摘要:
A method for the selective removal of corneal tissue, and change of curvature thereof, for refractive vision correction, by means of a correction template in conjunction with a planar cutting high pressure water jet micro-keratome. The correction template is adapted to provide a planar cutting guide, on the corneal tissue, for the refractive correction required, with the template being shaped with a non-planar surface of predetermined configuration (related to the desired correction). The non-planar surface of the template is fitted to the area of the cornea to be refractively corrected, whereby the corneal tissue to be removed is selectively deformed so as to be substantially conformed to and held against the non-planar surface. Application of a vacuum between the template and cornea aids in this holding. The water jet micro-keratome, in a sheet-like configuration provides a full non-scanning transverse planar cut through the corneal tissue at a position adjacent the template, such that release of the template from the corneal tissue results in the undeformed configuration thereof having the desired correction. Use of the water jet micro-keratome provides a cut corneal tissue surface of smoothness and polish, substantially equivalent to that of the original surface.
摘要:
A method and device for highly accurate corneal topographical mapping and a device for effecting the mapping for use in effecting vision correction by removal of corneal tissue. The method and device involve use of a modified optical interferometer with directing of a coherent light beam, such as from a laser, to the anterior surface of a cornea; splitting the beam so that half the beam is directed to a reference object having a predetermined shape; capturing the reflected light from the cornea and the reference object so as to form an interference pattern; and using the interference pattern to determine deviations or displacements of the corneal surface from the known reference shape. The deviations are then utilized in corneal tissue removing procedures, such as RK, PRK and RLK, by determination of the extent and position of tissue removal. With a modified RLK procedure, the deviations are used in preparing an appropriate corneal template for use with a keratome using a high speed water jet as the cutting means.
摘要:
An alignment fixture includes an optical bench 12 mounting a semiconductor laser 21, a monitor 23 of optical emission, a lens 27 focused for transmitting optical emission along an optical axis 43, a holder 26 mounting the lens 27, a pedestal 36 positioning a diaphragm 29 spaced for the lens 27, an optical fiber 45, a tube 49 surrounding the fiber 45 and joined to the fiber 45, a bushing 55 surrounding the tube 49 and joined to the optical bench 12, and a datum surface 16' on the bench 12 for aligning the lens 27 and the fiber 45 with the optical axis 43.
摘要:
A mechanism for achieving single frequency output in a semiconductor laser diode is disclosed. In accordance with the invention, a conventional laser diode having an anti-reflection coating on its output facet is coupled to a single mode fiber output pigtail having an anti-reflection coating on its input facet. The anti-reflection coatings suppress Fabry-Perot type feedback which would normally be effective for a large number of wavelengths. The fiber includes a built-in distributed Bragg reflector grating, which grating is located just beyond the output fiber input facet. The grating supplies feedback that is effective only over a narrow wavelength band approximating the wavelength spacing between the actual longitudinal modes of the structure so that the laser produces only a single frequency output.
摘要:
In contrast to existing light addressed light valves for projection displays which use a homogeneous CdS or Se photoconductive layer as the control element for a liquid crystal cell, a silicon photo-diode array is disclosed which makes an effective control element capable of applying a spatially varying AC voltage across a liquid crystal light valve. Writing may be done with a miniature CRT in an optical or electron excitation mode. It is shown that for a video mode the ratio of diode capacitance to liquid crystal cell capacitance associated with the diode, and the frequency of the applied square wave voltage, define the buildup or decay time of the liquid crystal cell voltage. Thus, the frequency of the applied AC voltage can be used to control sensitivity and transient response and there is no lag. The dynamic range of the cell voltage is shown to depend on the ratio of diode capacitance to liquid crystal cell capacitance. The display can be used in a storage mode by erasing with an AC voltage and writing with a constant voltage. The silicon photodiode array is compatible with a CCD frame store using direct minority carrer injection for writing. This light addressed version thus represents a desirable milestone in achieving an all solid-state projection display.
摘要:
A read/write system is disclosed for optical disc apparatus. The light source is removed from the head and optically coupled to the disc by a single-mode fiber which acts as a spatial filter. Adverse effects on the light source due to reflection from the disc are avoided by making the fiber length greater than one-half the coherence length of the source. A sparing switch and combiner component may be included in the system. An array of discrete light sources, each coupled to an associated fiber, may also be employed for multiple track accessing.
摘要:
A semiconductor heterojunction optical loss modulator section (30), having an anti-reflection coating (52) on its optical output beam facet (32), is located with an opposite facet (31) optically coupled to, and closely spaced from, a semiconductor heterojunction laser section (20) having substantially the same cross-section structure as the loss modulator section (30). The laser section is operated CW in a single mode. In this way, the output beam (50) emanating from the laser section (20) and passing through the anti-reflection coating (52) can be coupled into an optical fiber (60) for transmission purposes. This output beam (50) is substantially single frequency and is intensity modulated, in a signal-pattern independent fashion, in accordance with an electrical signal applied to the loss modulator section (30).
摘要:
The invention is a matrixing system, involving optical fibers, for accessing data encoded on an optical disk. Illustratively, a plurality of first fiber bundles couples optical sources to disk locations along angular coordinates, and a plurality of second fiber bundles couples disk locations along radial coordinates to optical detectors. Selective activation of a particular source and particular detector enables a predetermined disk location to be read. The system is characterized by a random access time on the order of 100 .mu.s or less.
摘要:
Disclosed are a germicidal system and method for deactivating pathogens on the surface of a bodily extremity protected by a prophylactic covering substantially opaque to UV-C radiation. The device includes an enclosure having one or more openings through which the extremity can be inserted. The enclosure contains a radiation source configured to produce germicidal radiation having a wavelength of about 253.7 nm. The openings are configured relative to the radiation source such that the inserted extremity is in close proximity to the radiation source. The prophylactic covered extremity is preferably a gloved hand thereby sanitizing the surface of the glove. The extremity inserted is preferably exposed for a predetermined period of time to ensure a desired level of sanitization. Optionally, the device can include detectors to determine the position of the hand, the spread of the fingers, and whether the hand is covered by a glove.
摘要:
A method and system for sterilizing an item using ozone and a secondary molecule is provided. The secondary molecule comprises hydrogen for conversion to a hydroxyl radical. The item and secondary molecular are inserted into a container, and a gaseous mixture containing ozone can be inserted into the container by way of a filling station having an ozone source and a vacuum pump to remove air from the container. Sterilization occurs within the container such that the container can be removed from the filling station. A preferred secondary molecule is an alcohol, such as isopropyl alcohol. Prior to insertion of the item into the container, the item can be soaked in a nutrient rich hot water bath at or near boiling and optionally at a pressure above atmospheric to assist in sterilization.