Abstract: A method of performing heteroepitaxy comprises exposing a substrate to a carrier gas, a first precursor gas, a Group II/III element, and a second precursor gas, to form a heteroepitaxial growth of one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN on the substrate; wherein the substrate comprises one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN; wherein the carrier gas is H2, wherein the first precursor is HCl, the Group II/III element comprises at least one of Zn, Cd, Hg, Al, Ga, and In; and wherein the second precursor is one of AsH3 (arsine), PH3 (phosphine), H2Se (hydrogen selenide), H2Te (hydrogen telluride), SbH3 (hydrogen antimonide), H2S (hydrogen sulfide), and NH3 (ammonia). The process may be an HVPE (hydride vapor phase epitaxy) process.

Abstract: Apparatus and methods to monitor optical intensity within optical fibers in a substantially non-invasive fashion are disclosed. Optical monitors are comprised of thin, conductive coatings applied to transparent substrates and patterned to form pairs of resistive elements, one of which intersects an optical beam propagating through optical fiber cables. Systems of distributed optical monitors interconnecting optical fiber links enable automated monitoring of the optical status across a communications networks.

Abstract: A two-dimensional, temporally modulated electromagnetic wavefield, preferably in the ultraviolet, visible or infrared spectral range, can be locally detected and demodulated with one or more sensing elements. Each sensing element consists of a resistive, transparent electrode (E) on top of an insulated layer (O) that is produced over a semiconducting substrate whose surface is electrically kept in depletion. The electrode (E) is connected with two or more contacts (C1; C2) to a number of clock voltages that are operated synchronously with the frequency of the modulated wavefield. In the electrode and in the semiconducting substrate lateral electric fields are created that separate and transport photogenerated charge pairs in the semiconductor to respective diffusions (D1; D2) close to the contacts (C1; C2).

Abstract: A photoelectric transducing element comprising (a) a substrate; (b) first electrode provided on said substrate; (c) first contact layer to form an ohmic contact with said first electrode with respect to electric charge in at least one polarity; (d) a photoconductive layer provided in contact with said first contact layer and composed of an amorphous material containing silicon atom as a matrix and hydrogen atom, or halogen atom, or both, at a ratio of 1 to 30 atomic % with respect to said silicon atom; (e) second contact layer provided in contact with said photoconductive layer; and (f) second electrode to form an ohmic contact with said second contact layer with respect to said charge.

Abstract: To achieve constant brightness from the chlorine stage of a wood pulp bleaching system, the chlorine addition rate is controlled by two white light photosensors positioned, respectively, 1-5 minutes downstream of the chlorine addition point and immediately prior to the chlorine washers. A relative error signal from the late photosensor is cascaded upon the set-point of a signal differentiator for the early photosensor to generate a chlorine valve control signal. The photosensors comprise selenium photocells positioned against a transparent stock conduit window and reflection illuminated by a low power white light source positioned more remotely from the window than the photocell at a discreet offset angle relative thereto. The white light is directed past the photocells, through the windows and into the flow stream; the photocells being responsive to the relative magnitude of white light reflected from the wood pulp. The power generated from the photocell is correlated to the pulp brightness.

Abstract: An improved semiconductor device is described which utilizes stable, slow diffusing resilient contacts that also serve as a suspension support for a semiconductor body.