Method and apparatus for supplying pulsed power to an ophthalmic laser system
Granted: January 18, 1994
Patent Number:
5280536
A laser power supply including circuitry for converting standard, 115-120 volt, AC power from a wall outlet to current pulses for powering a laser, to generate a pulsed laser output beam having laser pulse amplitude and duration matching pre-selected parameters. In a preferred embodiment, the invention powers an argon laser tube and generates output laser beam pulses having power in the range from about 50 milliwatts to 2 watts, and duration in the range from about 0.01 second to 2…
Apparatus for measuring the mode quality of a laser beam
Granted: November 30, 1993
Patent Number:
5267012
A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (34) having apertures (36,38) for selectively passing the beam. Preferably, one of the apertures has a pair of 45.degree. knife…
Fiber optic handpiece
Granted: November 9, 1993
Patent Number:
D341200
Contact laser delivery probe
Granted: November 2, 1993
Patent Number:
5257989
A method and apparatus for minimizing damage to an optical fiber used as part of a laser radiation delivery system are disclosed. The apparatus includes the use of a spacer positioned adjacent the tip of the fiber to minimize the impact on the fiber tip of debris and vapor generated by exposure of a tissue target to high energy radiation. The end of the apparatus is configured to vent debris and vapor from the end of the tip to reduce damage. The fiber tip may also be annealed to enhance…
Micromanipulator apparatus for surgical laser
Granted: November 2, 1993
Patent Number:
5257992
An improved apparatus for manually manipulating a surgical laser beam is disclosed. The preferred embodiment of the invention includes a mirror nominally positioned at a 45 degree angle to the incident laser beam, a joy stick for manipulating the mirror, and a linkage interconnecting the two. The mirror is mounted to allow it to rotate about two mutually perpendicular and intersecting axes. The linkage operates to direct the reflected laser beam in two orthogonal dimensions such that a…
Medical laser delivery system with internally reflecting probe and method
Granted: October 19, 1993
Patent Number:
5254114
A medical laser delivery system is disclosed which includes a laser generating a high power, pulsed, treatment beam. The beam is coupled to an optical fiber which is placed adjacent to a tissue site immersed in a fluid medium. The wavelength of the laser light and the energy of the pulses is selected so that the fluid medium will be quickly vaporized creating a vapor bubble around the end of the fiber. The end surface of the fiber is angled in a manner such that after the vapor bubble is…
Self-balancing hybrid using digitally programmable attenuator for variable impedance elements
Granted: September 28, 1993
Patent Number:
5249225
A digitally programmable attenuator balances impedance across a two to four-wire hybrid to reduce echo. The hybrid can interface a two-wire bi-directional telephone line, used for both transmit and receive signals with four-wire circuits having separate unidirectional transmit and receive signal paths. The four-wire circuit interfaces the two-wire circuit through a transformer. Optimum isolation is obtained by setting impedance Z.sub.BAL equal to the impedance of the line including the…
Alignment tool for endoscopes
Granted: September 7, 1993
Patent Number:
5243399
A tool is disclosed for evaluating the alignment of the channel of an endoscope. The tool includes a housing with one end thereof being connectable to the endoscope. The other end of the housing includes an eyepiece. A lens system is provided within the housing for imaging the distal end of the endoscope onto a reticle. The position of the image on the reticle allows the axial alignment of the endoscope channel to be evaluated.
RF excited CO.sub.2 slab waveguide laser
Granted: August 17, 1993
Patent Number:
5237580
A CO.sub.2 slab waveguide laser (10) is disclosed including a pair of spaced apart electrodes (36,38) having opposed light reflecting surfaces. The electrodes are dimensioned in a manner to guide light in a plane perpendicular to the reflecting surfaces. Light parallel to the reflecting surfaces is not constrained other than by the resonator mirrors (30,32). The resonator structure includes a negative branch unstable resonator in the nonwaveguide dimension. A stable resonator is used in…
Cavity mirror for suppressing high gain laser wavelengths
Granted: July 6, 1993
Patent Number:
5226054
A wedge mirror is disclosed for suppressing the high gain wavelengths in a laser. The mirror is provided with a pair of opposed surfaces lying in nonparallel planes. Each of the surfaces is provided with a wavelength selective coating. The coating on the surface of the mirror facing the gain medium is highly reflective of the high gain wavelength and highly transmissive of the low gain wavelength. This surface is oriented so that the light from the high gain wavelength is reflected out…
DC-to-DC converter using SCRS with natural commutation
Granted: June 1, 1993
Patent Number:
5216683
A DC-to-DC converter using an SCR bridge receives a first DC power signal and generates a current pulse train in response thereto. The current pulse train is supplied to a rectifying bridge which generates the second DC power signal in response thereto. A single capacitor means is placed between the leads of the output rectifier bridge to aid the commutation of the SCR bridge.
