Abstract: An optical pattern generator uses a rotating component that includes a number of deflection sectors containing optical elements. Each sector deflects an incident optical beam by a substantially constant angle although this angle may vary from one sector to the next. The constant deflection angle is achieved by symmetry within the deflection sector, specifically gut-ray symmetry. The rotating component may be combined with an imaging group that produces, for example, image points, spots, or lines displaced along a line locus. The image spots can also be displaced to either side of a line, for example by introducing a tilt in the orthogonal direction or by introducing light beams at various angles to the plane of symmetry.

Abstract: A fractional treatment system can be configured with a laser wavelength that is selected such that absorption of the laser wavelength within the tissue increases as the tissue is heated by the laser (e.g., 1390-1425 nm). Desirably, the laser wavelength is primarily absorbed within a treated region of skin by water and has a thermally adjusted absorption coefficient within the range of about 8 cm?1 to about 30 cm?1. An adjustable mechanism can be used to adjust the beam shape, beam numerical aperture, beam focus depth, and/or beam size to affect the treatment depth and or the character of the resulting lesions. The system may be designed to be switchable between a treatment mode that is semi-ablative and a treatment mode that is not semi-ablative. Adjustment of these parameters can improve the efficiency and efficacy of treatment.

Abstract: In a fractional treatment system, an adjustable mechanism can be used to adjust the beam shape, beam numerical aperture, beam focus depth, and/or beam size to affect the treatment depth and or the character of the resulting lesions. Adjustment of these parameters can improve the efficiency and efficacy of treatment. Illustrative examples of adjustable mechanisms include a set of spacers of different lengths, a rotatable turret with lens elements of different focal distances, an optical zoom lens, and a mechanical adjustment apparatus for adjusting the spacing between two optical lens elements. In one aspect, the fractional treatment is configured with a laser wavelength that is selected such that absorption of the laser wavelength within the tissue decreases as the tissue is heated by the laser (e.g., 1480-1640 nm).

Abstract: A system, apparatus, and method may provide laser beams of two or more wavelengths from diode pumped solid-state laser sources (220, 222, 224). The beam paths of these laser beams with different wavelengths, which are generated by the laser sources (220, 222, 224), may be aligned along a common optical axis 280 by an optical configuration, to treat at least one target area. Frequency-doubled laser beams, output from a plurality of diode pumped solid state laser cavities, may be passed through fold mirrors (M2, M5, M8), and combined on a common optical axis 280, using one or more combiner mirrors (M10, M11, M12), to unify the beam paths. Selected laser beams may be delivered to a target using one or more delivery systems.

Abstract: An arrangement for monitoring the power delivered by a photon channeling element including an integrating chamber to receive an output end of the photon channeling element and an optical surface positioned to reflect a portion of the laser-light exiting the photon channeling element at substantially normal incidence to the beam centerline. The integrating chamber may be adapted to collect substantially all of the laser-light reflected from the optical surface. The arrangement may also include a sensor in optical contact with a portion of the integrating chamber that is out of the path of laser-light reflected from the optical surface.

Abstract: An arrangement for monitoring the power delivered by a photon channeling element including an integrating chamber to receive an output end of the photon channeling element and an optical surface positioned to reflect a portion of the laser-light exiting the photon channeling element at substantially normal incidence to the beam centerline. The integrating chamber may be adapted to collect substantially all of the laser-light reflected from the optical surface. The arrangement may also include a sensor in optical contact with a portion of the integrating chamber that is out of the path of laser-light reflected from the optical surface.

Abstract: An illumination system includes a multimode diode-laser and two optical fibers. Light from the diode-laser is directed into the first optical fiber having a first core diameter. The light exits the first optical fiber and is directed by an optical system into a second optical fiber having a core diameter greater than the first optical fiber and a numerical aperture greater than the numerical aperture of the optical system. A light beam exiting the second optical fiber has an intensity distribution having sharp edges and uniformity better than plus or minus ten percent over a central ninety percent of the beam.

