General Electric Company

The Schepens Eye Research Institute, Inc.

Schepens Eye Research Foundation

Carl M Penney

Robert H Webb

Michael H McLaughlin

Sandra F Feldman

Keith P Thompson

Carl Edward Erikson

Stephen A Burns

Bradley S Thomas

Jerome Johnson Tiemann

Marshall Gordon Jones

Nelson R Corby, Jr

Angel L Ortiz, Jr

Sudhir D Savkar

Robert D Lillquist

Robert E Sundell

Tushar S Chande

Allen W Case, Jr

Joseph P Chernoch

Richard M Lund

Marshall Lapp

Robert N Roy

Nelson R Corby Jr

Nancy H Irwin

A refractometer provides a reference path coaxial with a measurement path and thereby simplifies construction by reducing the number of parts and simplifies maintenance by halving the number of optical axes to be aligned. The refractometer includes a reference projector for projecting a reference pattern on a reference pattern position on a detector during a reference interval, a site-selector for selecting a measurement site on an optical system, and a measurement projector for projecting a measurement pattern through this selected measurement site and onto a measurement pattern position on the detector during a measurement interval. The reference projector, the site selector, and the measurement projector are all aligned along the same optical axis. In the case in which the optical system is a human eye, the designated site in typically a site on the cornea and the detector is the retina of the eye. The refractometer provides an aligner for aligning the reference pattern position with a measurement pattern position. The amount by which these two positions are moved in order to achieve alignment provides a measure of the optimal wavefront corresponding to the measurement site.

Coaxial spatially resolved refractometer

A refractometer provides a reference path coaxial with a measurement path and thereby simplifies construction by reducing the number of parts and simplifies maintenance by halving the number of optical axes to be aligned. The refractometer includes a reference projector for projecting a reference pattern on a reference pattern position on a detector during a reference interval, a site-selector for selecting a measurement site on an optical system, and a measurement projector for projecting a measurement pattern through this selected measurement site and onto a measurement pattern position on the detector during a measurement interval. The reference projector, the site selector, and the measurement projector are all aligned along the same optical axis. In the case in which the optical system is a human eye, the designated site in typically a site on the cornea and the detector is the retina of the eye. The refractometer provides an aligner for alignining the reference pattern position with a measurement pattern position. The amount by which these two positions are moved in order to achive alignment provides a measure of the optimal wavefront corresponding to the measurement site.

A probe is configured for measuring color in a sample of material having a refractive index. The probe includes a light source that emits a light beam toward the sample. A color sensor is disposed at an oblique angle with the light source and directed toward a common probe zone for containing the sample. The light source and sensor are optically aligned with a reference plane in the probe zone to effect angles of incidence and reflection relative to the zone having a magnitude substantially equal to Brewster's maximum polarization angle for the refractive index of the sample, for measuring interior color of the sample.

Internal color probe

This invention relates to the modification of lasing medium surfaces, such as crystals, to reduce the internal reflections that contribute to amplified spontaneous emission (ASE) losses. A laser ablation treatment involves focusing an optical irradiation means on a target surface having desired ablation pattern and ablating the target surface according to the selected ablation pattern. A cross-hatch pattern on the target surface is secured by the target surface being mounted onto a precision motor driven translation stage and stepped throughout the desired ablation pattern. The optical irradiation means are oriented initially at 45.degree. to the target surface length and subsequently rotated by 90.degree..

Lasing medium surface modification

An imaging system responsive to focused laser light includes a focusing lens for focusing the laser light and a mirror having a reflective side, a non-reflective side, and a hole for passing a predetermined portion of the laser light from the focusing lens through the non-reflective side. A fiber probe excites and couples fluorescence from an analyte. The fiber probe has a fiber front face for receiving laser light through the hole and for directing the fluorescence to the reflective side of the mirror. Optical devices for imaging the portion of the fluorescence reflected by the mirror to form an image of the fiber front face are provided, as well as an optical stop having an aperture in the image plane of the imaging means for reducing undesired light from the imaging means before reaching a detector. The mirror is angled for directing substantially all fluorescence from the the fiber probe into the imaging means rather than back toward the fiber probe.

Optical system for detection of signal in fluorescent immunoassay

A spatially resolved map of the eye's refractive characteristics are provided by measuring the eye's refractive characteristics on a point-by-point basis across the anterior surface of the eye. This spatially resolved refraction data may be obtained subjectively by providing a reference pattern and a measurement beam, by establishing a particular position on the cornea as the location to be measured and manipulating the orientation of the measurement beam at that measurement point to bring the measurement beam to a desired position relative to the reference image. When the patient indicates that the measurement beam is in the desired position relative to the reference pattern, the orientation of the beam is recorded as the refractive data for that measurement point and the process proceeds to another measurement point. This provides relatively rapid, physiologically accurate refractive data on a spatially resolved basis. Alternatively, this spatially resolved refraction data may be obtained objectively by independently controlling the position and orientation of a measurement beam and using a feedback null system to determine the refractive characteristics. This enables rapid, automatic non-subjective determination of the refractive characteristics of the eye and thereby provides the ability to provide improved correction of the eye. This spatially resolved refraction information enables spatially resolved correction of vision by spatially resolved shaping of the anterior surface of the eye.

