Abstract: The present invention provides a method of annealing optical glass layers, said method comprising the step of heating glass layers having an area greater than 0.01 cm.sup.2 to a temperature of between about 350 deg. C. and 1000 deg. C. in less than 10 minutes. The upper limit of the glass area that can be treated is limited only by the size of the quartz chamber. Current state-of-the-art chambers can accomodate glass areas of about 0.01 cm.sup.2 to about 324 cm.sup.2. According to another aspect of the invention, there is also provided an optical waveguide glass layer, treated according to the method of this invention, disposed on an integrated optical device.

Abstract: Fiber optic couplers formed of at least two single mode optical fibers, at least one of which is an input fiber, are shown, the fibers constructed and arranged in the manner that coupling between the input fiber and the other fibers limits antisymmetric modal energy to substantially less than 50% of the input energy, the coupling region of said coupler being fused and drawn to an extended length sufficient to cause cutoff of the antisymmetric mode energy, whereby the coupler exhibits coupling ratio stability over an extended range of wavelengths and an excess loss of substantially less than 50%. Numerous fiber couplers of various construction, all employing cut-off of the antisymmetric mode to achieve wideband response or wavelength insensitivity are shown along with their method of manufacture.

Abstract: A CRT bulb that has been preloaded to counter the atmospheric load placed on the seal area of an evacuated and sealed CRT is disclosed along with methods of constructing the bulb. The front panel is simply supported on the funnel and deflected inwardly during affixation of the panel to the funnel to form the bulb. When the deflection load is removed from the affixed panel, the resultant strain energy imparted to the bulb seal area offsets at least some of the atmosphericly induced strain on the sealed CRT. The bulb has a more evenly balanced stress distribution between the front panel and the funnel seal area than previous flat panel CRTs, enabling the use of thinner front panels and seal land.

Abstract: An optical two-way transmission-received communications system utilizing a coaxial coupler in place of a standard coupler, the optical system being capable of operation either in a single or multiple wavelength mode by designing the coupling region to have the proper length (i.e., either in 3dB or WDM operation), and further comprising a transmitter and a detector adjacent a coaxial coupler. The detector of the system is provided with a hole in its center in order to allow the transmitter access to the core waveguide of the coaxial coupler. The coaxial coupler may be formed from a rod in tube structure with a core waveguide extension adjacent the Tx/Rx and an integral pigtail on the opposite side of the coupler.

Abstract: According to the bonding method of flat electrodes of the present invention, a crystal glass material is arranged between electrodes, heated, and melted while the flat electrodes are pressured, and the melted crystal glass material is fused and re-crystallized to the surface of each flat electrode, so that the flat electrodes can be bonded with strong bonding force. Since a plate-like spacer or an application glass of a low melting point is not used in the method, disadvantages resulting from the spacer or the glass can be removed.

Abstract: In a method of preventing twisting of a fusion-spliced optical fiber in the process of encasing the optical fiber in a casing, one of a pair of optical fibers is wound N turns in one direction to form a first coil. Another of the pair of optical fibers is wound N turns in another direction opposite to the direction to form a second coil. Ends of remainder portions of the optical fibers which are not wound are fusion-spliced to each other to form a fusion-spliced portion. The fusion-spliced portion is fixed within a casing. The remainder portions of the optical fibers are pushed into the casing to expand the first and second coils.

Abstract: A method for fabricating defect-free optical fiber preforms without light scattering defects such as core-clad interface bubbles, core-clad crystalline inclusions and core glass crystals involves first forming a cladding glass shell preferably by rotational casting, then separately melting core glass inside a cylindrical crucible and quenching using metallic quenching blocks to prevent crystal formation in the core glass, next heating the core containing crucible to the core glass softening point and also heating the cladding tube containing mold to the glass transition temperature of the cladding glass, then placing the cladding tube containing mold inside the core glass crucible and pushing it downwardly with high pressure so that the softened core glass is forced into the cladding glass tube, and finally the preform is annealed to remove thermal stress. Subsequently, the preform is drawn into optical fibers using conventional technology.

Abstract: An apparatus for use in the manufacture of a color cathode ray tube that includes a faceplate with a screen embraced by which rails support a flat tension mask. The apparatus includes a radiant heat source for heating the faceplate, and shielding means including a heat shield for shielding a central area of the faceplate from the radient heat source. Stresses induced in the corners of the faceplate by the rails during thermal cycling of the tube are dispersed in the cooler central area of the faceplate.

