Abstract: A solder joint or seal attaching components having dissimilar coefficients of thermal expansion is made thin (e.g., less than 20 ?m and preferably about 5 ?m) and of a solder such as an indium-based solder that has a tendency to creep. The solder is toroidal or otherwise shaped to avoid tensile stress in the solder. Axial shearing stress in the solder causes reversible creep without causing failure of the joint or seal. In one embodiment, a toroidal solder seal has a diameter, a footprint, and a thickness in approximate proportions of 5000:200:1.

Abstract: Multiple diffractive devices containing an environmentally delicate material such as photoresist are fabricated on a single substrate that is later cut to separate devices. One process shapes the material into multiple contoured regions on a single substrate. Each contoured region has the topography needed for a diffractive device and is separated from other contoured regions by saw streets. A seal layer, which may include an adhesion layer and a reflective layer is deposited over the contoured regions and extends into the saw streets. Cutting the substrate separates the diffractive devices with each diffractive device hermetically sealed between the seal layer and the substrate.

Abstract: Fluxless soldering processes use pressure variations and vented cavities within large-area solder joints to reduce void volumes and improve the properties of the large-area solder joints. The vents can be sealed after soldering if closed cavities are desired. A cavity can also improve hermeticity of a solder joint by providing an additional solder fillet around the cavity in addition to the solder fillet around the perimeter of the solder joint.

Abstract: An assembly and an optical element have fiducials for alignment of multiple beam paths during fabrication of an optical device. In an assembly including a substrate with machined grooves for optical fibers, a fiducial can be a carbon-coated fiber or other object disposed in one of the grooves. In an assembly including a collimator array, a fiducial can be an opaque collimator lens. Alternatively, photolithographic processes can provide the required positional accuracy for fiducials on the assembly and/or the optical element. During alignment, a computer-controllable process can use machine vision or distance measurements to identify the position and the orientation of the assembly relative to the optical element. Based on the identified position and orientation, the process moves the assembly to the target position and orientation that provide sufficient optical power flow through the optical element for a fine alignment process.

Abstract: A solder joint or seal attaching components having dissimilar coefficients of thermal expansion is made thin (e.g., less than 20 &mgr;m and preferably about 5 &mgr;m) and of a solder such as an indium-based solder that has a tendency to creep. The solder is toroidal or otherwise shaped to avoid tensile stress in the solder. Axial shearing stress in the solder causes reversible creep without causing failure of the joint or seal. In one embodiment, a toroidal solder seal has a diameter, a footprint, and a thickness in approximate proportions of 5000:200:1.

Abstract: Fluxless soldering processes use pressure variations and vented cavities within large-area solder joints to reduce void volumes and improve the properties of the large-area solder joints. The vents can be sealed after soldering if closed cavities are desired. A cavity can also improve hermeticity of a solder joint by providing an additional solder fillet around the cavity in addition to the solder fillet around the perimeter of the solder joint.

Abstract: An assembly and an optical element have fiducials for alignment of multiple beam paths during fabrication of an optical device. In an assembly including a substrate with machined grooves for optical fibers, a fiducial can be a carbon-coated fiber or other object disposed in one of the grooves. In an assembly including a collimator array, a fiducial can be an opaque collimator lens. Alternatively, photolithographic processes can provide the required positional accuracy for fiducials on the assembly and/or the optical element. During alignment, a computer-controllable process can use machine vision or distance measurements to identify the position and the orientation of the assembly relative to the optical element. Based on the identified position and orientation, the process moves the assembly to the target position and orientation that provide sufficient optical power flow through the optical element for a fine alignment process.

Abstract: This disclosure provides an image screen having anti-reflective qualities, such as might be used in projection television. In particular, an opaque black layer is formed on a front, viewer-side of the screen using the transmissive properties of the projection screen itself, e.g., as defined by a bubble lens array on the back side of the screen. In one embodiment, light is transmitted through a Fresnel lens, through a bubble lens array, and onto a photoresist to expose transmissive “pinholes” in the photoresist. Photoresist is then removed in unexposed areas, and an anti-reflective material is deposited over the entire viewer-side of the screen. Remaining photoresist is then removed from transmissive areas to leave the anti-reflective material in all areas not receptive to projection light. The material is developed and cured and the front side is optionally protected with a sealant layer.

