Light-emitting diode incorporating gradient index element

US7102177B2 · kind B2 · utility

Assignee

• Avago Technologies ECBU IP (Singapore) Pte. Ltd. · SG

Inventors

• Kee Siang Goh · Bukit Mertajam, MY
• Yee Loong Chin · Batu Gajah, MY
• Boon K. Lee · Leander, US
• Cheng Why Tan · Bukit Mertajam, MY

Key dates

• Filing date: Aug 26, 2003
• Grant date: Sep 5, 2006
• Expiry date: Oct 24, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/855

Abstract

The light-emitting device includes a light source and a gradient index (GRIN) element. The GRIN element has a cylindrical refractive index profile in which the refractive index varies radially and is substantially constant axially. The GRIN element includes a first end surface opposite a second end surface and is characterized by a length-to-pitch ratio. The GRIN element is arranged with the first end surface adjacent the light source to receive light from the light source, and emits the light from the second end surface in a radiation pattern dependent on the length-to-pitch ratio. Since the radiation pattern depends on the length-to-pitch ratio of the GRIN element, LEDs with different radiation patterns can be made simply by using GRIN elements of appropriate lengths.