Kaptron, Inc.

Other

Becton Dickinson and Company Limited

Monsanto Research Corporation

Fred C Unterleitner

Narinder S Kapany

Shin-Lo Chia

An attenuating centrosymmetric reflective (CSR) device is provided for controllably coupling optical energy between pairs of optical fibers. The CSR-based attenuating device comprises a CSR coupler having a neutral density attenuating plate inserted between a fiber holder portion of the device and the reflecting mirror. The attenuating plate is preferably of variable density so that translation of the attenuating plate across the path of the beams results in varying attenuation. In a specific embodiment, back reflections to the source are eliminated by positioning the variable density attenuator plate at an angle large enough so that reflections of all reflected rays exceed the acceptance angle of the fiber ends. The variable density attenuating plate may be manually or automatically moved to obtain the desired attenuation.

Optical fiber coupler with attenuator

A fiber optic isolator uses only one-half the amount of costly rotator material as the prior art and an isolated laser amplifier uses only one-quarter the amount of costly rotator material. An embodiment of a fiber optic isolator includes a concave reflector and a fiber holder defining first and second fiber ports that register the respective ends of first and second fibers. A polarizer is located between the first port and the reflector, an analyzer is located between the second port and the reflector, and a Faraday rotator is disposed between the polarizer and analyzer on one side and the reflector on the other side. The polarizer and analyzer have their polarization axes at a relative angle of 45.degree. while the rotator is configured to provide a 22.5.degree. rotation. The port locations, the reflector, the polarizer, and the analyzer are configured so that light diverging from the end of the first fiber and entering the first port passes through the system and is imaged at the end of the second fiber, at least for one polarization component. At the same time, light that enters the second port is prevented from leaving the first port, regardless of the polarization mode.

Fiber optic isolater and amplifier

The present invention provides modules for interfacing optical fibers with very low light loss and with provision for monitoring of the optical signal. The modules according to the present invention are characterized by the precise tolerances required in high capacity optical communication systems and yet may be mass produced at reasonable costs. A device according to the present invention comprises an imaging element having a curved reflective surface at one end and prealigned fiber insertion holes at the other end. Various embodiments of the invention are disclosed.

Fiber optics communication modules

Multiple reflection modules having as a light source or a light target a lensed optical fiber employ one more spherical reflectors and wavelength selectors for selecting the wavelengths of optical radiation on selected optical paths between said light source and said light target. The reflection module may be a multiplexer or a laser cavity. As a laser, it may include as a source a semiconductor laser comprising a laser source disposed to direct radiation through a first multiple layer dielectric Fabry-Perot cavity with the center of curvature between the source and a fiber tip to which output energy is to be coupled, and a second reflector mounted behind the first reflector, the second reflector being a full reflector with the center of curvature at the laser source. The first reflector may have a narrow-band optical transmissivity characteristic intended to permit only a narrow band of optical radiation to be coupled to the full reflector, the full reflector disposed as a confocal relfective surface of the laser cavity. Reflections from the first reflector are coupled to a tip of an optical fiber. Other embodiments of the invention are configured as multiplexers. Still other embodiments employ a diffraction grating as part of a laser cavity or as a frequency-selective multiplexer.

Hybrid active devices coupled to fiber via spherical reflectors

A star coupler/monitor comprises a beam splitter (25) and at least one imaging element (30) oriented relative to first, second, and third spatially discrete regions (35a-c) as follows. A minor portion of the light emanating from any given point in the first region (35a) is imaged at a corresponding point in the second region (35b). A major portion of the light emanating from the given point is imaged at a corresponding point in the third region (35c). The ends of N input fibers in an input bundle (12) are registered in an array in the first region (35a). The ends of N monitor fibers in a monitor bundle (15) are registered fiber-by-fiber at optically conjugate locations in the second region (35b) so that a minor portion of the light emanating from any one of the input fibers is imaged at the corresponding monitor fiber end. An integrating element (17) such as a rod is disposed in the third region (35c). The method achieves registration simply and virtually automatically by forming both bundles in the first instance from a single bundle. The method comprises the steps of providing a plurality of fibers (76), reducing the cladding thickness over corresponding intermediate portions (77) of the fibers, bonding the intermediate portions of the fibers into a tight assembly (79), severing the assembly at an intermediate point to define two bundles, and locating the two bundles so formed at optically conjugate locations.

Star coupler for optical fibers

Apparatus and a manufacturing method for a star coupler/monitor (10). A star coupler/monitor comprises a beam splitter (25) and at least one imaging element (30) oriented relative to first, second, and third spatially discrete regions (35a-c) as follows. A minor portion of the light emanating from any given point in the first region (35a) is imaged at a corresponding point in the second region (35b). A major portion of the light emanating from the given point is imaged at a corresponding point in the third region (35c). The ends of N input fibers in an input bundle (12) are registered in an array in the first region (35a). The ends of N monitor fibers in a monitor bundle (15) are registered fiber-by-fiber at optically conjugate locations in the second region (35b) so that a minor portion of the light emanating from any one of the input fibers is imaged at the corresponding monitor fiber end. An integrating element (17) such as a rod is disposed in the third region (35c). The method achieves registration simply and virtually automatically by forming both bundles in the first instance from a single bundle. The method comprises the steps of providing a plurality of fibers (76), reducing the cladding thickness over corresponding intermediate portions (77) of the fibers, bonding (as for example by cementing or fusing) the intermediate portions of the fibers into a tight assemby (79), severing the assembly at an intermediate point to define two bundles, and locating the two bundles so formed at optically conjugate locations.

