Browse Prior Art Database

Apparatus for Optical Characterization of Lightwave Waveguides

IP.com Disclosure Number: IPCOM000036741D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Fan, B: AUTHOR [+3]

Abstract

An apparatus for convenient, reproducible and reliable characterization of optical waveguides using fiber excitation and a pneumatically- driven prism coupler is disclosed.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 64% of the total text.

Page 1 of 1

Apparatus for Optical Characterization of Lightwave Waveguides

An apparatus for convenient, reproducible and reliable characterization of optical waveguides using fiber excitation and a pneumatically- driven prism coupler is disclosed.

A standard technique for experimentally determining the propagation constants of guided modes in thin-film optical waveguides is prism coupling [*]. A common problem encountered with the prism-coupling technique is the difficulty in obtaining reproducible results even with the same sample. This is because the prism is usually pressed against the waveguide substrate with a fine-threaded screw. The pressure applied onto the prism directly affects the substrate-prism gap and, thereby, the coupling efficiency. Such a mechanism is operator- sensitive, and in the worst instance can crack the sample if excessive pressure is applied.

These problems have been eliminated by an apparatus in which the prism is held by a non-rotatable fixture which, in turn, is fastened to a frictionless slide to assure only a linear motion. The fixture is pneumatically driven so that the pressure on the prism can be controlled and monitored. Coupling efficiency can be maintained to within 1% at a given applied pressure. The waveguide, coupling prism with its associated fixture and holder for input fiber are placed on a precision rotary table. The propagation constants of the guided waves are determined from the angle between the mode-lines and the normal-to- p...