Abstract: A device for storing and deploying cable, including but not limited to optical fiber cable. The device includes a substantially planar bottom support surface having juxtaposed thumb segments and an intervening finger segment. An outer wall is affixed to the bottom surface about its perimeter and extends upwardly therefrom. A substantially circular guide wall is disposed on the bottom surface extending upwardly therefrom. A substantially circular inner wall is concentrically arranged with respect to the guide wall. A top flange is joined to the support surface by the outer wall and, together with the thumb segments, form entry and exit ports for the cable. The guide wall and the inner wall define a guide track that is dimensioned so as to enable continuous adjustment of variable lengths of cable in an area of the device bounded by the guide track, the outer wall and a transverse barrier that extends the length of the finger segment.

Abstract: The invention provides an improved donor substrate for the formation and transfer of solder bumps useful in IC packaging and related interconnect applications. The donor substrate is improved by shaping the solder paste containment region (cavity) so that during reflow, the solder bump is urged to protrude significantly above the surface of the donor substrate, enabling proximity transfer of the solder bump to a receiving substrate.

Abstract: A micro-photonics device is described that includes a substrate and a plurality of optical and electrical components mounted on the substrate. The optical and electrical components form a transmitter and a receiver. A wall is mounted on the substrate to physically separate some of the components from other components to prevent electrical and optical interference between the transmitter and receiver. The wall mounted on the substrate may also be mounted with electrical and optical components of the micro-photonics device. In this case, the wall physically separates the components mounted on the substrate from the components mounted on the wall to prevent electrical and optical interference. Moreover, the wall with the mounted components may simply be attached to a side surface of the substrate.

Abstract: An micro-photonics module includes an optical component and a photonics device mounted on a single substrate. The substrate defines a rectilinear cavity with flat bottom and flat side. The photonics device mounted on the substrate at a predefined distance from the cavity defines an optical path aligned to cross the rectilinear cavity. The optical component with portion abutting the flat bottom, flat side, and locator surface, is aligned with the optical path by the flat bottom and flat side of rectilinear cavity. The substrate may also define pyramidal cavity formed into the substrate from a major surface of the substrate, a notch formed in the substrate from the major surface and the flat side of the rectilinear cavity, and a locator surface within the rectilinear cavity. A ball lens may be seated in contact with the substrate within the pyramidal cavity to have a predefined relationship with the photonics device. The notch allows light to pass unobstructed between the ball lens and the optical component.

Abstract: A method of precisely mounting a planar optical component on a mounting member includes the step of placing a plurality of balls on the mounting member to precisely define a geometric plane. The planar optical component is then placed against each of the balls on the mounting member such that the planar optical component is along the defined geometric plane on the mounting member. In addition, the planar optical component can also be mounted on the mounting member by first forming a groove in the mounting member. An end of the planar optical component is then shaped to match that of at least one wall of the groove. The planar optical component can then be placed in the groove such that the shaped end of the planar optical component is placed against the wall of the groove.

Abstract: An optical submount and a method of making the optical submount are described. A cavity is formed in a substrate. The cavity has sloping side walls. A photonics device is then mounted on the substrate at a predefined distance from the cavity with the optical axis of the photonics device aligned with a diagonal of the cavity. A spherical lens is seated in contact with the side walls of the cavity to have a predefined relationship with the photonics device without light beam obstruction.

Abstract: A switch for selectively coupling light from an input optical fiber to a selected one of a plurality of output optical fibers. The switch includes a first carriage having one end of the input optical fiber attached thereto and a second carriage having the output optical fibers attached thereto such that one end of each of the output optical fiber lies between first and second distances with respect to the end of the input optical fiber when the output optical fiber is aligned with the input optical fiber. A lens that is fixed with respect to the end of the input optical fiber images light leaving the input optical fiber onto a plane lying between the first and second distances from the end of the input optical fiber. In one embodiment of the present invention, an encoder is integrated into the first and second carriages. The encoder includes an encoding input optical fiber having one end attached to the first carriage, the encoding input optical fiber being a single mode optical fiber.

Abstract: A selective contact to a NIPI doping superlattice having a trap free (or low trap density) contact in contact with the layers of the superlattice. In a NIPI superlattice, the trap free region is a doped region that can be produced: by diffusion of dopant ions from a doped metal contact; by overdoping of the edges of the superlattice; or by overgrowth of the edges of the superlattice with a doped material that is trap free.