Abstract: An optical fiber fusion splicer includes a discharge unit for producing an electric discharge to fusion splice optical fibers and a pressure sensor for producing a pressure detection signal representing the surrounding atmospheric pressure. In response to the pressure detection signal the discharge is controlled by a control unit so that a substantially optimum discharge current for the fusion splicing is provided to the discharge unit. The discharge control unit includes an adjusting unit for producing a discharge current adjusting signal, a control signal generating unit for generating a control signal on the basis of both the pressure detection signal and the discharge current adjusting signal, and a discharge current control unit for controlling the discharge current in response to the control signal.

Abstract: Signal strength in an optical fiber transmission path is attenuated in one direction to a desired lower level by incorporating a selected length of coreless, undoped fiber of the same diameter into the signal-carrying fiber. On encountering the insert, the beam diameter expands to a pre-selected value at the far end of the insert. The ratio of the beam diameter at this point to the diameter of the adjacent fiber end establishes the attenuation factor. Steps are taught for achieving high consistency in both structural strength of the attenuator as well as the attenuation factor.

Abstract: A low magnetic isolation closure glass for use in multitrack magnetic tape heads has been prepared by combining a specific lead borosilicate glass with a specific borosilicate glass in a 60/40 weight percent ratio. The glass formed from the combination exhibits compatibility with ferrite and has reduced wear. Controlling the anneal temperature regulates the residual stress of the closure glass produced, and thus, provides some control over the wear characteristics of the glass.

Abstract: A fiber optic coupler has at least two optical fibers each having a core with a cladding material disposed thereabout. The fibers, in a limited length coupling region, have the cladding material removed and the core exposed, the thickness of the cladding material increasing is smooth transition from immediately adjacent the exposed core in the limited length coupling region. The fibers in the limited length coupling region are joined by coalescing. In preferred embodiments, in the limited length coupling region, a portion of the core is removed, the core diameter in the coupling region being less than the core diameter in regions adjacent thereto, the outer diameter of the core decreasing in smooth transition from immediately adjacent the cladding material. A method and product of forming these couplers or others with the fibers in crossed relationship are also described.

Abstract: In a method for the production of cylindrically symmetric bodies with given radial gradient of the material properties, for example of the refractive index, at least two rod-shaped molded bodies consisting of materials with different properties are joined in parallel and, following lowering of the viscosity of both materials, the bodies are twisted many times in a spiral around a longitudinal axis, such that a desired radial gradient of the material properties arises, where metallic, semiconducting, or insulating materials may be used, and the viscosity is varied through changing the temperature or adding or removing a solvent.

Abstract: A damage detection and evaluation system utilizes optical fibers to detect and assess damage to a structure. The optical fibers are intermittently etched in a controlled manner to weaken them so they fracture when a desired load is applied to the structure. Where visual inspection of the optical fibers is used to check for damage, a reference set of optical fibers is used. Where photodetection is used and minimal connections to the structure are required, one end of the optical fiber is made reflecting so an optical connection is only made to the other end. To further simplify the connection, a single input/output optical connection to a demultiplexing/multiplexing chip mounted on or within the structure is provided. Where orthogonal grids of fibers are not possible, the invention provides interdigitated optical fibers and volume backscattering to locate the position of the first fracture along the length of the optical fiber.

Abstract: A multidirectionally fiber reinforced-glass matrix composite article is disclosed. The fiber reinforcement is precisely oriented in three or more directions to provide high strength and stiffness in each of the three or more directions. A method for making a multidimensionally fiber reinforced glass matrix composite article is also disclosed. The method includes impregnating a fiber preform with a colloidal suspension of inorganic material, cooling the impregnated fiber preform to precipitate the inorganic material, drying the preform, impregnating the preform with heated glass matrix material, and cooling the glass impregnated preform to form the multidirectionally fiber reinforced glass matrix composite article.

Abstract: A method of forming a single mode biconical fiber optic coupler comprising holding 2 or more optical fibers parallel to and in contact with each other at spaced apart locations, exerting equal tension in opposite directions to the fibers at said spaced apart locations to stretch the fibers, fusing the fibers over a waist region, and scanning the tip of a flame from a microtorch back and forth along the fibers at a speed which is at least five times the speed of stretching of the fibers. This results in an overcoupled low loss coupler, a pressure or a temperature sensor, comprised of at least a pair of monomode optical fibers fused and parallel at a stretched waist portion, each having biconical tapers at opposite ends of the waist portion, the coupler having exhibited at least about 500 power transfer cycles during stretching formation of the waist portion.

