26440results about "Laser details" patented technology

A transistor is provided, which is entirely and partially transparent by the use of a transparent channel layer made of zinc oxide or the like. A channel layer 11 formed of a transparent semiconductor such as zinc oxide ZnO. A transparent electrode is used for all of a source 12, a drain 13 and a gate 14, or a part of them. As the transparent electrode, a transparent conductive material such as conductive ZnO doped with, for example, group III elements is used. As a gate insulating layer 15, a transparent insulative material such as insulative ZnO doped with elements capable of taking a valence of one as a valence number or group V elements is used. If a substrate 16 must be transparent, for example, glass, sapphire, plastic or the like can be used as a transparent material.

A semiconductor device having excellent crystallinity and excellent electric characteristics includes a ZnO thin film having excellent surface smoothness. ZnO-based thin films (an n-type contact layer, an n-type clad layer, an active layer, a p-type clad layer, and a p-type contact layer) primarily including ZnO are formed sequentially by an ECR sputtering method or other suitable method on a zinc-polar surface of a ZnO substrate. A transparent electrode and a p-side electrode are formed by an evaporation method or other suitable method on a surface of the p-type contact layer, and an n-side electrode is formed on an oxygen-polar surface of the ZnO substrate.

A method for making a laser driver circuit for burst mode is described. The method includes the following steps: First, a continuous mode laser driver circuit is selected, the chip having a temperature compensation output, a bias current setting input, and a reference current setting input. Next, the temperature compensation signal is converted to a reference current setting signal via a first bias adjustment circuit, and the reference current setting signal is input to the reference current setting input. Then, the bias current setting input is connected to ground via a second bias adjustment circuit. The reference current setting signal automatically adjusts the high level and the low level of the eye diagram of the laser according to the environmental temperature, so that the high level and the low level are kept stable to reduce the bit error rate in transmission.

PCT No. PCT / JP98 / 01640 Sec. 371 Date Dec. 9, 1998 Sec. 102(e) Date Dec. 9, 1998 PCT Filed Apr. 9, 1998 PCT Pub. No. WO98 / 47170 PCT Pub. Date Oct. 22, 1998A method of growing a nitride semiconductor crystal which has very few crystal defects and can be used as a substrate is disclosed. This invention includes the step of forming a first selective growth mask on a support member including a dissimilar substrate having a major surface and made of a material different from a nitride semiconductor, the first selective growth mask having a plurality of first windows for selectively exposing the upper surface of the support member, and the step of growing nitride semiconductor portions from the upper surface, of the support member, which is exposed from the windows, by using a gaseous Group 3 element source and a gaseous nitrogen source, until the nitride semiconductor portions grown in the adjacent windows combine with each other on the upper surface of the selective growth mask.

The present invention relates to optical confinements, methods of preparing and methods of using them for analyzing molecules and / or monitoring chemical reactions. The apparatus and methods embodied in the present invention are particularly useful for high-throughout and low-cost single-molecular analysis.

Holey optical fibers (e.g. photonic fibers, random-hole fibers) are fabricated with quantum dots disposed in the holes. The quantum dots can provide light amplification and sensing functions, for example. When used for sensing, the dots will experience altered optical properties (e.g. altered fluorescence or absorption wavelength) in response to certain chemicals, biological elements, radiation, high energy particles, electrical or magnetic fields, or thermal / mechanical deformations. Since the dots are disposed in the holes, the dots interact with the evanescent field of core-confined light. Quantum dots can be damaged by high heat, and so typically cannot be embedded within conventional silica optical fibers. In the present invention, dots can be carried into the holes by a solvent at room temperature. The present invention also includes solid glass fibers made of low melting point materials (e.g. phosphate glass, lead oxide glass) with embedded quantum dots.

