Cogent Light Technologies, Inc.

C. R. Bard, Inc.

Glenn S Baker

Douglas M Brenner

Karlheinz Strobl

Robert L Piccioni

Edward L Sinofsky

Robert Fischer

Michael Thomas

David D Chang

Kenneth K Li

Zafirios Gourgouliatos

Fred P Paulino

Michael Madden

Michael G Dumont

Norman E Farr

An electromagnetic radiation source, such as an arc lamp, is located at a point displaced from the optical axis of a concave toroidal reflecting surface. The concave primary reflector focuses the radiation from the source at an off-axis image point that is displaced from the optical axis. The use of a toroidal reflecting surface enhances the collection efficiency into a small target, such as an optical fiber, relative to a spherical reflecting surface by substantially reducing aberrations caused by the off-axis geometry. A second concave reflector is placed opposite to the first reflector to enhance further the total flux collected by a small target. In accordance with one embodiment, the present invention is directed to devices in which the square of the off-axis distance divided by the radius of curvature is equal to or less than the extent of the source of electromagnetic radiation (y,/r&lE;s,).

Concentrating and collecting optical system using concave toroidal reflectors

An electromagnetic radiation source, such as an arc lamp, is located at a point displaced from the optical axis of a concave toroidal reflecting surface. The concave primary reflector focuses the radiation from the source at an off-axis image point that is displaced from the optical axis. The use of a toroidal reflecting surface enhances the collection efficiency into a small target, such as an optical fiber, relative to a spherical reflecting surface by substantially reducing aberrations caused by the off-axis geometry. A second concave reflector is placed opposite to the first reflector to enhance further the total flux collected by a small target.

Concentrating and collecting optical system using concave toroidal

The present invention provides a variable attenuator for an optical transmission system having a disc-like masking plate with apertures (or image zones) formed in an arcuate control area at the periphery of the plate. Within each aperture, at least one opaque masking member is provided extending outward from the origin to the perimeter of the aperture and having a masking surface with an incremental masking area which continuously increases in magnitude with increasing radial length of the aperture. The perpendicular cross-section of each masking member with respect to the optical axis preferably forms a geometric shape having straight-line edges extending radially outward from the origin of the aperture. In the preferred embodiment, a plurality of masking members are utilized (as a pair or sets of pairs). The disc-like masking plate is inserted perpendicularly into the path of the light beam such that the optical axis of the light beam defines a movement axis about the periphery of the masking plate upon which the origin of each aperture is placed. In this manner, rotation of the masking plate around its center provides discrete levels of attenuation of the light beam as successive apertures are placed in the path of the light beam. Several alternate embodiment enable gradual adjustment of the level of attenuation using a plurality of masking plates each having a single aperture with at least one masking member disposed therein. In these embodiments, the masking plates are disposed perpendicularly at predetermined intervals along the optical axis of the light beam and are independently rotated about the optical axis so as to vary the total masked area of the light beam's spot image by overlapping of the masking members.

Light intensity attenuator for optical transmission systems

The present invention comprises a system for condensing and collecting electromagnetic radiation having a primary reflector disposed on one side of an electromagnetic radiation source and a target disposed on the opposite side of the source. The primary reflector includes a concave reflecting surface portion, which preferably forms the entire surface of the reflector. The concave surface portion of the primary reflector, which is preferably of a substantially toroidal shape, defines an optical axis and a primary center of curvature disposed along the optical axis. The source of electromagnetic radiation is located approximately on the optical axis but axially offset a first distance from the center of curvature in a direction toward the concave surface portion. The target, such as a single core fiber optic or a fiber optic bundle, is located approximately on the optical axis but axially offset a second distance from the center of curvature in a direction away from the concave surface portion for acquiring a substantially focused image of the source reflected by the concave surface portion. With this configuration, the first and second distances are approximately related by the equation (1-z.sub.s /r1).times.(1-z.sub.i /r1)=1 where z.sub.s is the first distance, z.sub.i is the second distance and r1 is the primary radius of curvature of the toroidal reflecting surface portion of the primary reflector when a toroidal reflector is used for partial compensation of aberrations. In an alternate embodiment, a secondary reflector may further be added behind the source on the side opposite the primary reflector to enhance further light collection. According to a second alternate embodiment, the system may also comprise a housing having sides with inner surfaces forming the primary reflector and the secondary reflector.

Condensing and collecting optical system with axially displaced concave

The present invention provides a fiber optic coupling apparatus for coupling light from a high power light source into a fiber optic while preventing thermal damage to the fiber optic at the fiber-to-light source coupling. The light source comprises a housing having a fiber input structure with inner surfaces defining a through-hole for receiving the fiber optic. The fiber input structure has outer surfaces which define a substantially conical profile of the structure that extends within the housing such that an axis of symmetry of the fiber input structure is substantially coincident with the light input to the fiber optic. The fiber input structure is further made from a high heat conductivity material and has a reflective coating on an input end face for reflecting light that is outside the acceptance angle of the fiber optic, but incident upon the fiber input structure. An elongated, fiber support tube made from a high heat conductivity material is disposed around the fiber optic and extends freely within an internal cavity of the fiber input structure to isolate the fiber optic from the inner surfaces of the fiber input structure and to direct thermal energy away from the fiber-to-light source coupling.