Abstract: A method for producing reflectors in a continuous length of optical fiber is disclosed. The present process includes the steps of preparing the ends of two or more optical fibers, placing one or more of these fibers in a vacuum system and applying a metallic or dielectric coating to the fiber ends, and then fusing the prepared, coated ends of the fibers together until the reflectivity of the region reaches a desired value.

Abstract: Gradient optical density transmissive light directing devices (24, 26, 28, 30) and fabrication thereof are disclosed herein. Examples of such devices include concentrators, lenses and compound lenses. The present invention teaches a process for the fabrication of glass light transmitting devices having a chosen gradient in index of refraction either bidirectionally (radially and longitudinally relative to an optical axis) or in three dimensions. The present invention further describes the design of several interesting optical devices by particular choices of the gradient in the index of refraction thereof. Such articles have numerous uses in the optics, optical fiber and solar technology industries for the purposes of designing compound lens systems using a single, integral lens, coupling light into fibers and for concentrating and directing light from a source having a significant angular variation to an energy collecting and/or conversion devices such as a photovoltaic cell, to name but a few applications.

Abstract: An attenuating device 10 for use with signal carrying optical fibres 14 comprises a length 18 of optical fibre coiled within a casing 16. The optical fibre length 18 is of higher attenuation per unit length than the optical fibres 14 and the device comprises means, for example optical fibre tails 22,24 fusion spliced at 20,22 to the opposite ends of the length 18 for optically connecting those ends to the fibres 14.

Abstract: A microchannel electron multiplier is formed by placing into a glass tube a plurality of bundles optical fibers, each having an etchable glass core and a glass cladding which is non-etchable when subjected to the conditions used for etching the core material. The fiber bundles located around the inside edge of the glass tube are replaced by support fibers having both a core and a cladding of a material which is non-etchable under the above-described conditions. The assembly of the tube, bundles and support fibers is heated to fuse the tube, bundles and support fibers together. The etchable core material is then removed and the assembly sliced into wafers. The inner surface of each of the claddings which bound the channel formed after removal of the core material is rendered electron emissive by reduction of the lead oxide by hydrogen gas. Metal films are deposited onto the opposed surfaces of each of the wafers to form contacts.

Abstract: New fiber optic elements and a new microchannel plate for proximity focus image intensifier tubes and a method for making them are provided. Higher resolution is provided at the center of the field of view by the use of graded fiber and channel sizes and by the use of convex and concave surfaces in proximity focus.

Abstract: Method for bonding the edges of all-glass multiple panes, particularly all-glass double panes, whereby the individual panes moving through an elongated tunnel furnace or the like are cut to size, may potentially be washed, are subjected to an at least partial edge smoothing, are aligned with one another and, after being pre-heated to a pre-heating temperature lying below the deformation temperature of the glass, are bonded to one another at the horizontal and vertical pane edges, being bonded while standing upright, characterized in that individual panes cut to size and potentially washed are individually pre-heated lying on their surface facing away from the pane interspace of the all-glass multiple pane to be manufactured, and in that the individual panes are subsequently placed upright and are placed together to form groups of individual panes in accord with an all-glass multiple pane to be manufactured, whereupon the edge bonding ensues; further, apparatus for the implementation thereof.

Abstract: A method of forming a fiber-reinforced, glass or glass-ceramic, elongated composite is described wherein several multifiber lengths are impregnated with matrix material, woven or twisted to form a fabric network, the impregnating matrix material softened, and the network subjected to a stretching action along the central axis of the fiber network to collapse the network and consolidate it to a solid composite.

Abstract: A method of polishing a roof-shaped, or bevelled, tip having a predetermined angle on the end of an optical fiber is disclosed. The method comprises placing an optical fiber in contact with an abrasive tape at an angle corresponding to the desired predetermined angle. The fiber is moved towards the tape beyond the point of contact so as to cause a bend in the fiber. Upon moving the abrasive tape, the compliance of the fiber, by virtue of the bend, provides a pressure of the fiber against the tape to enable polishing to occur. As polishing continues the pressure decreases until enough material is removed so as to eliminate the bend and impart the predetermined angle to the fiber tip. The fiber may be rotated to polish the other side in a similar manner, if so desired.

Abstract: Polarization beam splitters/combiners or polarization insensitive beam splitters/combiners are manufactured from low or zero birefringence single mode optical fibre, rather than high birefringence fibre, by using a differential pulling technique to induce the appropriate amount of form birefringence, the fibres being stretched further than hitherto.