The LED brightness control system for a wide range of luminance control includes a brightness control module that provides a pulse width modulation (PWM) control signal and a peak current control signal. A pulse width modulation (PWM) converter circuit receives the PWM control signal and converts it to a PWM signal. A multiplier receives the PWM signal and the peak current control signal from the brightness control module and multiplies the same to provide a light emitting diode (LED) current control signal with a variable “on” time as well as variable “on” level. A voltage-controlled current source utilizes the LED current control signal and an LED current feedback signal for providing an LED current. An LED illuminator array receives the LED current. A current sensing element connected to the LED illuminator array for providing an LED current feedback signal representing LED peak current. The voltage-controlled current source controls a drive voltage to the LED illuminator array at a commanded level.

In one aspect the invention provides a method for laser induced breakdown of a material with a pulsed laser beam where the material is characterized by a relationship of fluence breakdown threshold (Fth) versus laser beam pulse width (T) that exhibits an abrupt, rapid, and distinct change or at least a clearly detectable and distinct change in slope at a predetermined laser pulse width value. The method comprises generating a beam of laser pulses in which each pulse has a pulse width equal to or less than the predetermined laser pulse width value. The beam is focused to a point at or beneath the surface of a material where laser induced breakdown is desired.The beam may be used in combination with a mask in the beam path. The beam or mask may be moved in the x, y, and Z directions to produce desired features. The technique can produce features smaller than the spot size and Rayleigh range due to enhanced damage threshold accuracy in the short pulse regime.

A system, a device and a method for accelerating packet filtration by supplementing a firewall with a pre-filtering module. The pre-filtering module performs a limited set of actions with regard to the packets, according to whether the packets are received from a connection which has been previously permitted by the firewall. If the packets are received from such a permitted connection, then the pre-filtering module forwards the packets to their destination, optionally performing one or more actions on the packets. Otherwise, the packets are forwarded to the firewall for handling. Preferably, once the firewall has transferred responsibility for the connection to the pre-filtering module, or "off-loaded" the connection, the firewall does not receive further packets from this connection until a timeout occurs for the connection, or a packet is received with particular session-control field values, such that the connection is closed. Optionally and preferably, the pre-filtering module is implemented as hardware.

By forming MOSFETs on a substrate having pre-existing ridges of semiconductor material (i.e., a “corrugated substrate”), the resolution limitations associated with conventional semiconductor manufacturing processes can be overcome, and high-performance, low-power transistors can be reliably and repeatably produced. Forming a corrugated substrate prior to actual device formation allows the ridges on the corrugated substrate to be created using high precision techniques that are not ordinarily suitable for device production. MOSFETs that subsequently incorporate the high-precision ridges into their channel regions will typically exhibit much more precise and less variable performance than similar MOSFETs formed using optical lithography-based techniques that cannot provide the same degree of patterning accuracy. Additional performance enhancement techniques such as pulse-shaped doping and “wrapped” gates can be used in conjunction with the segmented channel regions to further enhance device performance.

Apparatus for dynamic surface annealing of a semiconductor wafer includes a source of laser radiation emitting at a laser wavelength and comprising an array of lasers arranged in rows and columns, the optical power of each the laser being individual adjustable and optics for focusing the radiation from the array of lasers into a narrow line beam in a workpiece plane corresponding to a workpiece surface, whereby the optics images respective columns of the laser array onto respective sections of the narrow line beam. A pyrometer sensor is provided that is sensitive to a pyrometer wavelength. An optical element in an optical path of the optics is tuned to divert radiation emanating from the workpiece plane to the pyrometry sensor. As a result, the optics images each of the respective section of the narrow line beam onto a corresponding portion of the pyrometer sensor. The apparatus further includes a controller responsive to the pyrometry sensor and coupled to adjust individual optical outputs of respective columns of the laser array in accordance with outputs of corresponding portions of the pyrometry sensor.

