Optical Fiber Sensors

15Optical Fiber Humidity Sensors

Muhammad Yusof Mohd Noor, Gang-Ding Peng, and Ginu Rajan

Contents

15.1 Introduction

15.2 Humidity Measurement Parameters

15.2.1 Electronic versus Optical Fiber Humidity Sensor

15.3 Classification of Fiber-Optic Humidity Sensor

15.3.1 Hygroscopic Material–Coated Sensors

15.3.1.1 Evanescent Wave

15.3.1.2 In-Fiber Grating

15.3.1.3 Interferometry

15.3.1.4 Spectroscopic

15.3.2 Noncoated Optical Fiber Humidity Sensors

15.3.2.1 Adsorption of Water Molecule

15.3.2.2 Edlén Theorem and Air Index of Refraction Principle

15.3.2.3 Beer–Lambert Law

15.3.2.4 Polymer Fiber

15.3.2.5 Recent Development of Microstructured Fiber Humidity Sensor

15.4 Application Areas

15.5 Summary

References

15.1 Introduction

Optical fiber sensors ...