Abstract: A method is provided of manufacturing a device for conducting quantized particles such as photons and electrons. The method comprises the following steps:providing a layer of magnetizable material throughout the length of a conductor;dividing the conductor into conductor pieces having a predetermined length;aligning the conductor pieces by means of a magnetic field in such a manner that their ends are positioned perpendicularly to an abutment face;bundling the conductor pieces to a dense packing; andjoining the bundled conductor pieces to a mechanical unit.The method is preferably carried out in such a manner that the abutment face extends substantially perpendicularly to the direction of the gravitational field and that the attraction caused by the magnetic field is greater than and opposed to the force of gravity caused by the gravitational field.

Abstract: An optical fiber contact for terminating an optical fiber includes a memory tube material having a first section which has been recovered around a pigtail optical fiber. A second section of the memory material is nonrecovered, and an optical fiber is terminated by inserting a cleaved or polished end of the optical fiber into the nonrecovered tube section and recovering this tube section around the cleaved or polished optical fiber end. A plurality of contacts are disposed in first and second linear arrays which are then optically interconnected with an optical fiber contact assembly.

Abstract: In the interest of producing high-strength splice connections between silica-based glass fibers a method of using a tri-particle flow of gases for flame fusion is disclosed. An outer relatively high-velocity flow of oxygen surrounds an intermediate, lower-velocity flow of chlorine or oxygen which in turn surrounds a central flow of H.sub.2, D.sub.2, NH.sub.3, or ND.sub.3.Particularly high strengths are achieved when a central flow of hydrogen or deuterium and an intermediate flow of chlorine are used in such a fashion as to heat fiber ends to be spliced to temperatures of 500 degrees C. and beyond only after these ends have been enveloped by chlorine.

Abstract: A bundle of optical fibers each covered by an acid-soluble borosilicate glass is treated with an acid solution, with an alkali solution, and then with an acid solution to completely remove the acid-soluble glass from the middle portion between the end portions of the optical fiber bundle. A plastic material is charged into the interstices among the fibers at the boundary portions between the middle portion and the end portions. These interstices are free of any insoluble residue of the acid-soluble glass. A reinforcement is formed around the periphery of at least a part of the boundary portions by covering the periphery with a flexible plastic material or by winding a linear member around the periphery.

Abstract: A low loss fiber optic coupler is fabricated by forming a coupler preform having a plurality of spaced glass cores extending longitudinally through a matrix of glass having a refractive index lower than that of the cores. The coupler preform is heated and stretched by first pulling means to form a glass rod which is drawn by second pulling means past an intermittant source of localized heat. When the localized heat source is turned on, the second pulling means draws the rod downwardly at a rate faster than the first pulling means. Since the rod is softened by the localized heat source, a necked-down coupling region is formed. The rod is severed to form a plurality of coupler units. When an end of a unit is immersed in acid, the matrix glass dissolves, thereby leaving the unit cores and surrounding etch-resistant cladding glass protruding from the newly formed endface of the unit.

Abstract: An optical fiber comprising a core and cladding having different refractive indices and forming a single-mode guiding region, the core having a non-circular cross-section defining two transverse orthogonal axes which, in combination with the different refractive indices, permit the de-coupling of waves polarized along the axes. The guiding region is located sufficiently close to the surface of the fiber along a selected length of the fiber, to allow coupling to a guided wave. The outer surface of the fiber has a non-circular cross-section with a predetermined geometric relationship to the guiding region and the orthogonal transverse axes so that the location of the guiding region and the orientation of the axes can be ascertained from the geometry of the outer surface.

Abstract: The present invention relates to a fused-fiber optical coupler, and method of forming the same, which does not require a tapering of the fibers. A two-step fusion process is utilized where initially the end sections of the plurality (N) of output fibers are fused together to create a bullet-shaped end section. The bullet-shaped end section is then butt-coupled and fused to the input fiber (or M input fibers) to form a 1.times.N (or M.times.N) fiber coupler.

Abstract: A method for making a fluid lamp assembly which includes a fiberglass wick, consisting of approximately 100 individual fibers in a bundle, is inserted in a glass tube, adjusted with its tip a desired distance above opening, and fused in place by heating to 600 degrees Centigrade for 20 minutes. Fusing temperatures of from about 500 to 600 degrees Centigrade may be employed, for times of from about 10 minutes to about one hour, with a longer fusing time employed with lower temperatures. This provides a premanent wick that is not consumed in use of the lamp assembly.