A flow cytometry apparatus comprises a nozzle for flowing particles in a stream of fluid. A source of light, such as from a laser, is adapted to direct a beam of light at the flowing particles. A beam focusing lens is positioned in the optical path of the light beam to provide an elliptical beam spot at the focal stream to thereby elongate the focal spot of the beam. One or more parameters of the particles in the stream related to light from the beam striking the particles is detected in the flow cytometry apparatus.

Light beam focal spot elongation in flow cytometry devices

A fiber optics coupler module has a portion defining a spherical reflective surface characterized by a self-conjugate plane having the property that a point source of light in the self-conjugate plane is imaged in the self-conjugate plane. The coupler includes first and second optical transceiver terminals adapted to register a source, detector, or fiber end at each of first and second conjugate locations within the self-conjugate plane. The reflective surface passes a fraction of light incident thereon, whereupon a portion of light diverging from the first location passes through the reflective surface along a first optical path. Similarly a portion of light diverging from the second location passes through the reflective surface along a second optical path. The coupler further includes focusing means on the side of the reflective surface remote from the first and second locations for imaging light travelling along the first optical path at a third location, and also for imaging light travelling along the second optical path at a fourth location. In a first series of embodiments, the reflective surface is partially transmissive, partially reflective for wavelengths in a given range. In a second series of embodiments, the reflective surface is a dichroic surface. In a third series of embodiments, the coupler uses a plane reflection grating and collimated light.

Fiber optics communications modules

The present invention provides modules for interfacing optical fibers with very low light loss and with provision for monitoring of the optical signal. The modules according to the present invention are characterized by the precise tolerances required in high capacity optical communication systems and yet may be mass produced at reasonable costs. A device according to the present invention comprises a transparent imaging element having a curved reflective surface at one end and prealigned fiber insertion holes at the other end. The transparent element is characterized by an index of refraction equal to that of the fiber core, and the fibers are glued in their respective holes with index matching cement.

An insulating window which has louvered radiant energy absorbing screen positioned in the airspace between inner and outer spaced apart window panes, said airspace connected at the top to electrically actuated dampers and blower in a duct system, and said airspace connected at the bottom to the interior of the room through an air filtering element. In the preferred embodiment, temperature sensors and electronic logic system provide control of air flow rate and valve settings to accomplish space heating, water heating and/or exterior venting of hot air as required by weather conditions and building heat demands.

See-through solar collector

A device useful as a detector for fluid (liquid or gas) chromatograph effluent comprising a light source, a cell divided into sample and reference fluid compartments separated by an opaque diaphragm sufficiently thin to form a Fraunhofer diffraction pattern, means to introduce and remove sample and reference fluids to and from said compartments, means to collimate light from said light source at said diaphragm and through the compartments of said cell, photodetector means capable of sensing phase shift of said diffraction pattern, and means to focus light exiting said compartments on said photodetector. When used as a detector for chromatograph effluent the sample compartment should have a volume less than the smallest volume of eluted fractions from the chromatograph with which the device is used. An especially significant and novel feature of the device is the cell used in the refractometer.

Diffractometric refractometer

Light from a bulb is projected through the microfiche transparency by a condensor and a projection lens system and the projected image therefrom is passed through a prism to viewing screen means. The prism has a flat or curved, transparent entrant surface for receiving the projected image, a flat, transparent exit surface facing the viewing screen means, a first, metal coated reflecting surface opposite to the entrant surface and forming a predetermined acute angle with the exit surface such that a major portion of the light beam passing through the entrant surface is reflected by the first reflecting surface to the exit surface at at incident angle greater than the critical angle for total internal reflection by the exit surface and a second, metal coated reflecting surface angularly facing the exit surface for returning the light beam reflected internally by the exit surface back to the exit surface at an incident angle which is less than the critical angle such that the returned light beam passes through the exit surface to impinge on the viewing screen means. In one preferred embodiment the prism further includes a third, metal coated reflecting surface which is co-planar with the exit surface for receiving a minor portion of the light beam reflected by the first reflecting surface and for reflecting it to tne second reflecting surface.

Prism reflector for optical projector/reader

Light from a bulb is projected through the microfiche transparency by a condensor and a projection lens system and the projected image therefrom is passed through a prism to viewing screen means. The prism has a flat or curved, transparent entrant surface for receiving the projected image, a flat, transparent exit surface facing the viewing screen means, a first, metal coated reflecting surface opposite to the entrant surface and forming a predetermined acute angle with the exit surface such that a major portion of the light beam passing through the entrant surface is reflected by the first reflecting surface to the exit surface at an incident angle greater than the critical angle for total internal reflection by the exit surface and a second, metal coated reflecting surface angularly facing the exit surface for returning the light beam reflected internally by the exit surface back to the exit surface at an incident angle which is less than the critical angle such that the returned light beam passes through the exit surface to impinge on the viewing screen means.

Growing community of inventors

Palo Alto, CA, United States of America

Fred C Unterleitner