Abstract: This invention embodies an optical medium which consists of polar, multi-monomolecular layers of organic dye molecules with a net polar orientation, considerable second order optical nonlinearity, and excellent thermal stability. The medium is prepared by repeated sequential depositions on a surface of multivalent metal ions, e.g. Zr.sup.4+, and organic dyes terminated with an acidic functionality, e.g. a phosphonic acid, followed by activation of the surface for the next deposition sequence. The monolayers are deposited in the form of a multilayer film containing up to 1000 or more monolayers. The monolayers are deposited from liquid solutions; therefore they may be deposited on substrates having diverse topography and configurations. Second harmonic generation (SHG) analysis establishes that the multilayers have uniform polar order which does not decrease with increasing numbers of monolayers in the film.

Abstract: This invention pertains to integration of nonlinear parametric waveguide spectrometer with polyimide waveguide focusing mirror. The waveguide spectrometer uses nonlinear counter-propagating .chi..sup.2 interaction to simulate the action of a grating and produce the required chromatic dispersion. To map the near-field to far-field and separate different wavelength components, an organic-dielectric (e.g. a polyimide/SiO.sub.2) guide and a 45.degree. RIE etched mirror were fabricated to simulate a concave focusing integrated mirror. The measured spot size at the focal plane of the mirror was about 0.7 .mu.m corresponding to about 1.6 Angstroms spectral resolution in agreement with the theoretical prediction. The device has good spectral resolution; however, the conversion efficiency is smaller than the theoretical prediction. Even with the low signal power level, the integrated deviced may be of use in applications that can take advantage of the visible output and do not require high power conversion efficiency.

Abstract: This invention pertains to a p-i-n In.sub.0.53 Ga.sub.0.47 As photodiode having an optically transparent composite top electrode consisting of a thin semitransparent metal layer from 10 to 40 nm thick and a transparent cadmium tin oxide (CTO) layer from 90 to 600 nm thick. The metal layer makes a non-alloyed ohmic contact to the semiconductor surface, acts as a barrier between the semiconductor and the CTO preventing oxidation of the semiconductor from the O.sub.2 in the plasma during reactive magnetron sputtering of the CTO layer, and prevents formation of a p-n junction between the semiconductor and CTO. The CTO functions as the n or p contact, an optical window and an anti-reflection coating. The top electrode also avoids shadowing of the active layer by the top electrode, thus allowing greater collection of incident light. Since the top electrode is non-alloyed, inter-diffusion into the i-region is not relevant, which avoids an increased dark current.

Abstract: This invention pertains to buried heterostructure lasers which have been fabricated using a single step MOCVD growth of an MQW laser structure over a pattern etched GaAs substrate. The wet chemical etching of grooves having a dovetailed cross-section and being parallel to the [011] direction in GaAs substrates produced reentrant mesas which resulted in isolated laser active regions buried by the AlGaAs cladding layer. The 250 .mu.m long uncoated lasers emit at about 1 .mu.m. Lasers with coated facets have threshold currents of 20 mA and emit >100 mW per facet under room temperature operation. The external differential quantum efficiency for currents of from 30 mA to about 50 mA is found to be nearly independent of temperature in the range of 10.degree. C. to 90.degree. C. suggesting a low temperature dependence of leakage current.

Abstract: This invention embodies a Vertical Cavity Surface Emitting Laser with a top mirror comprising at least one pair of quarterwave layers, each pair consisting of a low index of refraction layer and a high index of refraction layer, the high index of refraction layer being a semiconductor chosen from GaP and ZnS and the low index of refraction layer being chosen from borosilicate glass (BSG) CaF.sub.2,MgF.sub.2 and NaF. Especially useful in vertical cavity surface emitting lasers are mirrors formed by a stack of a plurality of pairs of GaP/BSG or ZnS/CdF.sub.2. Such mirrors have a high reflectivity characteristics required for an efficient operation of the laser. The GaP/BSG or ZnS/CaF.sub.2 mirror structure represents a considerable improvement over previous designs for VCSELs in terms of ultimate reflectivity, low loss, and post growth processing compatibility.

Abstract: Conduction band or valence band discontinuities occurring at the junction of two unipolar heterogeneous semiconductors can be eliminated by compositional grading of the heterointerface and appropriate doping of the interfacial region. The compositional potential of graded junction and an interface dipole potential generated by modulation doping of the interfacial region are selected such that they exactly compensate each other. The compositional grading of the interface is achieved by semiparabolic grading of narrow regions immediately adjacent each side of the interface. The modulation doping is achieved by doping the two materials with suitable dopants, donors for the conductance band or acceptors for the valence band, depending on the polarity of the structure. This reduces the resistance in periodic semiconductor multilayer structures leading to low-resistance distributed Bragg reflectors.

