Introduction to Optical Metrology

13	Fiber Optic- and MEM-Based Measurements

13.1  INTRODUCTION

During the last couple of decades, fiber optic devices have been developed to sense and measure displacement, strain, flow, pressure, rotation, electrical and magnetic fields, and host of other variables. They offer the advantage of small sizes and are highly cost effective and hence have found applications in a large number of areas. Though the basic principle of operation of many of the fiber optic devices is similar to those used in conventional measurement devices, the sensing portion could be drastically different.

Fiber optic devices are grouped under two categories: (1) extrinsic or hybrid and (2) intrinsic or all fiber. In the former, the measurand modifies the properties ...