Spatially resolved objective autorefractometer

Eye alignment is determined by producing a combined iris/retinal image by use of an imaging system. The relative position of the centroid of the pupil and various structures on the retina is indicative of the eye alignment. The eye alignment may be determined by comparing a combined iris/retinal image at the present time with a stored iris/retinal image at a past time. The imaging system may be a laser scanning ophthalmoscope.

Objective eye alignment measurement method and system

An alignment system for use with a keratoscope to form an eye measurement system uses a source of a light beam which is directed towards a cornea. A reflection from that beam is supplied to first and second quadrant detectors which are connected to circuits to generate an output when the cornea is properly aligned. Upon proper alignment, the system triggers the calculation of the cornea shape by the keratoscope.

Alignment system for keratograph

A hologram is used to project an image of a pattern similar to a placido upon the cornea of a subject. By viewing the reflection of the pattern in the subject's cornea, one may measure the curvature of the cornea. The use of the hologram in the keratometer system allows the pattern to be imaged at infinity, thereby minimizing any error which might otherwise result from incorrect assumptions about the cornea position.

Keratographic instrument using holographic placido illuminator to reduce

An apparatus for producing a tape superconductor of a compound superconductor type wherein the apparatus includes a first wire constructed of the superconducting compound material which is melted to form a bead. The bead is then wiped on a tape substrate to form a layer as the substrate is fed by the bead. Finally, the layer is cooled and a tape superconductor is formed.

Apparatus for making A-15 type tape superconductors which includes means

An input/output port for a lasing medium to minimize wavefront distortion of a coherent light beam is described. The input/output port includes an end surface integral the medium and a first port surface integral the end surface. The first port surface is substantially perpendicular to a plane normal to the longitudinal axis extending through the medium so that each ray of a beam of coherent electromagnetic radiation lying in a plane of a thickness of the beam may impinge on the port surface at a substantially equal angle with respect to reference planes normal to the port surface at the points of impingement.

Input/output ports for a lasing medium

The temperature of a surface undergoing a radiation assisted thermally driven process is sensed by observation of the thermal emission from that surface and used to control the process. In a preferred embodiment, the blue edge of the thermal emission spectral distribution is detected to determine the surface temperature of a workpiece during a process such as laser-assisted chemical vapor deposition, and used to control this temperature. The temperature measuring system has means for focusing workpiece thermal emission and defining the field of view, a spectrometer to separate shorter wavelength light from other spectral components of the thermal emission, and a photon-counting system to detect the shorter wavelength light and generate a surface temperature signal. Systems to determine surface temperature at a spot and along a line have an optical prism to disperse the thermal emission into component wavelengths, and a multichannel photon-counting detector comprised of an intensified photodetector array.

Temperature measurement and control for photohermal processes

A laser peening apparatus and method for peening a workpiece utilizing a laser beam is described. The system includes a foil aligned with a surface of the workpiece to be peened and lasing the aligned foil surface. The foil absorbs energy from the beam and a portion of the foil vaporizes, which creates a hot plasma within the foil. The plasma creates a shock wave which passes through the foil and peens the workpiece surface.

Laser peening system and method

The wetting angle of a bead, such as a welding bead, is detected and controlled by a feedback operation. In particular, one or more optical profiler heads are used to detect the wetting angle along the edge of a bead. If the wetting angles differ from a preferred value, a feedback control system adjusts one or more weld parameters in order to bring the wetting angles to a desired value. If the wetting angle obtains a value which makes the weld joint completely unacceptable, an alarm condition may be activated. The detection of the bead wetting angles may be provided by two optical profiler heads, each head tracking a corresponding one of the edges or sides of the bead so as to provide information from which a corresponding wetting angle may be obtained.

Weld bead wetting angle detection and control

Multiple light detection channels are introduced into a flying spot optical triangulation ranging system to increase the speed of acquiring range values. A laser beam is rapidly swept across a surface by a beam deflector. Each fiber optic channel can receive light only from a different point along a line at the intersection of the swept beam with the surface. The receiver channels are duplicated and separate detectors generate signal pulses at times that are a function of range to the surface. These are processed in parallel to calculate N range values per beam sweep, where N is the number of channels.

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Saratoga Springs, NY, United States of America

Carl M Penney