An inventive semiconductor laser diode includes a Group III nitride semiconductor layered structure having a major crystal growth plane defined by a non-polar or semi-polar-plane. The Group III nitride semiconductor layered structure includes: a p-type cladding layer and an n-type cladding layer; an In-containing p-type guide layer and an In-containing n-type guide layer held between the p-type cladding layer and the n-type cladding layer; and an In-containing light emitting layer held between the p-type guide layer and the n-type guide layer.

A method and apparatus for wireless power beaming consisting of a transmitter assembly (20), free space (40), and an optical-to-electric assembly (50). The transmitter assembly (20) has eye-safe lasers (26) that create a beam of light (90). The beam of light goes through free space (40) and impinges upon the surface of optical-to-electric assembly (50). Optical-to-electric assembly (50) has power conversion photodiode(s) (54) to convert the energy in the light (90) into electricity. Power Accounting (14) accounts for the power in the beam and controls the lasers to turn them off whenever radiation is not accounted for in the system.

A method of forming a partially etched nitride-based compound semiconductor crystal layer includes the following steps. A non-crystal layer of a nitride-based compound semiconductor is formed. At least a part of the non-crystal layer is then etched to form a partially etched non-crystal layer before the partially etched non-crystal layer is crystallized to form a partially etched nitride-based compound semiconductor crystal layer.

A laser diode, grown on a miscut nonpolar or semipolar substrate, with lower threshold current density and longer stimulated emission wavelength, compared to conventional laser diode structures, wherein the laser diode's (1) n-type layers are grown in a nitrogen carrier gas, (2) quantum well layers and barrier layers are grown at a slower growth rate as compared to other device layers (enabling growth of the p-type layers at higher temperature), (3) high Al content electron blocking layer enables growth of layers above the active region at a higher temperature, and (4) asymmetric AlGaN SPSLS allowed growth of high Al containing p-AlGaN layers. Various other techniques were used to improve the conductivity of the p-type layers and minimize the contact resistance of the contact layer.

Optical resonators that are enhanced with photoluminescent phosphors and are designed and configured to output light at one or more wavelengths based on input / pump light, and systems and devices made with such resonators. In some embodiments, the resonators contain multiple optical resonator cavities in combination with one or more photoluminescent phosphor layers or other structures. In other embodiments, the resonators are designed to simultaneously resonate at the input / pump and output wavelengths. The photoluminescent phosphors can be any suitable photoluminescent material, including semiconductor and other materials in quantum-confining structures, such as quantum wells and quantum dots, among others.

Methods for forming compositions comprising a single-phase rare-earth dielectric disposed on a substrate are disclosed. In some embodiments, the method forms a semiconductor-on-insulator structure. Compositions and structures that are formed via the method provide the basis for forming high-performance devices and circuits.

An information processor of a high reliability and a high recording density, and a blue color, blue-violet color and violet color based semiconductor light emitting device operable at a low threshold current density, used for the same, are provided. An optical information processor of a high reliability and a high recording density enables a moving picture, such as a high-definition television picture, to be recorded and reproduced satisfactorily. A barrier layer in a quantum-well active layer of a semiconductor light emitting device is doped with n-type impurities at a high density. Alternatively, the face orientation of a quantum-well active layer of a semiconductor light emitting device is a plane inclined from the (0001) plane, whereby the threshold current value of the semiconductor light emitting device can be decreased. The semiconductor light emitting device is typified by a gallium nitride based compound semiconductor laser device.

A signal router is described. The signal router includes a switching matrix, an error detector and a controller. The switching matrix includes a first number of inputs and a second number of outputs, and is configured to receive an information stream. The error detector is coupled to one of the second number of outputs, and is configured to generate error information by virtue of being configured to detect errors in the information stream. Likewise, the controller is coupled to the switching matrix and error detector. The controller is configured to select one of the first number of inputs, receive error information from the error detector, and configure the switching matrix to couple the selected input to one of the outputs.