Method for remote power fail detection and maintaining continuous operation for data and voice devices operating over local loops
Granted: June 1, 1993
Patent Number:
5216704
First and second ISDN modems are disposed at a subscriber location and telephone system central office and are arranged to operate in a normal mode, and in a bypass mode upon power failure at the subscriber location. The modems are coupled through the telephone lines via interface transformers having centertaps. The centertap at the subscriber location is split and coupled to a sealing current source and that at the central office is coupled to a sealing current detector and ground.…
Slab laser with enhanced lifetime
Granted: June 1, 1993
Patent Number:
5216689
A CO.sub.2 slab laser is disclosed having a pair of spaced apart electrodes defining a rectangular discharge region. RF energy is fed through the electrodes to excite the CO.sub.2 gas. A pair of mirrors are located adjacent the electrodes to define the resonant cavity. A recombinant surface is placed between the ends of the electrodes and the mirrors to quench oxidizing species generated by the discharge before they reach the mirrors. In this manner, the degradation of the mirrors is…
Apparatus for measuring the mode quality of a laser beam
Granted: May 25, 1993
Patent Number:
5214485
A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (34) having apertures (36,38) for selectively passing the beam. Preferably, one of the apertures has a pair of 45.degree. knife…
Laser cathode voltage controller
Granted: April 27, 1993
Patent Number:
5206870
A voltage controller for converting AC line voltage (which may fluctuate, or vary from site to site) to AC power (having substantially constant average power) for a laser tube cathode heater. The voltage controller of the invention receives standard AC line voltage and a feedback signal proportional to the voltage applied to the cathode of a laser gas tube by the cathode heater. In a preferred embodiment, the feedback signal is processed to generate a DC signal representing time-averaged…
System for automatically adjusting the GVD of a Gires-Tournois interferometer
Granted: December 22, 1992
Patent Number:
5173908
A system is described for automatically maintaining the group velocity dispersion (GVD) of a Gires-Tournois interferometer (GTI) as the wavelength of incident light is varied. In the system, the transmission through the GTI is monitored by a photodiode as the wavelength is varied. The transmission through the GTI provides a measure of its GVD. Thus, the output of the photodiode can be used as a control signal for adjusting the GTI in a manner to maintain its GVD at the desired level. The…
Combination lens system for retinal photocoagulator laser system
Granted: December 15, 1992
Patent Number:
5171242
A novel retinal photocoagulator is described, having a laser for generating a beam of laser radiation and a beam delivery system for delivering the laser beam to the surface of the retina. The delivery system includes a lens system for varying the spot size of the beam at the surface of the retina which is operable in two alternate modes over a given range of spot sizes, wherein one of the modes varies the size of the spot while maintaining the beam in a focused condition at the retina,…
Laser resonator assembly
Granted: December 8, 1992
Patent Number:
5170409
A resonator assembly particularly suited for a diode pumped solid state laser is disclosed. The assembly includes a glass planar support plate 20. At least two transparent mirror mounts 26, 28 are bonded to the plate using a UV curable adhesive. The resonator mirros 22, 24 are in turn bonded to the mounts using a similar adhesive. The structure is easy to align and assemble and is low in cost. In addition, the assembly can be formed from materials having a low coefficient of thermal…
Dual actuation photoelectric foot switch
Granted: November 24, 1992
Patent Number:
5166513
A dual actuation foot switch particularly suited to medical laser systems is disclosed. The foot switch includes a housing having an opening for receiving a foot. A first switch is provided which is actuated by the placement of the foot into the housing. A second switch is actuated by pressure from the user's foot. The dual actuation feature can be used to initiate two different responses from the medical laser system.
Birefringent filter for use in a tunable pulsed laser cavity
Granted: November 17, 1992
Patent Number:
5164946
A birefringent filter ("BRF") unit, for use in the cavity of a tunable pulsed laser generating ultrashort pulses, including means for suppressing satellite pulses resulting from surface reflections. In one preferred embodiment, the inventive BRF has substantially parallel front and back surfaces, and is cut so that its optical axis is not parallel to its front surface. For example, the inventive BRF may be a quartz crystal having a thickness of 3 mm, with its optical axis oriented at an…
