Arrangements for reducing wavelength sensitivity in prism-coupled SOI-based optical systems

US6917730B2 · kind B2 · utility

Assignee

• SiOptical, Inc. · US

Inventors

• Margaret Ghiron · Allentown, US
• Prakash Gothoskar · Allentown, US
• Robert Keith Montgomery · Easton, US
• Vipulkumar Patel · Emmaus, US
• Soham Pathak · Allentown, US
• Kalpendu Shastri · Orefield, US
• Katherine A. Yanushefski · Emmaus, US

Key dates

• Filing date: Apr 28, 2004
• Grant date: Jul 12, 2005
• Expiry date: Apr 28, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B26/0833
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical coupling system for use with multiple wavelength optical signals provides improved coupling efficiency between a free-space optical beam and a relatively thin, surface layer of an SOI structure (“SOI layer”), allowing for sufficient coupling efficiency (greater than 50%) over a predetermined wavelength range. An evanescent coupling layer, disposed between a coupling prism and an SOI layer, is particularly configured to improve the coupling efficiency. In one embodiment, the thickness of the evanescent layer is reduced below an optimum value for a single wavelength, the reduced thickness improving coupling efficiency over a predetermined wavelength range around a defined center wavelength. Alternatively, a tapered thickness evanescent coupling layer may be used to improve coupling efficiency (or a combination of reduced thickness and tapered configuration). Optical beam steering can be combined with a modified evanescent coupling layer to control the input beam launch angle and further improve coupling efficiency.