Bell Telephone Laboratories

At&t Bell Laboratories

Polaroid Corporation

American Telephone & Telegraph Co., At&t Bell Laboratories

Shobha Singh

George J Zydzik

Legrand G Van Uitert

LeGrand G Van Uitert

Irfan Camlibel

Pavle Gavrilovic

David W Johnson, Jr

Bertram Schwartz

Aland K Chin

Leo F Johnson

Hong Po

Debra Anne Fleming

Wilbur D Johnston, Jr

Judith A Long

John R Zuber

Howard Joseph Guggenheim

Albert T Macrander

William Henry Grodkiewicz

Mauro Di Domenico, Jr

William H Grodkiewicz

Joseph H Zarrabi

Mauro DiDomenico, Jr

Karen A Grim

LeGrand G Uitert

David T Ekholm

Anish K Goyal

LeGrand G VanUitert

An optical waveguide laser, preferably a fiber laser, has unintentionally incorporated impurities disposed in the lasing medium which upconvert a portion of the lasing radiation to radiation of shorter wavelength, thereby introducing defects in the medium which result in increased absorption due to photodarkening. Suitable rare-earth co-dopants are intentionally incorporated during the manufacture of the fiber for effectively shunting the upconversion process. The lifetime of the fiber laser is thereby increased.

Laser composition for preventing photo-induced damage

A diode-pumped monolithic laser is fabricated from a self-doubling host material co-doped with two ionic species, where one ionic dopant converts pump radiation to continuous radiation at a fundamental frequency and the other dopant acts as a saturable absorber to Q-switch the fundamental radiation which is then frequency doubled to produce pulsed high-intensity green light, the green light being either outputted or further frequency-doubled, into pulsed coherent UV radiation, by means of a non-linear crystal.

Miniaturized self-Q-switched frequency-doubled laser

Novel solid state gain mediums provide monolithic lasers with short cavity lengths and with the ability to efficiently lase in the lowest order TEM.sub.00 mode. Unoptimized optical power conversion efficiency of 35% has been achieved with the novel solid state gain mediums in monolithic lasers that have a cavity length as short as 0.5 mm. With proper values for the output mirror reflectivity and low loss host crystals, the optical power conversion efficiency is approximately 50%. Moreover, when in optical contact with a frequency doubling optically non linear crystal, the novel solid state gain mediums in the monolithic lasers can produce coherent visible light.

Solid state gain mediums for optically pumped monolithic laser

A crystalline material for use in a solid state tunable laser is YAG:Mn wherein the Mn is predominantly trivalent. The laser is tunable in the yellow-orange range (0.59-0.63 .mu.m) and the near infrared range (1.04-1.2 .mu.m).

Tunable solid state crystalline laser material

An up converting method and apparatus includes a crystalline structure responsive to light emitted from pump light for producing visible and/or ultraviolet light therefrom which is of a shorter wavelength than the pump light. This crystalline structure comprises a composition containing active ions of trivalent rare earth elements and a host material of either anhydrous rare earth halides or rare earth oxysulfides. This crystalline structure is represented by the atomic formula M.sub.(1-x) R.sub.x Z.sub.3 or M.sub.2(1-x) R.sub.2x O.sub.2 S where M comprises at least one rare earth element selected from the group comprising cerium, gadolinium, yttrium, lanthanum, and mixtures thereof, R is a dopant selected from the group comprising neodymium, thulium, erbium, holmium, samarium, and mixtures thereof, x is a value in the range from 0.005 to 1.0, and Z is a halogen selected from the group comprising chlorine, bromine, and iodine. When optically pumped, the crystalline structure produces visible and/or ultraviolet light by either a direct or indirect two step up conversion process. An electronic printing apparatus can also use the up converting crystalline structures to expose photosensitive media in the manner of this invention.

Optically pumped up converting light source

This invention is directed to a process of producing semiconductor devices which involves deposition of protective glass layers by a particle beam technique from targets of phosphosilicate glass, as well as a process for production of such targets. The phosphosilicate glass containing 1-15 mole percent P.sub.2 O.sub.5 is produced by a sol/gel technique which involves mixing of a fumed silica, with a surface area of 50-400 m.sup.2 /g, preferably about 200 m.sup.2 /g, with phosphoric acid and water to form a sol with 20-55 wt. % silica, allowing it to gel, drying at ambient conditions, dehydrating at about 650.degree. C. in an atmosphere of an inert gas and chlorine and fluorine containing gases, heating up at a certain rate of from 100.degree. to 180.degree. C. per hour to a peak sintering temperature below 1200.degree. C. and cooling so as to produce amorphous and transparent glass suitable for use as a target. The glass layers are highly advantageous as encapsulating layers, diffusion barrier layers, etc., especially for optical type and semiconductor devices. Production of the phosphosilicate glass by the sol/gel technique is highly advantageous over the conventional melting technique, being faster and much less expensive than the latter.