Abstract: The invention is a technique for the growth of single crystals of rare earth doped rare-earth orthosilicate crystals which may be used as the laser medium in solid-state non-semiconductor lasers. This type of laser has applications in electronics, communications, aerospace systems, and manufacturing technology where high optical output lasers are utilized. Of particular interest is the Y.sub.2-x Nd.sub.x SiO.sub.5 crystal, with x being up to 0.3, which may be efficiently pumped by a semiconductor laser, solid state non-semiconductor laser, a flashlamp or some other source of light radiation, and has been found to be operable at very high optical output. The rare-earth orthosilicate crystals are grown in accordance with this invention by a Czochralski technique from a molten mixture of constituent oxides in an inert atmosphere containing oxygen.

Abstract: This invention embodies a process for synthesizing electrodialythically palladium ammine hydroxide for use in palladium plating baths. The electrodialysis takes place in a cell with a catholyte, a product and an anolyte compartments which are divided by a fluorinated anion permselective membranes. Catholyte solution readily supplies OH ions, raw starting solution contains palladium ammine ions and anions capable of migrating into the anolyte compartment, and anolyte solution readily absorbs the anions from the raw solution. Electrodes, placed in the outer compartments, are placed no more than 5 cm apart. The process is conducted with current densities of 500 ASF or less, with 200 ASF being preferable, with current efficiencies of 50 to 90 percent, with 60-80 percent being preferable, and at bath temperatures of from above freezing to 40.degree. C., with 25.degree.-40.degree. C. being preferable.

Abstract: This invention concerns with microwave devices including resonant elements made from dielectric materials represented by the nominal formulas Ba.sub.2 Ti.sub.9 O.sub.20, BaTi.sub.4 O.sub.9, ZrTiO.sub.4 (Sn) and the like. The resonant element is produced conventionally by a process including numerous steps of mixing, drying, screening, calcining, ball milling, drying, screening or remilling and spray drying, forming and sintering. These steps may take 72 hours or more, prior to the forming step, and are labor and energy consuming. The improvement resides in the use of a reduced number of steps which include mixing precursor powders with addition of water and dispersants, spray drying or flocculating and drying the mixed formulation, forming and reactively sintering, so as to reduce the total processing time, prior to the forming step, to form about 8 to 24 hours.

Abstract: This invention is a process for etching copper sheets on insulating boards for use in fabricating multilayer printed circuit boards. The improvement resides in adding to a standard copper etching solution certain alkyltrimethyl ammonium chlorides with alkyl chain lengths ranging from 6 to 20 carbon atoms in amounts sufficient to yield intermediate kinetics behavior. Of special interest are dodecyltrimethyl ammonium chloride, hexadecyltrimethyl ammonium chloride and octadecyltrimethyl ammonium chloride present in an amount of from 0.01 to 1.0 wt %. A silicon-based antiforming agent may be added in amounts of from 0.05 to 2.0 wt. % to prevent an unacceptably large amount of foam from occurring during etching. With this formulation, the rate is mass transport controlled at low rates and almost independent of mass transport at high rates due to the inhibition of the surface reaction rate.

Abstract: Optically transparent and electrically conductive cadmium tin oxide or indium tin oxide is employed in vertical cavity surface emitting lasers for vertical current injection. Continuous wave lasing at room temperature is achieved in GaAs/AlGaAs quantum well lasers. Devices with a 10 .mu.m optical window which also serves as a vertical current injection inlet give lasing threshold currents as low as 3.8 mA. The differential series resistance is (350-450) .OMEGA. with a diode voltage of (5.1-5.6) V at the lasing threshold. Far field pattern of the laser emission is Gaussian-like with a full width at half maximum of 7.degree..

Abstract: This invention is concerned with the production of Schottky barrier gate contacts in MESFET devices. The contact is produced by wet-chemical removal of native oxide in a sealed inert gas ambient and blow-drying the wet-etched surface with the inert gas prior to deposition of gate electrode metal on GaAs by electron beam evaporation in an inert gas ambient. Use of Pt, due to its higher metal work function, as the gate contact metal results in a Schottky barrier height of 0.98 eV for Pt on n-type GaAs. This is considerably higher than the barrier height of conventionally processed TiPtAu contacts (0.78 eV).