An optical coupler for coupling light from at least two input fibers into one output fiber and a method of fabricating and use of an optical coupler. The coupler comprises a) an input section comprising an output end face at one end of the bundling-length of input fibers; and b) an output section comprising an output fiber comprising a confining region for confining light propagated in the input fibers and a surrounding cladding region and having an input end face; wherein the output end face of said input section is optically coupled to the input end face of the output section and at least the confining region of the output fiber is tapered down from a first cross sectional area at the input end face to a second, smaller cross sectional area over a tapering-length of the output fiber.

Optical gain of a nonpolar or semipolar Group-III nitride diode laser is controlled by orienting an axis of light propagation in relation to an optical polarization direction or crystallographic orientation of the diode laser. The axis of light propagation is substantially perpendicular to the mirror facets of the diode laser, and the optical polarization direction is determined by the crystallographic orientation of the diode laser. To maximize optical gain, the axis of light propagation is oriented substantially perpendicular to the optical polarization direction or crystallographic orientation.

An optical device having a structured active region configured for one or more selected wavelengths of light emissions and formed on an off-cut m-plane gallium and nitrogen containing substrate.

A nitride-based semiconductor device includes a substrate, a first step portion formed on a main surface side of a first side end surface of the substrate, a second step portion formed on the main surface side of a second side end surface substantially parallel to the first side end surface on an opposite side of the first side end surface and a nitride-based semiconductor layer whose first side surface is a (000-1) plane starting from a first side wall of the first step portion and a second side surface starting from a second side wall of the second step portion on the main surface.

An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the header and data payload propagate through network elements with the same path and the associated delays. The header routing information has sufficiently different characteristics from the data payload so that the signaling header can be detected without being affected by the data payload, and that the signaling header can also be removed without affecting the data payload. The signal routing technique can be overlaid onto the conventional network elements in a modular manner using two types of applique modules. The first type effects header encoding and decoding at the entry and exit points of the data payload into and out of the network; the second type effects header detection at each of the network elements.

A neutral particle beam processing apparatus comprises a workpiece holder (20) for holding a workpiece (X), a plasma generator for generating a plasma in a vacuum chamber (3), an orifice electrode (5) disposed between the workpiece holder (20) and the plasma generator, and a grid electrode (4) disposed upstream of the orifice electrode (5) in the vacuum chamber (3). The orifice electrode (5) has orifices (5a) defined therein. The neutral particle beam processing apparatus further comprises a voltage applying unit for applying a voltage between the orifice electrode (5) and the grid electrode (4) via a dielectric (5b) to extract positive ions from the plasma generated by the plasma generator and pass the extracted positive ions through the orifices (5a) in the orifice electrode (5).

A photonic crystal optical switch having a periodic dielectric structure including at least one input waveguide. First and second waveguide arms branch from the input waveguide in which the relative optical path lengths of electromagnetic radiation within the arms are controlled by stimuli. At least one output waveguide that combines the electromagnetic radiation propagating within the first and second waveguide arms.

An optical device includes a gallium nitride substrate member having an m-plane nonpolar crystalline surface region characterized by an orientation of about −2 degrees to about 2 degrees towards (000-1) and less than about 0.5 degrees towards (11-20). The device also has a laser stripe region formed overlying a portion of the m-plane nonpolar crystalline orientation surface region. A first cleaved c-face facet is provided on one end of the laser stripe region, and a second cleaved c-face facet is provided on the other end of the laser stripe region.

An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where −15<x<−1 and 1<x<15 degrees.

In one aspect the invention relates to a frequency varying wave generator. The generator includes a gain element adapted to amplify a wave having a wavelength; a time varying tunable wavelength selective filter element in communication with the gain element, the tunable filter element adapted to selectively filter waves during a period T; and a feedback element in communication with the tunable filter element and the gain element, wherein the tunable wavelength selective filter element, the gain element and the feedback element define a circuit such that the roundtrip time for the wave to propagate through the circuit is substantially equal to a non-zero integer multiple of the period T.