Abstract: A method for fabricating an optical attenuator includes the following steps. Measuring the magnitude of optical loss imposed on an optical signal transmitted through first and second abutted optical fibers. Aligning the abutted ends of the first and second optical fibers for minimum distributed optical signal loss through both optical fibers, as measured at the far end of the second optical fiber. Heating the abutted ends of the first and second optical fibers into a plastic state. Physically distorting the optical fiber ends until the measured optical signal loss increases by a desired additional lumped optical loss value. Cooling the abutted ends of the first and second optical fibers to form a fusion splice imposing the desired additional lumped optical loss value between the ends of the first and second optical fibers.

Abstract: A non-linear waveguide component is formed by a pair of optical fibers disposed in side-by-side relation and defining between them a space of elliptical cross-section. A single crystal of electro-optic material is grown in situ in the space between the fibers and has major and minor crystal axes coinciding with the major and minor axes of the space.

Abstract: An advantageous method for fabricating an optical attenuator between the ends of two optical fibers uses the following steps. The axes of the cores of optical fiber ends are misaligned by an offset distance and then one of them is moved along its center axis until the ends of the fibers abut one another. Abutted ends of the optical fibers are melted. While the fiber ends are molten, surface tension aligns the axes of the cores of the optical fibers. Finally the abutted ends region of the optical fibers is cooled into a lumped optical attenuator.

Abstract: First and second spaced members are hermetically sealed by a partially amorphous and partially crystalline insulating material. The insulating material is non-hygroscopic and is able to withstand forces of about 26,000 psi at about 700.degree. F. It may provide resistances of at least 10,000 megohms even when subjected to 500 volts AC or DC and to steam at about 212.degree. F. for three (3) days. A second insulating layer may be fused to the first insulating layer with essentially the same properties and composition as the first layer. However, the second layer may be more crystalline than the first layer to provide a mechanical and chemical barrier. The insulating materials may be formed from the oxides of lead, zinc, aluminum, silicon, cerium, lanthanum, cobalt, sodium, zirconium, bismuth and molybdenum. The oxides of lead, silicon, bismuth and sodium may be glass formers. The oxides of cerium, lanthanum and zirconium may form crystals. A mixture of the oxides may be heated to at least 2000.degree. F.

Abstract: The invention comprises a method for coupling an optical fiber to an optical device. Ends of optical fibers are ion polished. Micro-manipulators are used to position the polished end in abutting relationship with the optical device. A liquid which contains glass constituents is used to coat the junction of the optical fiber and the optical device. The liquid is subjected to a temperature cycle which fuses the glass constituents to the optical fiber and to the optical device.

Abstract: In the thermal cycles utilized for frit sealing glass members together for forming a glass housing and for baking-out such housing, shielding means are provided to protect and shield those portions of the glass members having multiple surfaces which would otherwise be exposed to excess thermal energy, from such thermal energy so as to inhibit the formation of detrimental thermal gradients within the housing structure.

Abstract: A method of producing multifocal lens blanks by fusing a molten glass segment into a pressed countersink of a lens blank when it is being formed in which the pressed countersink is unpolished and into which unpolished and pressed countersink a minor element of a molten glass is fused to form a fused multifocal lens blank and in which the major lens blank has one refractive index and the minor element filling and fused to the convex major lens blank in the pressed, unpolished countersink therein may have a higher refractive index with the countersink being selectively spaced from the lens blank periphery.

Abstract: First and second optical fiber groups, each composed of optical fibers in layers, are held by alignment mating means, with the optical fibers placed at predetermined positions and end faces of corresponding pairs of them butted with each other. A light beam emitted from a CO.sub.2 laser is focused by a focusing optical system on the joints of the butted optical fibers. When the light beam is focused on one pair of butted optical fibers to fusion-splice them, the diameter of the focused light beam reaching the optical fibers adjacent to the irradiated ones is large so that their heating temperature by the focused light beam may not exceed their melting point. The focusing optical system and the alignment mating means are moved relative to each other to fusion-splice the butted optical fibers in succession.

Abstract: A method is described for the production of porous bodies from vitreous silica without the use of tools. Vitreous silica wool and/or threads are wound in layers on a form. After the coil has attained a certain minimum thickness, the threads of each succeeding layer are permanently bonded by heating the threads of the preceding layer at the points where the threads cross. The form is removed, and then the threads on the inside of the body are bonded together.The bodies are used for the production of high-purity blocks of silicon for solar cells.