Fabrication of semiconductor devices using phosphosilicate glasses

This invention is directed to the fabrication of semiconductor devices, especially those comprising III-V and II-VI compound semiconductor materials, and involves Rapid Thermal Annealing (RTA) of semiconductor wafers, especially those implanted with a dopant(s). The invention is also concerned with a black-box implement used in combination with the RTA. The process includes enclosing a wafer to be annealed within a 'black-box' comprising components of a black body material and subjecting the black box with the wafer therein to an RTA. In a preferred embodiment the RTA comprises (a) a pre-anneal step which includes heating to a temperature and for a period sufficient to preheat the wafer so as to reduce thermal shock due to a main annealing step, (b) the main annealing step being at a temperature and for a period sufficient to remove damage caused to said surface by the dopant implantation and to activate implanted dopant, and (c) a post-anneal step carried out at a temperature and for a period sufficient to relieve stresses which may result from the main-annealing step. The combined use of the RTA and the black box leads to wafers substantially free or slip lines and with reproducibly high mobilities and uniform activation.

Procedure for rapid thermal annealing of implanted semiconductors

Epitaxial layers of semi-insulating InP grown by MOCVD on conducting InP wafers make excellent substrates for III-V semiconductor devices. Particularly appealing is the low defect density obtained because of the conducting InP wafers and excellent insulating characteristics of the semi-insulating InP layer. The invention is a procedure for doping the insulating layer by ion implantation. Such a procedure is unusually advantageous for fabricating a variety of devices including MISFETs, MESFETs and JFETs.

Method of making indium phosphide devices

A fabrication technique is described for making various devices in which a type of glass is used as a surface protection layer. The glass layers are put down by particle bombardment (generally sputtering or e-beam bombardment) of a phosphorus-containing silicate glass target. Devices with such layers are also described. Such glass layers are highly advantageous as encapsulating material, diffusion barrier layers, etc., particularly for optical type devices and certain semiconductor devices. Particularly important is the preparation procedure for the glass target used in the bombardment process. The glass layers are moisture stable, act as excellent barriers against diffusion, and are usable up to quite high temperatures without cracking or peeling. The glass layers also provide long-term protection against atmosphere components including water vapor, oxygen, atmosphere pollution contaminants, etc.

Fabrication of devices using phosphorus glasses

Proposed is a method of fabricating III-V and II-VI compound semiconductors and a resulting product where there is formed on the surface a coating which can function as a diffusion mask and/or a passivation layer. The coating is a silicon layer deposited by a method which does not damage the semiconductor surface.

Coating of III-V and II-VI compound semiconductors

The invention is a process for putting down coatings of aluminum oxide on optical surfaces using electron-beam deposition in an oxygen-enriched atmosphere. Particularly good results are obtained when oxygen is flowed over or directed at the surface to be coated. Such coatings have extremely low losses compared to many conventional optical coatings and are particularly useful for anti-reflection coatings on various devices. In particular, for optical devices with indium phosphide surfaces operating at wavelengths near 1.3 .mu.m, the optical properties of aluminum oxide coatings are near optimum for anti-reflection coatings and the thermal expansion characteristics are a close match to those of indium phosphide.

Process for making optical INP devices

A process is described for doping compound semiconductors using a metal fluoride (e.g., ZnF.sub.2) as the source of dopant. The anhydrous metal fluoride is put down on the surface of the compound semiconductor, capped with a suitable encapsulant and heat treated to promote the diffusion. The heat treatment can be carried out in air without danger of surface damage to the compound semiconductor. Also, the diffusion is better controlled as to depth of diffusion and boundary delineation.

Diffusion procedure for semiconductor compound

A process is described for fabricating various optical devices including photodiodes in which a protective dielectric layer is put down on the surface of the device prior to heating to temperatures over about 250-300 degrees C. Such devices have excellent performance characteristics including low dark current and low noise figures.

Preparation of photodiodes

A fabrication technique is described for making various devices in which a certain type of glass is used as a surface protection layer. The glass layers are formed by particle bombardment (generally sputtering or E-beam) of a glass target. Devices with such surface layers are also described. Such glass layers are highly advantageous as encapsulating layers, diffusion barrier layers, etc., particularly for optical type devices and certain semiconductor devices. Particularly important is the preparation procedure for the glass target used in the bombardment process. The glass layers are moisture stable, act as excellent barriers against diffusion, and are usable up to quite high temperatures (i.e., in diffusion doping procedures) without cracking or peeling. The glass layers also provide long-term protection against atmosphere components including water vapor, oxygen, atmosphere pollution contaminants, etc., and can be removed by standard etching techniques.

Fabrication procedure using arsenate glasses

A fabrication technique is described for making various devices in which a type of glass is used as a surface protection layer. The glass layers are put down by particle bombardment (generally sputtering) of a borosilicate glass target. Devices with such surface layers are also described. Such glass layers are highly advantageous as encapsulating material, diffusion barrier layers, etc., particularly for optical type devices and certain semiconductor devices. Particularly important is the preparation procedure for the glass target used in the bombardment process. The glass layers are moisture stable, act as excellent barriers against diffusion, and are usable up to quite high temperatures without cracking or peeling. The glass layers also provide long-term protection against atmosphere components including water vapor, oxygen, atmosphere pollution contaminants, etc.

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Summit, NJ, United States of America

Shobha Singh