Tun S Tan

US Patent:

6486499, Nov 26, 2002

Filed:

Dec 22, 1999

Appl. No.:

09/469657

Inventors:

Michael R Krames - Mt View CA
Daniel A. Steigerwald - Cupertino CA
Pradeep Rajkomar - San Jose CA
Tun S Tan - Los Altos Hills CA

Assignee:

LumiLeds Lighting U.S., LLC - San Jose CA

International Classification:

H01L 2715

US Classification:

257 81, 257103

Abstract:

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.

US Patent:

6521914, Feb 18, 2003

Filed:

Mar 29, 2002

Appl. No.:

10/112175

Inventors:

Michael R Krames - Mt View CA
Daniel A. Steigerwald - Cupertino CA
Pradeep Rajkomar - San Jose CA
Tun S Tan - Los Altos Hills CA

Assignee:

LumiLeds Lighting, U.S., LLC - San Jose CA

International Classification:

H01L 29267

US Classification:

257 81

Abstract:

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.

US Patent:

6570190, May 27, 2003

Filed:

Dec 6, 2000

Appl. No.:

09/732326

Inventors:

Michael R Krames - Mt View CA
Tun S Tan - Cupertino CA

Assignee:

Lumileds Lighting, U.S., LLC - San Jose CA

International Classification:

H01L 3300

US Classification:

257 94, 257 95, 257 98

Abstract:

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.

US Patent:

6649440, Nov 18, 2003

Filed:

Jul 17, 2000

Appl. No.:

09/617324

Inventors:

Michael Ragan Krames - Mountain View CA
Paul Scott Martin - Pleasanton CA
Tun Sein Tan - Cupertino CA

Assignee:

Lumileds Lighting U.S., LLC - San Jose CA

International Classification:

H01L 2100

US Classification:

438 47, 438964

Abstract:

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.

US Patent:

6750973, Jun 15, 2004

Filed:

Feb 20, 2002

Appl. No.:

10/081774

Inventors:

Tun Sein Tan - Palo Alto CA
Douglas M. Baney - Palo Alto CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

G01B 902

US Classification:

356477, 356 731

Abstract:

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.

US Patent:

6844571, Jan 18, 2005

Filed:

Feb 7, 2002

Appl. No.:

10/071507

Inventors:

Michael R Krames - Mt. View CA, US
Daniel A. Steigerwald - Cupertino CA, US
Pradeep Rajkomar - San Jose CA, US
Tun S Tan - Los Altos Hills CA, US

Assignee:

Lumileds Lighting U.S., LLC - San Jose CA

International Classification:

H01L 2715
H01L 3112
H01L 3300

US Classification:

257 81, 257 12, 257 13, 257 37, 257 38, 257 39, 257 98

Abstract:

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.

US Patent:

7265849, Sep 4, 2007

Filed:

Sep 25, 2003

Appl. No.:

10/670538

Inventors:

Mohan Gurunathan - Mountain View CA, US
William Ian McAlexander - Redwood City CA, US
Tun S. Tan - Los Altos Hills CA, US

Assignee:

Agilent Technologies, Inc. - Santa Clara CA

International Classification:

G01B 9/02

US Classification:

356484

Abstract:

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×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.

US Patent:

7280770, Oct 9, 2007

Filed:

May 18, 2004

Appl. No.:

10/848229

Inventors:

Tun S. Tan - Los Altos Hills CA, US
Doug Baney - Los Altos CA, US
William Ian McAlexander - Redwood City CA, US
Richard P. Tella - Sunnyvale CA, US

Assignee:

Agilent Technologies - Santa Clara CA

International Classification:

H04B 10/00

US Classification:

398205, 398207, 398212

Abstract:

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.