Abstract: Typically, a laser emits significant energy after a control signal is generated to disable the power supply. The inherent delay between generation of a control signal for shutting off a laser power supply and actual termination of an output beam pulse in response to the control signal, is compensated in the context that the control signal is generated automatically upon coincidence of measured output beam power with a preset threshold value. Power supplied to a laser is modulated to cause generation of a pulsed laser output beam. The cumulative energy of each output beam pulse is monitored and a feedback signal indicative of measured output beam pulse energy is supplied to the power supply. The feedback signal is compared with a user-selected threshold value, and a control signal is generated for terminating the output beam pulse (by terminating input power to the laser) when the measured output pulse energy reaches the threshold value.

Abstract: 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.

Abstract: A contact lens for viewing the interior of a patient's eye during an argon laser trabeculoplasty (ALT) procedure and for delivering laser energy to desired regions of the trabecular meshwork of the eye. The contact lens is fabricated from a hollow plastic body which is filled with a medium having an index of refraction which is substantially the same as that of the aqueous humor within a patient's eye. Visible and laser light enter the lens by means of a thin window of substantially uniform thickness and exit the lens (thereby entering the eye) at a front face of substantially uniform thickness whose outer curvature is approximately the same as that of the patient's eye. The degree of astigmatic focusing which normally occurs as the visible light and laser beam pass through the contact lens and cornea and into the aqueous humor is substantially reduced.

Abstract: There are disclosed an improved method and apparatus which derive the optical characteristics of a lens system from a plurality of measurement beams and can display the same. Included is an imaging channel which cooperates with a microprocessor for detecting the measurement beams and processing the detected beam information to derive the optical characteristics of the lens system.

Abstract: An apparatus for delivering a defocused laser beam to a sharp-edged spot (having variable size) in a target plane. The beam has a low power density in a plane of interest between the delivery apparatus and the target plane. In a preferred embodiment, the target plane is the retina of a patient's eye, and the defocused beam profile is controlled so that the beam has low power density at the eye's cornea. The beam produced by the invention is useful not only for ophthalmic surgery, but also for industrial laser heat treating and cutting applications in which a sharp-edged beam cross-section is needed at a target, particularly where delivery of low beam power densities at non-target structures are desirable. In a preferred embodiment of the inventive apparatus, an input laser beam emerges from an optical fiber, and a first lens (having short focal length) is mounted adjacent the optical fiber's output end to receive and transform the input beam.

Abstract: 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, and wherein the other mode varies the size of the spot at the retina by altering it focal point.

Abstract: 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 seletively passing the beam. Preferably, one of the appertures has a pair of 45.degree. knife edges (40, 42). The transmission of the beam past the knife edge is monitored by a detector (30). In operation, the lens focal position is varied while the transmission of the beam past the knife edge is monitored in order to locate and measure the diameter of the transformed waist. The diameter of the beam at one other known location is measured. A processor then calculates beam quality by fitting these measurements to a mathematical model.

Abstract: A radial keratotomy knife which includes an accurate linear position transducer for digitally displaying the extension of a surgical blade beyond a footplate on the knife. A system is also disclosed for zeroing the blade position relative to the footplate. The system includes a zeroing sleeve having a reflective membrane to reflect light to a detector. The knife is inserted into the sleeve so that the footplate is in contact with the membrane within the system contained within a console. When the blade is advanced to contact the reflective membrane from within the sleeve, the reflected light pattern is altered to establish accurately a zero position of the knife blade relative to the footplate. The knife is then withdrawn from the sleeve and the blade advanced by a micrometer so that the transducer produces a signal relative to the reference level indicating the extension of the blade.

Abstract: A micromanipulator for an instrument for focusing a beam of light on a target, such as a laser in an ophthalmic instrument, includes a control member coupled through a spherical bearing located at a pivot location to a coiled spring connected to a control rod for manipulating the focus of a gimballed beamsplitter in the x and y directions. The components are structured and arranged to lie on an axis in the neutral position so that the movement of the light beam, during focusing, corresponds directly to the direction of movement of the control member by an operator. The coiled spring acts as an automatic centering device to return the focused light beam to a predetermined position in the absence of manipulation.

Abstract: A variable spot size illuminator for projecting a variable size spot of light into an illumination plane comprises a source of light, fiberoptic image transmission means having an entrance surface and an exit surface, means for projecting a cone of said light onto said entrance surface, objective lens means for focusing light emerging from said exit surface into said illumination plane, and means for varying the distance between said entrance surface and the vertex of said cone of light. The variable spot size illuminator is useful for projecting a spot of variable size with constant beam convergence in a laser photocoagulator.