliminate any turbulence in the gas flow through the opening. A downstream diffuser recovers some velocity head of the gas flowing through the centering ring.

Flowing gas laser discharge tube structure

A flowing gas laser, of the kind in which gas flows continuously through the lasing region and is circulated through the heat exchanger for cooling before being returned to the lasing region, comprises a resonator module and a blower module. The optical components of the laser are mounted on an outer surface of the resonator module, and the resonator module has an interior structure for conducting the circulating gas to the lasing region. The blower module has heat exchange structure for cooling the circulating gas and has a blower for pumping the circulating gas. The blower module is physically separated from the resonator module to prevent the heat and vibration of the blower module from distorting or otherwise affecting the structure or the performance of the optical components. Ducting the interconnects the resonator module and the blower module for circulating the gas between these modules. Precision bore and pin structures are used for mounting all of the support structure for the laser at predetermined, fixed positions on the resonator module without the need for subsequent adjustment of such support structure.

Resonator module and blower module assembly

A floating mirror mount for a mirror of a laser comprises a mirror having a front surface and a back surface. A keeper encircles the mirror and has a peripheral flange which engages the front surface of the mirror when the mirror mount is not installed in a laser. A retainer is connected to the keeper and has a spring seating surface. A movable spring plate has a surface engageable with the back surface of the mirror. Springs are engagble with the spring seating surface and with the spring plate for exerting a resiliant biasing force on the mirror which is sufficiently large to force the mirror against the peripheral flange of the keeper when the mirror is not installed in a laser. The spring force is sufficiently small to permit the mirror to be moved out of contact with the peripheral flange and to a different location when the front surface of the mirror is engaged by mirror positioning structure of the laser in the course of installing the mirror mount in a laser.

Floating mirror mount

A method and apparatus for producing preferential polarization of the output light beam from a laser of the kind having a three surface retroreflector comprises mounting the three reflecting surfaces of the retroreflector so that the surfaces are orthogonal in the retroreflector. The preferential polarization is obtained by controlling the combined effects of the orientation of the retroreflector assembly, with respect to the axis of the beam, and the selection of the coatings on the three reflecting surfaces.

Cube corner polarizer

A fast axial flow folded laser includes a vessel which houses heat exchangers and a pump which imparts the pumping action throughout the laser. Only one housing is necessary and this housing can also be used as an optical bench for the resonator. In one embodiment a positive displacement rotary pump is utilized and a retroreflector included to mount three fold mirrors. In the folded configuration the retroreflector provides angular stability in any two orthogonal planes parallel to the laser beam.

A sealed rotary compressor is provided which includes separate pump and gear chambers. Disposed within the pump chamber is a set of rotors operatively associated with a set of gears rotatably mounted within the gear chamber. A substantially pressure differential exists between the two chambers. Rotational power is applied directly to the rotors through a static seal rather than through the gears which are utilized primarily to transmit the dynamic load. The pump chamber is defined by two end plates with a surrounding thin-walled housing. Within the pump chamber are interior thin wall members with the rotary members disposed therebetween and defining inlet and outlet pockets operatively associated with a pump housing inlet and outlet means. The combination of pump and gear chambers are disposed within a separate pressure vessel whereby gas is introduced through the pressure vessel into the pump chamber and is expelled from the pump chamber into the interior of the pressure vessel from where it is expelled to a desired apparatus. The present invention is particulary suitable for applications with CO.sub.2 axial-flow lasers.

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Sunnyvale, CA, United States of America

Dale E Koop