Star coupler for optical fibers

US4846543A · kind A · utility

Assignee

• Kaptron, Inc. · US

Inventors

• Narinder S. Kapany · Woodside, US
• Fred C. Unterleitner · Palo Alto, US

Key dates

• Filing date: Dec 18, 1987
• Grant date: Jul 11, 1989
• Expiry date: Dec 18, 2007

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S359/90
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A star coupler/monitor comprises a beam splitter (25) and at least one imaging element (30) oriented relative to first, second, and third spatially discrete regions (35a-c) as follows. A minor portion of the light emanating from any given point in the first region (35a) is imaged at a corresponding point in the second region (35b). A major portion of the light emanating from the given point is imaged at a corresponding point in the third region (35c). The ends of N input fibers in an input bundle (12) are registered in an array in the first region (35a). The ends of N monitor fibers in a monitor bundle (15) are registered fiber-by-fiber at optically conjugate locations in the second region (35b) so that a minor portion of the light emanating from any one of the input fibers is imaged at the corresponding monitor fiber end. An integrating element (17) such as a rod is disposed in the third region (35c). The method achieves registration simply and virtually automatically by forming both bundles in the first instance from a single bundle. The method comprises the steps of providing a plurality of fibers (76), reducing the cladding thickness over corresponding intermediate portions (77…