Handbook of Optical Metrology, 2nd Edition

16	Displacement
Akiko Hirai, Mariko Kajima, and Souichi Telada

CONTENTS

16.1    Introduction

16.2    Laser Interferometer

16.2.1    Homodyne Interferometer and Heterodyne Interferometer

16.2.2    Optical System of an Interferometer

16.2.3    Factors That Effect the Measurement Result and Uncertainty

16.2.3.1    Refractive Index of Air

16.2.3.2    Stability of the Dead Path

16.2.3.3    Unbalanced Optical Path Lengths and Thermal Change

16.2.3.4    Abbe Error

16.2.3.5    Cosine Error

16.2.3.6    Nonlinear Errors

16.2.4    Other Interferometers

16.3    Linear Encoders

16.3.1    Measurement Principle

16.3.1.1    Incremental Type and Absolute Type

16.3.1.2    Scale Mark Detection

16.3.2    Methods of Scale Mark Detection

16.3.2.1    Moiré ...