Lumileds Lighting U.s., LLC

Agilent Technologies, Inc.

Philips Lumileds Lighting Company LLC

Tun Sein Tan

Michael Ragan Krames

Fred A Kish, Jr

Daniel Alexander Steigerwald

Jonathan J Wierer, Jr

Pradeep Rajkomar

Paul Scott Martin

Douglas Michael Baney

William Ian McAlexander

Bogdan Szafraniec

Richard Paul Tella

Mohan Gurunathan

Doug Baney

A system and method for superheterodyne detection in accordance with the invention. The system comprises a first conversion unit for performing a first heterodyne operation on an optical input signal to generate an electrical IF signal. A second conversion unit is electrically or optically coupled to the first conversion unit. The second conversion unit performs a second heterodyne operation to generate an electrical output signal suitable for signal processing.

Method and system for superheterodyne detection of an optical input signal

A receiver and method for using the same to process optical signals is disclosed. The receiver includes an optical coupler and a polarization dependent beam splitter. The optical coupler combines an input signal and a local oscillator signal into a first combined signal. The optical coupler includes a polarization filter that operates on the local oscillator to provide a linearly polarized signal having a predetermined LO polarization direction.

Polarization diverse optical receiver using a polarization-dependent beam splitter

A method for designing semiconductor light emitting devices is disclosed wherein the side surfaces (surfaces not parallel to the epitaxial layers) are formed at preferred angles relative to vertical (normal to the plane of the light-emitting active layer) to improve light extraction efficiency and increase total light output efficiency. Device designs are chosen to improve efficiency without resorting to excessive active area-yield loss due to shaping. As such, these designs are suitable for low-cost, high-volume manufacturing of semiconductor light-emitting devices with improved characteristics.

Light extraction from a semiconductor light emitting device via chip shaping

In one embodiment, a method determines the spectral content of an optical signal. Specifically, the optical signal and an optical local oscillator (LO) signal are provided to inputs of an optical hybrid (e.g., an N&#xd7;N optical coupler where N is greater than two). The phase-diverse components from the optical hybrid are photodetected allowing for mixing of the optical signal and the optical local oscillator. Bandpass filtering is performed to eliminate or reduce relative intensity noise (RIN). The filtered signals are mixed with an electrical LO signal. A quadrature representation of a phase-diverse heterodyne signal is generated from signals from the mixing. The negative image and the positive image from the quadrature representation are separated. The spectral content of the optical signal is determined from the images.

Systems and methods for determining the spectral content of an optical signal

The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n&#x3e;1.8) superstrate.

III-nitride light-emitting device with increased light generating capability

A test structure supports simultaneous characterization of a two port optical component. The test structure includes an input port for receiving an input signal from an optical source, two test ports for connecting the test structure to a component under test, separate optical paths for supplying reflected and transmitted optical response signals from the component under test to separate receivers, and optical components for combining a first portion of the input signal with the reflected optical response signal before the first portion of the input signal and the reflected optical response signal are detected by a first receiver and for combining a second portion of the input signal with the optical response signal before the second signal and the optical response signal are detected by a second receiver. The optical component of the test structure may be connected by optical fibers or integrated into a single substrate.

Test structure for simultaneously characterizing two ports of an optical component using interferometer-based optical network analysis

A light-emitting diode (LED) and a method of making the device utilize a thick multi-layered epitaxial structure that increases the light extraction efficiency of the device. The LED is an aluminum-gallium-indium-nitride (AlGaInN)-based LED. The thick multi-layered epitaxial structure increases the light extraction efficiency of the device by increasing the amount of emitted light that escapes the device through the sides of the thick multi-layered epitaxial structure. The LED includes a substrate, a buffer layer, and the thick multi-layered epitaxial structure. In the preferred embodiment, the substrate is a sapphire substrate having a textured surface. The textured surface of the substrate randomized light impinges the textured surface, so that an increased amount of emitted light may escape the LED as output light. The multi-layered epitaxial structure includes an upper AlGaInN region, an active region, and a lower AlGaInN region. The upper and lower AlGaInN regions include multiple epitaxial layers of AlGaInN. The upper AlGaInN region is made of p-type AlGaInN epitaxial layers, while the lower AlGaInN region is made of n-type AlGaInN epitaxial layers and undoped epitaxial layers. The undoped epitaxial layers may be layers of AlGaInN or other AlGaInN-based material. The multi-layered epitaxial structure has an approximate thickness of 4 micrometers or greater. In one embodiment, the thickness of the multi-layered epitaxial structure is approximately 7 micrometers. In another embodiment, the thickness of the multi-layered epitaxial structure is approximately 15 micrometers.

Aluminum indium gallium nitride-based LED having thick epitaxial layer for improved light extraction

The invention is a method for designing semiconductor light emitting devices such that the side surfaces (surfaces not parallel to the epitaxial layers) are formed at preferred angles relative to vertical (normal to the plane of the light-emitting active layer) to improve light extraction efficiency and increase total light output efficiency. Device designs are chosen to improve efficiency without resorting to excessive active area-yield loss due to shaping. As such, these designs are suitable for low-cost, high-volume manufacturing of semiconductor light-emitting devices with improved characteristics.

LED having angled sides for increased side light extraction

The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

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Cupertino, CA, United States of America

Tun Sein Tan