Abstract: A semiconductor-glass composite material comprises at least one semiconductor bonded to a glass substrate, with the semiconductor layer having a strain .epsilon..ltoreq.0.3 per mil, and a dislocation density N.sub.V .ltoreq.2.times.10.sup.6 cm.sup.-2. In a process for producing the semiconductor-glass composite material, the semiconductor and glass are heated to a bonding temperature, bonded under pressure, and tempered at a temperature T.sub.a such that the viscosity of the glass at T.sub.a is 10.sup.12 to 10.sup.13.5 poise, and the following relationship holds: ##EQU1## wherein .alpha..sub.G and .alpha..sub.S are the coefficients of expansion of the glass and semiconductor, respectively, and T is temperature. The composite material is then cooled to room temperature.

Abstract: A process is disclosed for producing non-woven, yet internally cohesive, boron nitride fiber batts, suitable for use as an electric cell separator in a lithium-sulfide battery. Molten boron oxide is centrifugally spun into strands and attenuated by an annular gas stream into fibers at a controlled relative humidity. The fibers are funnelled into a chamber and subjected to a turbulent air flow, which causes random orientation and intertwining of the fibers, resulting in multiple mechanical bonds thereamong. The compacted boron oxide fiber bundle thus produced is heated in an anhydrous ammonia atmosphere to convert boron oxide in the fibers into boron nitride (BN).

Abstract: In a plant of making a blanket from fibres which are thrown or set together with polymerizable binder particles or droplets onto a perforated conveying belt, a method of cleansing consisting in: associating means for sucking air loaded with fibre dust and binder particles or droplets with means for spraying a washing liquid to be processed afterwards, providing, below said conveying belt, series of Venturi nozzles with throats of adjustable cross-section, opening into a duct connected to suction means, and distributor manifolds for spraying said washing liquid at low pressure, positioned on the one hand at the inlets of said Venturi nozzles and on the other hand downstream of the outlets thereof to provide a streaming of liquid onto all the walls of the dust removing ducts or means on which dusts and binder are likely to settle down.

Abstract: A gapped bar is formed of a pair of rectangular parallelopiped magnetic core block having coil-winding grooves jointed to each other through a medium of a non-magnetic thickness. The gapped bar is provided with a plurality of non-magnetic glass mold parts disposed to limit at least the front gap portion to a predetermined track width. Then, a head core is formed by cutting the gapped bar at the glass mold parts at a predetermined angle to the longitudinal axis of the gapped bar and then effecting required processing such as finishing of the cut surface. Finally, an annealing is effected on thus formed head core at a temperature higher than the deformation point of the glass constituting the mold glass part.

Abstract: The process includes the steps of (1) forming a pattern of indentations and adjacent boundary ridges in a base layer of glass which is heated to a temperature where it is formable but not flowing, (2) depositing electrically conducting first connecting elements on the upper surface of the base glass layer, with each first connecting element extending from an indentation to a point on an adjacent ridge, (3) positioning a solar cell into each indentation in the base glass layer in such a manner that the lower surface of the solar cell comes in electrical contact with one end of a first connecting element, (4) depositing electrically conducting second connecting elements which extend between the end of the first connecting elements on a ridge to the top surface of a solar cell in an adjacent indentation, and (5) forming a top glass layer which is in intimate contact with the product of steps 1-4.

Abstract: A glass encapsulated semiconductor diode and a method for glass encapsulation of a fusion to form a semiconductor diode is disclosed. The fusion comprises a body of semiconductor material having a PN junction therein and metal electrodes affixed to opposed major surfaces thereof. The fusion is encircled by a ring-shaped glass member with an inner surface of the ring-shaped glass member fused to an edge surface of the body of semiconductor material to form a protective layer overlying the PN junction. The ring-shaped glass member is formed and fused to the edge of the body of semiconductor material by placing the fushion and a prefabricated glass ring, preferably cut from stress relieved glass tubing, encircling the fusion in a furnace. A weight is applied to the upper surface of the prefabricated glass ring.

Abstract: Heat activated means are provided for applying areas of external pressure to the periphery of the panel portion of a cathode ray tube envelope during heat processing. The pressure is directly related to the heat cycle to which the tube envelope is subjected, and induces a state of compression in particularly the panel portion thereby minimizing the occurrence of implosions.

Abstract: The disclosure is of a method of preparing an envelope assembly including a glass tubulation in which the tubulation includes a portion of reduced diameter at which a tip-off is formed during the manufacturing process. The method comprises heating the tubulation to an elevated temperature at which surface defects heal, and subsequently securing the tubulation to the envelope in normal fashion while insuring that no further surface defects occur.