WILLIAM THOMAS
Emergency Medical Service in Cottonwood Heights, UT

4354736, Oct 19, 1982

Jun 18, 1980

6/160698

Mokhtar S. Maklad - Milford CT
Francis I. Akers - Roanoke VA
William L. Thomas - Midvale UT

International Telephone and Telegraph Corporation - New York NY

G02B 5172

350 9632

The stress-induced birefringent single mode optical fiber includes an optical core having a high refractive index and a high thermal expansion coefficient. An arrangement formed from an optical material having a low refractive index and a low thermal expansion coefficient is disposed to engage the outer surface of the core tangentially at opposite ends of a diameter of the core to establish a stress therein. Air encompasses the remainder of the outer surface of the core to provide a light guiding cladding for the core and, hence, the fiber itself. The arrangement to establish the stress may include a pair of flat plates engaging the outer surface of the core tangentially which are entrapped in a circular tube which is concentric with the core such that air is entrapped between the plates and the circular tube to provide the light guiding cladding. Alternatively, an elliptical tube is provided to engage the outer surface of the core at the minor axis of the elliptical tube to provide the desired stress in the fiber. In this case air is enclosed in the elliptical tube to provide the light guiding cladding.