Abstract: An amplifier including a first input for a first at least two input signals having mutually distinct wavelengths, a first output for a first at least two output signals, the first at least two output signals having said mutually distinct wavelengths, a first circulator including an input port coupled to the first input, an output port coupled to the first output, and an intermediate port coupled to a first end of a selective reflection circuit, and, a second circulator including an intermediate port coupled to a second end of the selective reflection circuit, an output port coupled to a first selective splitter, and an input port coupled to a second selective splitter, wherein the first selective splitter and the second selective splitter are centered about a first selected wavelength amongst the mutually distinct wavelengths.

Abstract: An amplifier system includes: (i) a distributed Raman fiber amplifier and; (ii) a discrete Raman fiber amplifier that includes dispersion compensated fiber. The discrete Raman fiber amplifier is operatively connected to the distributed Raman fiber amplifier and amplifies signals received from the distributed Raman fiber amplifier. In one embodiment, at least one source of pump signal is coupled to the distributed and to the discrete Raman fiber amplifier. The distributed Raman fiber amplifier and the discrete Raman fiber amplifier in this embodiment share optical pump power provided by the shared pump. In one embodiment of the present invention an Erbium doped fiber amplifier (EDFA) is operatively connected to a discrete Raman fiber amplifier and the Erbium dope fiber amplifier amplifies signals received from the discrete Raman fiber amplifier.

Abstract: An add-drop wavelength filter is described which separates specific wavelength components from optical signals propagating through an optical waveguide or adds specific wavelength components thereto. In general, add-drop wavelength filters serve to separate or add specific channels in channels comprising several different wavelengths in a wavelength division optical communication system, and require good wavelength selectivity, stability and etc. Up to now, several types of add-drop wavelength filters are proposed, however disadvantageously they were not stable or were difficult to fabricate. The add-drop wavelength filter of the present invention comprising a mode discrimination coupler, Bragg gratings in which mode conversion occurs and etc., utilizes mode conversion in a dual mode waveguide and has low loss and stability.

Abstract: The present invention relates to an optical fiber having a normalized frequency applicable to a broadband optical device, and to a broadband, polarization-independent, low-loss optical fiber device made by using the aforementioned optical fiber. The optical fiber of the present invention has a normalized frequency value V, structural parameters of which including a core radius, a core refractive index and a cladding refractive index are adjusted to minimize the beat dispersion between first and second modes in a predetermined frequency range. Various optical fiber devices may be achieved if the aforementioned optical fiber is used along with acoustic wave generating means and a mode dropper or a mode selective coupler.

Abstract: A method for supporting non-assignable signals during formal verification of a circuit design includes providing a propagation logic for non-assignable signals and identifying a relevant cone in a circuit design, where the relevant cone determined by a property to verify. The method also includes designating one or more signals in the circuit design as non-assignable signals and propagating within the relevant cone any of the designated one or more non-assignable signals using the propagation logic for non-assignable signals. The method further includes ensuring, if a counter-example disproving the property exists, that the counter-example does not comprise any of the one or more designated non-assignable signals. A formal verification system that supports the designation of non-assignable signals comprises a non-assignable signal truth table and a proof engine. The non-assignable signal truth table specifies a propagation logic for non-assignable signals.

Abstract: A method of fabricating a fused-type directional coupler that can be made in a simple manner. The present invention is characterized in that a pair of optical fibers satisfying a particular phase match condition are previously selected to form a fused-type directional coupler. The two optical fibers are prepared by respectively tapering and etching two identical optical fibers. The present invention can be applied to fabrication of mode-selective directional couplers utilizing symmetrical high-degree modes such as LP02 mode as well as fabrication of mode-selective directional couplers utilizing asymmetrical high-degree modes such as LP11 mode.

Abstract: An optical system for a scanning probe microscope provides both an optical on-axis view and an optical oblique view of the sample by means of two optical paths each providing an image to a CCD camera via an auto-zoom lens. A shutter alternately blocks the image of either view from reaching the auto-zoom lens. The CCD camera provides the optical image to a video display which also displays the scanning probe image, thus eliminating the need for eyepieces and allowing easy viewing of both the optical and scanning probe images simultaneously.

Abstract: Disclosed herein are a system and method for using a remote terminal to control processes executing on a client terminal by transmitting data to the client terminal emulating keystroke inputs at the client terminal. A remote control application program executing at the remote terminal initiates the transmission of a message for emulating keystroke inputs to the client terminal. The remote terminal also executes an operating system having logic for responding to a detection of any one combination of keystrokes of a set of predetermined combinations of keystrokes, independently of any application program executing on the remote terminal. While the remote control application is active, the remote terminal inhibits the operating system from responding to detected keystrokes and transmits a message to the client terminal emulating an input of the detected keystrokes at the client terminal.

Abstract: An apparatus or method for testing the setup time and hold time specifications of a chip. An apparatus according to the invention would include a first chip, a second chip, and multiple links coupling the first chip to the second chip. One of the links carries a clock signal between the chips. Other links carrying data have propagation delays different from the propagation delay of the link carrying the clock signal. The relation of the delays for the data links to the delay for the clock link determines a particular setup and/or hold time tested.

Abstract: A central processing unit having an extension instruction comprises a memory address, an offset and a fixed length instruction of varying immediate data. The central processing unit comprises a general register, a special register, a register file constituted as an inner register, a function block for executing the calculation function; an instruction register for memorizing the instruction, a control block for generating/outputting a control signal to the instruction register and a plurality of status flags, in which the special register enables access by a programmer and includes an extension data field for memorizing extension data or an extension register having the extension data field as one element and an extension flag for changing its status when the instruction memorizing the extension data in the extension register is executed and having one or a plurality of bits that is accessible to a programmer.

Abstract: A modified universal exhaust gas oxygen sensor, referred to herein as a CEGA sensor, is provided which can be used to measure the concentration of a variety of components of a gaseous fuel emission including CO, CO2, O2, H2, and H2O. The CEGA sensor-employs at least one additional electrode on a ceramic substrate which possess a different catalytic activity relative to the electrodes that normally found on a UEGO sensor. The ceramic substrate may be made of any suitable ceramic and is preferably made of zirconia. The difference in catalytic activity between the additional electrode(s) and the electrodes native to the UEGO sensor create an oxygen gradient which enables a measure of combustion completeness to be calculated. In combination with an air/fuel ratio measured by the sensor, the concentrations of different components in the emission can be calculated.

Abstract: A modified universal exhaust gas oxygen sensor, referred to herein as a CEGA sensor, is provided which can be used to measure the concentration of a variety of components of a gaseous fuel emission including CO, CO2, O2, H2, and H2O. The CEGA sensor-employs at least one additional electrode on a ceramic substrate which possess a different catalytic activity relative to the electrodes that normally found on a UEGO sensor. The ceramic substrate may be made of any suitable ceramic and is preferably made of zirconia. The difference in catalytic activity between the additional electrode(s) and the electrodes native to the UEGO sensor create an oxygen gradient which enables a measure of combustion completeness to be calculated. In combination with an air/fuel ratio measured by the sensor, the concentrations of different components in the emission can be calculated.

Abstract: A method and apparatus for homoepitaxial growth of freestanding, single bulk crystal Gallium Nitride (GaN) are provided, wherein a step of nucleating GaN in a reactor results in a GaN nucleation layer having a thickness of a few monolayers. The nucleation layer is stabilized, and a single bulk crystal GaN is grown from gas phase reactants on the GaN nucleation layer. The reactor is formed from ultra low oxygen stainless steel.