Chapter 2 Basic Instrumentation for Optical Measurement 2.0. Introduction 2.1. Grating-Based Optical Spectrum Analyzers 2.1.1. General Specifications 2.1.2. Fundamentals of Diffraction Gratings 2.1.3. Basic OSA Configurations 2.2. Scanning FP Interferometer 2.2.1. Basic FPI Configuration and Transfer Function 2.2.2. Scanning FPI Spectrum Analyzer 2.2.3. Scanning FPI Basic Optical Configurations 2.2.4. Optical Spectrum Analyzer Using the Combination of Grating and FPI 2.3. Mach-Zehnder Interferometers 2.3.1. Transfer Matrix of a 2 Â 2 Optical Coupler