Other

Northrop Grumman Systems Corporation

Trw Limited

David C Scott

Timothy A Vang

Srinath Kalluri

Wenshen Wang

Elizabeth Twyford Kunkee

David V Forbes

Thomas Jin-Ming Jung

Joseph Morais

Compositions containing free amino acids have been found to provide effective pain relief in less than five minutes following administration. Suitable compositions include free leucine, free isoleucine, and free valine in a leucine:isoleucine:valine weight ratio of about 1.9:1:1.3. Palatability is improved by the addition of free glycine, such that sweeteners or other flavorants are not necessary. The composition can be a two part formulation in which certain amino acids are provided as a capsule or tablet in order to improve palatability.

Free amino acid preparation and uses thereof

The present photonic RF generation and distribution system provides a system and method for distributing an RF output signal. The photonic RF distribution system includes two optical sources for generating optical signals. A first optical source () is operable to generate a first optical signal having an operating frequency. A second optical source () is operable to generate a second optical signal having an operating frequency. A modulator () is operable to impress an RF modulation signal on a tapped portion of the first optical signal such that a modulated signal is generated. A first coupler () combines the modulated signal with a tapped portion of the second optical signal, thereby forming a combined signal having a difference frequency component. A control photodetector () is responsive to the combined signal to generate a tone signal. An offset locking circuit (), responsive to the tone signal, controls the operating frequency of the optical sources (and) such that the first optical signal and the second optical signal are frequency locked.

Photonic RF distribution system

A PIN electro-optical traveling wave modulator () including diffraction gratings () positioned at opposing sides of an optical waveguide () that act to change the propagation pattern of the waveguide (). The modulator () includes an N-type layer (), a P-type layer () and an intrinsic layer () acting as the waveguide (). A metal electrode () is in electrical contact with the N-type layer (), and a metal electrode () is in electrical contact with the P-type layer (). The electrodes () define an RF transmission line. An optical wave () propagates along the waveguide () and interacts with the gratings () which slow the optical wave () to match its speed to the speed of the RF wave in the transmission line. In one embodiment, the gratings () are 2-D gratings formed by vertical holes () in the waveguide ().

Slow wave optical waveguide for velocity matched semiconductor modulators

A coupled quantum well Mach-Zehnder modulator that employs a push-pull structure to reduce the modulation voltage. The Mach-Zehnder modulator includes a first arm having a first PIN semiconductor device and a second arm having a second PIN semiconductor device. The intrinsic layers of the PIN devices include a coupled quantum well structure to provide an opposite index of refraction change for different DC bias voltages. An RF signal used to modulate the light beam is applied to the two arms in phase and causes the index of refraction in the intrinsic layers of the two PIN devices to change in opposite directions so that a push-pull type drive is achieved without requiring 180&#xb0; out-of-phase RF drive signal.

In-phase RF drive of Mach-Zehnder modulator push-pull electrodes by using coupled quantum well optical active region

A three terminal edge illuminated epilayer waveguide phototransistor including a subcollector layer formed of an epitaxially grown quaternary semiconductor material, such as heavily doped InGaAsP. A collector region of undoped InGaAs is epitaxially grown on the subcollector layer. A base region, including a heavily doped InGaAs base layer and a very thin undoped InGaAs spacer layer, is epitaxially grown on the collector layer. An emitter region, including a doped InGaAsP layer, a doped InP layer, and a heavily doped InGaAs emitter contact layer, is epitaxially grown on the base layer. The various layers and regions are formed so as to define an edge-illuminated facet for receiving incident light.

Three terminal edge illuminated epilayer waveguide phototransistor

Mach-Zehnder modulator with index tuned multimode interference couplers comprising a substrate, an optical input waveguide on the substrate for receiving a light signal, and an input multimode interference coupler. The input multimode interference coupler splits the received light and propagates it down two separate waveguides. Also, the input multimode interference coupler contains electrodes that allow the index of refraction to be tuned. These waveguides contain phase shift regions so that the light signals can be combined at the output multimode interference coupler out of phase. This allows the modulation of the light signal. Also, the output multimode interference coupler contains electrodes that allow the index of refraction to be tuned. The modulated light signal is then outputted through an output waveguide. The tuning of the index of refraction for the input and output multimode interference couplers eliminates the sensitivity of the areas to variations in their geometry.

Mach-Zehnder modulator with individually optimized couplers for optical splitting at the input and optical combining at the output

A monolithically integrated heterojunction bipolar transistor optoelectronic transimpedance amplifier using the first transistor as an optical detector. An edge illuminated epilayer waveguide phototransistor is used as the light-detecting element. The phototransistor is used as an optical detector in which the incident light pulses are converted to electrical pulses and then amplified for further signal processing. The phototransistor is monolithically integrated on the same material substrate as the emitter follower amplifier so that the parasitics normally associated with receiver circuitry are minimized. By eliminating the parasitic impedances, the circuit can be used as a receiver in high bit rate optical communication systems.

Heterojunction bipolar transistor optoelectronic transimpedance amplifier using the first transistor as an optical detector

An edge illuminated epilayer waveguide phototransistor including a subcollector layer formed from an epitaxially grown quaternary semiconductor material, such as heavily doped InGaAsP. A collector region of undoped InGaAs is epitaxially grown on the subcollector layer. A base region of moderately doped InGaAs is epitaxially grown on the collector layer. An emitter region, including a doped InGaAsP layer, a doped InP layer, and a heavily doped InGaAs emitter contact layer, is epitaxially grown on the base layer. The various layers and regions are formed so as to define an edge-illuminated facet for receiving incident light. Also, the base does not have an ohmic contact so that the base thickness can be minimized. Finally, the base doping concentration is minimized so that the gain-bandwidth product can be maximized.

Two terminal edge illuminated epilayer waveguide phototransistor

A metal-semiconductor-metal photodetector (,) is provided including an optical waveguide (,) disposed on a substrate (,) and an array of metal-semiconductor-metal photodiodes (,) coupled to the optical waveguide (,). An absorber (,) is disposed between the photodiodes (,) and the optical waveguide (,) and a transmission line (,) is coupled to the photodiodes (,). Each of the photodiodes (,) includes an electrode (,) having a plurality of interdigitated electrode fingers (,) wherein a width of each finger (,) and a gap between adjacent fingers (,) tapers from one end of the electrode (,) to the other. Preferably the rate of tapering corresponds to an exponential rate of optical power decay through the photodiode (,). In this way, both the photocurrent density in the fingers (,) and the uniformity of the electric field underneath the electrodes (,) are optimized.

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Lakewood, CA, United States of America

David C Scott