Abstract: The present invention is an electronic circuit, such as a Hybrid Integrated Circuit (HIC), having an element mounted on a suitable support base, and a self-adjusting heat sink mounted on the element. A heat spreader is located in spaced relationship with the support base. The heat spreader may be a plate of conductive material provided especially or may form a part of a housing enclosing the HIC. The heat sink has a bottom portion secured to the element and at least one flange for conducting heat energy to the heat spreader. Each flange includes an upright segment projecting from the bottom portion of the heat sink toward the heat spreader, a free end segment bent away from the heat spreader and a knee-bend segment intermediate the upright segment and the free-end segment and adjacent to the heat spreader.

Abstract: This invention provides an in situ monitoring technique and apparatus for chemical/mechanical planarization end point detection in the process of fabricating semiconductor or optical devices. Fabrication of semiconductor or optical devices often requires smooth planar surfaces, either on the surface of a wafer being processed or at some intermediate stage e.g. a surface of an interleaved layer. The detection in the present invention is accomplished by means of capacitively measuring the thickness of a dielectric layer on a conductive substrate. The measurement involves the dielectric layer, a flat electrode structure and a liquid interfacing the article and the electrode structure. Polishing slurry acts as the interfacing liquid. The electrode structure includes a measuring electrode, an insulator surrounding the measuring electrode, a guard electrode and another insulator surrounding the guard electrode.

Abstract: This invention is a new optical packaging and interconnection technology which is particularly effective in not only addressing the problem of attaching fiber pigtails to glass waveguide silicon devices, but also in isolating these waveguide devices from the deleterious effects of their external environment. An important aspect of the invention lies in the novel realization that the foregoing objectives may be achieved by covering the device with a thin silica coverplate affixed with a low index epoxy, which act as an extended cladding layer for optically confining the optical radiation below the coverplate.

Abstract: This invention is a semiconductor vertical cavity surface emitting laser comprising a lasing cavity with an active layer, a bottom (rear) mirror and a top (front) mirror, and a front and rear electrodes for applying excitation current in direction substantially parallel to the direction of optical propagation. In accordance with this invention the front mirror comprises a thin, semitransparent metal layer which also acts as the front electrode. The metal layer is upon a highly doped layer forming a non-alloyed ohmic contact. The metal is selected from Ag and Al and is deposited in thickness ranging from 5 to 55 nm. The VCSEL is a semiconductor device wherein the semiconductor material is a III-V or II-VI compound semiconductor. For a VCSEL with GaAs active layer, the light output from the front metal mirror/electrode side yields a high external differential quantum efficiency as high as 54 percent. This is the highest quantum efficiency obtained in VCSEL structures.

Abstract: A method of for manufacturing a coated optical fiber includes depositing a conductive coating on the optical fiber and measuring a value of conductance of that coating. Featured within the manufacturing method is a method for measuring the thickness of the conductive coating on an insulator, e.g., carbon on an optical fiber, including the following steps. An electromagnetic field is established by an input signal. The conductively coated insulator is moved through the energized electromagnetic field. The conductive coating on the insulator is oriented with respect to the electric field so that their interaction increases transmission loss from input to output. An output signal is extracted from the electromagnetic field. From changes in the output signal with respect to a predetermined standard, or reference, the conductance and the thickness of the conductive coating are determined.

Abstract: A thermally balanced electronic circuit having an element mounted on a suitable support base, a heat-sink having a bottom portion contacting the element and at least one flange projecting from the bottom portion, and a stress-balancing insert positioned on the bottom portion of the heat-sink and at least partially coextensive with the element, said bottom portion of the heat sink being secured to the element and to the insert by means of an adhesive. The insert is of a material having a coefficient of thermal expansion (TCE), .alpha..sub.1, different from the TCE, .alpha..sub.2, of material of the heat sink. The TCE of the material of the insert may be intermediate the material of the TCE of the heat sink and the TCE, .alpha..sub.3, of the material of the element. Preferably, the TCE of the material of the insert approximately matches or is equal to the TCE of the material of the element. The element, the bottom portion of the heat-sink, the insert and the adhesive layers form a balanced "sandwich" structure.

Abstract: 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.

Abstract: A process for manufacturing an optical fiber includes the steps of heating and drawing material from a hot optical fiber preform; depositing a conductive coating (especially carbon) on the moving optical fiber; putting a heat curable liquid material on the moving optical fiber; and curing the heat curable liquid material by inductively heating the conductive coating on the moving optical fiber in an electromagnetic field. Heat induced into the conductive coating by energy from the field is conducted from the conductive coating to the heat curable material. The optical fiber continuously moves through the steps of the process without any physical contact.