Abstract: A method of decapsulating a packaged die includes removing packaging material from the bottom section of a die-containing package to expose a die pan, removing the die pan, removing material between the die pan and the bottom surface of the die, using the bottom surface of the die to determine a grind plane substantially parallel to the top surface of the die, and removing packaging material from the top section of the die-containing package to form a top surface substantially planar to the grind plane, preferably intersecting the wire bonds on the face of the die.

Abstract: A method of forming an optical channel waveguide by gettering includes forming on a substrate a porous waveguide layer containing an index of refraction raising dopant in a compound; sealing a portion of the waveguide layer along a path; and reacting the component, including the index of refraction raising dopant, with a reactant in the unsealed portion of the waveguide layer to form a volatile product from the reactant and dopant to deplete the dopant in the unsealed portion of the waveguide layer and reduce its index of refraction relative to that in the path to produce a channel waveguide along the path.

Abstract: A method of forming an optical channel waveguide includes forming on a substrate a waveguide layer of silica doped with an index of refraction raising dopant whose concentration profile in a first dimension includes a higher concentration region and an adjacent lower concentration region; and heating the waveguide layer along two spaced areas defined in the second and third dimension which define a path between them for diffusing the dopant along the first dimension from the higher concentration region to the lower concentration region to reduce the index of refraction of the higher concentration region in portions of the higher concentration region proximate the spaced areas and create a waveguide along the path.

Abstract: A method of forming an optical waveguide which includes the steps of forming on a substrate a waveguide layer including at least one host medium and one dopant medium, one of which is more volatile than the other; and heating the waveguide layer to selectively volatize the more volatile medium along a path, raising the index of refraction and creating a waveguide along the path.

Abstract: A fiber optic laser includes a fiber optic element, and a Bragg grating means in the fiber optic element and defined by a periodic variation in the index of refraction of the element to enhance the narrow band response of the laser and/or increase the loss of unwanted frequencies. A method of making the fiber laser is also disclosed.

Abstract: A method of fabricating rare earth doped planar optical waveguides for integrated optical circuits includes introducing a first carrier gas to a heated column of rare earth chelate to create a flow of rare earth chelate vapor in the carrier; introducing a second carrier gas through a silicon precursor to create a flow of silicon precursor vapor in the carrier; submitting the flow of rare earth chelate vapor and the flow of silicon precursor vapor with oxygen and a homogenizing agent to a flame hydrolysis deposition burner to produce a soot of rare earth doped silica; and depositing the soot on a planar substrate; and etching the soot, after consolidation, to define one or more discrete channel waveguides.

Abstract: An optical fiber includes a multimode primary core having an index or refraction N.sub.1 and doped with a material providing optical gain; the cladding surrounding the core having an index of refraction N.sub.2 ; and a secondary core doped with an absorbent material for providing optical loss in unwanted modes.

Abstract: A method for fabricating optical fibers having a rare-earth doped core and a fused silica cladding includes inserting a rare-earth doped soft glass rod into a fused silica tube, the ratio of the outer diameter (OD) to the inner diameter (ID) of the fused silica tube being at least 2 and as large as 50; heating the rod and tube combination in a furnace to selectively volatilize volatile constituents of the soft glass rod which are responsible for the low softening point so that the final composition of the core consists predominantly of SiO.sub.2 and the desired dopants such as rare earths, alkaline earths or other low vapor pressure materials; and drawing the perform into an optical fiber.

Abstract: A chemical vapor deposition method which utilizes a rare earth chelate vapor as a source of rare earth ions for producing an optical fiber having a core with a high rare earth content.

Abstract: Apparatus for coupling radiation into a single-mode core of an optical fiber laser has a single-mode core disposed within a relatively large, multimode cladding at a location which is displaced from the center of the cross-section of the cladding. The cladding is surrounded by a further layer to prevent radiation from propagating out of the cladding. In addition, the apparatus preferably has slight bends to enhance the coupling of radiation from the cladding into the single-mode core. A further embodiment has a single-mode fiber laser disposed in a relatively large, multimode, slab cladding which, in turn, is surrounded by another cladding to prevent radiation from propagating out of the large cladding.