At&t Bell Laboratories

Other

At+t Corp.

American Telephone and Telegraph, Co.

Richard J Coyle, Jr

Gary J Grimes

Anthony J Serafino

George J Shevchuk

Lawrence J Haas

Lee L Blyler

Kevin Matthew Hogan

Paul J Sakach

Jaroslav Mracek

Patrick P Solan

Replacing costly electro-optic or fused quartz crystalline structures or molded plastic optical waveguide splitters with an optical switch comprising an array of spatial light modulators between two relatively, thick, optical glass flats. Associated with each spatial light modulator are partial holes in the optical glass flats with the partial holes being in alignment with the spatial light modulator. Using a new experimentally-developed laser technique, these holes can be drilled to a precise depth so that the distance between the ends of standard silica optical fibers inserted into opposing holes approximates the diameter of those fibers. Since the diameter of a partial hole is insignificant compared to the overall area of an optical glass flat, the physical strength of the optical glass flats is not reduced even when a number of partial holes are drilled into the optical glass flats. In addition, since thick optical glass flats are used, the contrast ratio and switching speed of such an optical switch is not impaired.

Optical switch having spatial light modulators

Welding a first body (11) of a first metal which has been plated on one surface thereof with a layer (13) of a second metal comprises the step of vaporizing a portion of said layer. This is done by directing a first pulsed laser beam (17) at the layer (13), the first pulsed laser beam having a first relatively high peak power and a first relatively low pulse duration. The vaporizing results in exposure of a portion of the first body (11). Thereafter, part of the first body is melted by directing a second pulsed laser beam (20) at the exposed portion of the first body, said second pulsed laser beam having a second peak power smaller than the first peak power and a second pulse duration longer than said first pulse duration. By using the same laser (18) in a two-step process, first to vaporize a portion of the plating, such as gold plating on Kovar, and thereafter using the same laser for making the weld, one can avoid a microcracking problem in a manner that is quick, simple and convenient.

Laser welding methods

A method for fabricating a high efficiency optical coupler by matching the emerging light exit pupil from a coupler opening to the acceptance shape of a couple optical fiber. An excimer laser forms the coupler opening in an optical fiber by removing cladding from the optical core surface. The coupler opening has an elliptical shape resulting in an emerging light exit cone, and that exit cone matches an acceptance cone of a circular coupler optical fiber.

Apparatus for fabrication of optical couplers

A method for fabricating optical components in the cladding of an optical fiber bus by the utilization of a laser. An excimer laser fabricates either an optical coupler opening or an optical mode scrambler by ablatively removing the cladding from the optical core of an optical fiber bus without damaging the optical core. Either coupler housing or a mode scrambler housing is attached to the optical fiber bus where the coupler or mode scrambler is to be fabricated. The coupler housing is used to position the laser, secure and align a coupler fiber, and provide cavities for junction and cladding repair materials. The mode scrambler housing serves a similar purpose.

Fabrication of optical components utilizing a laser

A cladding portion (15) of an optical fiber (16) is laser machined by focusing a laser beam (13) that is of an appropriate wavelength to ablate the cladding. When the laser beam completely penetrates through the cladding (15) to impinge on the optical fiber core (18) light is transmitted to the two ends of the fiber. A photodetector (31) is placed in close proximity to one of the ends of the optical fiber (16) with the photodetector output being connected to a laser control device (23). When the light detected by the detector exceeds a threshold, it generates a signal that stops the laser. Even if the cladding is of an unpredicted thickness, the laser beam is not terminated until there has been complete penetration through the cladding, and after complete ablation the laser beam is promptly terminated so as to avoid subsequent damage to the optical fiber.

Methods and apparatus for making optical fiber couplers

A method for fabricating a high efficiency optical coupler by matching the emerging light exit pupil from a coupler opening to the acceptance shape of a coupler optical fiber. An excimer laser forms the coupler opening in an optical fiber by removing cladding from the optical core surface. The coupler opening has an elliptical shape resulting in an emerging light exit cone and that exit cone matches an acceptance cone of a circular coupler optical fiber.

Fabrication of optical couplers

An apparatus for fabricating optical fiber mode scramblers and optical fiber couplers as an integral part of an optical bus by the utilization of a laser to remove cladding on the optical fiber bus to form the mode scramblers and couplers. An excimer laser is utilized to ablatively remove the cladding which is a polymer material. The optical core is composed of a material which is not readily affected by the excimer laser. The optical bus is fabricated by enclosing an optical fiber in an optical bus assembly. The optical fiber has only cladding and an optical core and has no buffer surrounding the cladding. The optical bus assembly provides for a plurality of optical couplers for removing and adding light to the optical bus and intermixed with the optical coupler are a plurality of optical scramblers.

Fabrication of an integrated optical fiber bus

An excimer laser fabricates either an optical coupler opening or an optical mode scrambler by ablatively removing the cladding from the optical core of an optical fiber bus without damaging the optical core. Either coupler housing or a mode scrambler housing is attached to the optical fiber bus where the coupler or mode scrambler is to be fabricated. The coupler housing is used to position the laser, secure and align a coupler fiber, and provide cavities for junction and cladding repair materials. The mode scrambler housing serves a similar purpose.

Laser welding of an outer sleeve 14 to an inner fiber ferrule 12 is expedited by, first, machining a thinned region 18 in the outer diameter of the sleeve. After the ferrule has been inserted in the sleeve, the thinned region permits the laser to fuse through the sleeve and melt part of the ferrule, as is required for laser welding of ferrule for the sleeve. The thinned region is preferably made by using a rotary cutter to cut an axially extending slot in the outer sleeve, which permits a succession of laser welds 21 in the axial direction in the slot. In a preferred embodiment, thinned regions 18,19 are made on opposite sides of the outer sleeve, and laser welding is performed simultaneously on both sides of the sleeve so as to avoid distortions caused by thermal stress asymmetries.

Growing community of inventors

Lawrenceville, NJ, United States of America

Richard J Coyle, Jr