Fiber optic, coupling apparatus having means for preventing thermal

The present invention provides a fiber optic connector having a shielding apparatus for protecting the exposed end of a fiber optic. The shielding apparatus of the connector generally comprises a cylindrical housing, a collet, and a protective sleeve. The cylindrical housing comprises first and second ends and a through-hole for reception of a fiber optic having a fiber optic end protruding from the first end of the cylindrical housing. The collet comprises a tubular body with first and second ends and a through-hole passing between the ends for movable reception of the cylindrical housing, with the second end of the tubular body being split to form a plurality of prongs arranged coaxially with the through-hole of the collet. The tubular body also comprises an inner surface with an inner flange disposed proximate to the second end of the collet for contacting the second end of the cylindrical housing and an outer surface with first and second opposing shoulders defining a recess in the outer surface of the collet. The protective sleeve comprises first and second ends, a through-hole passing between the ends for movable reception of the collet and an inner surface having an inner flange for disposition within the recess of the outer surface of the collet. With this arrangement, the shielding apparatus can be placed in an unprotected mode to expose the fiber optic end when the sleeve and cylindrical housing are moved towards the first and second ends of the collet, respectively, or it can be placed in a protected mode to shield the fiber optic end when the sleeve and cylindrical housing are moved towards the second and first ends of the collet, respectively.

Fiber optic connector having a shielding apparatus for protecting the

An off-axis optical system for collecting and condensing electromagnetic radiation utilizes an ellipsoidal reflector or a portion thereof configured so that the effects of magnification and optical aberrations (caused by the off-axis arrangement and an aspherical source envelope) are minimized. This is accomplished by the utilization of a specially designed ellipsoidal reflector having primary and secondary focal points along the major axis of the reflector or an effective reflecting portion thereof defined as that portion which is both illuminated by the source and subtended by the acceptance cone of the target. In the preferred embodiment, a single ellipsoidal reflector is configured with its major axis both non coincident with its geometric optical axis and with the optical axis of the target at an angle greater than zero degrees so as to reduce substantially the distance at which a focused image is formed and to achieve an average magnification near unity thereby maintaining the brightness of the source at the target. The radiant flux at the location of the target can be increased by incorporating a retro-reflector of toroidal or spherical design. In a second embodiment, the components forming the optical system of the present invention are arranged in a self-contained nautilus-shaped housing wherein the inner surface of the housing preferably comprises a reflector encompassing the retro-reflector, an effective ellipsoidal reflecting portion and a window through which the image is projected onto the target. In a third embodiment, the present invention utilizes a compound ellipsoidal reflector configuration having two ellipsoidal reflecting surfaces arranged so as to have a common focus, at which point a radiation source is located. In this embodiment, two targets located at the remaining foci of the respective reflectors are illuminated with a high flux density.

Condensing and collecting optical system using an ellipsoidal reflector

An angioplasty system and method for identification and laser ablation of atherosclerotic plaque at a target site in a blood vessel includes fluorescence analysis for identification of noncalcified plaque and calcium photoemission analysis for identification of calcified plaque. Calcified plaque is identified by time domain analysis of calcium photoemission. A high energy pulsed ultraviolet laser can be used for stimulation of fluorescence and for stimulation of calcium photoemission. The system is capable of distinguishing between calcium photoemission and a defective condition of optical fibers that are used to deliver laser energy to the target site. In an another embodiment of the angioplasty system, calcium photoemission is identified during a nonablative initial portion of the laser ablation pulse. When calcium photoemission is not identified, the laser ablation pulse is terminated during the initial nonablative portion thereof.

Angioplasty system having means for identification of atherosclerotic

A laser catheter includes an elongated tubular catheter body, one or more optical fibers extending through the catheter body and a catheter window mounted at the distal end of the catheter body. The optical fibers direct laser energy through the catheter window for removal of biological material. A diffraction grating is formed on the proximal surface of the catheter window in alignment with laser energy from the optical fibers. The laser energy is modified by the diffraction grating to provide a desired spatial distribution pattern. Preferably, the diffraction grating provides a diverging beam suitable for forming a hole in an obstruction, the hole having a diameter that is approximately the same as the diameter of the catheter. The diffraction grating enables formation at the distal end of the catheter of a beam pattern having an elliptical or other noncircular cross section. In another embodiment, an optical fiber with a noncircular cross section is used to shape the laser radiation emitted from the laser catheter.

Laser catheter having diffraction grating for beam shaping

A diffusion tip coupled to the end of an optical fiber for directing laser energy outwardly in a cylindrical or other desired radiation pattern. The diffusion tip includes a core, a cladding around the core and a jacket around the cladding. The cladding has an index of refraction that is lower than that of the core and has a thickness selected to transmit a portion of the laser radiation that is carried through the optical fiber so that laser radiation penetrates through the cladding and the jacket over the length of the diffusion tip. The thickness of the cladding is about the same as or slightly less than the penetration depth of the evanescent field in the cladding. The cladding can be tapered along the length of the diffusion tip to provide a uniform radiation pattern. The diffusion tip is particularly useful in a laser balloon catheter utilized in coronary angioplasty.

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Studio City, CA, United States of America

Glenn S Baker