Fiber Optic Sensors: An Overview

Abstract

Fiber optic sensor technology is explained in terms of theory and applications. Various components common to all fiber optic sensors are compared. Two classes of sensing devices are emphasized: amplitude-modu-lated sensors and phase-modulated sensors. Specific examples of amplitude-modulated devices-one a pressure sensor using an optical reflection technique and another an accelerometer using a microbend technique-are described. Four types of fiber optic interferometers used in phase-modulated sensors are discussed. The effect of the optical fiber jacket on the sensitivity of phase-modulated sensors is considered. A miniature pressure sensor and a highly sensitive fiber optic accelerometer, both employing phase modula-tion, are described.