Preface. Introduction. Refractive Index: Introduction. Measurement. Dispersion Relations for Refractive Index. Derivation of the Sellmeier Coefficients. Sellmeier Coefficients. Comparison of Refractive Indexes. References. Thermo-Optic Coefficients: Definition. Measurement. Dispersion Relations. Derivation of the Sellmeier Coefficients: Nonlinear Crystals. Other Oxide and Laser Crystals. Halide Crystals/Glasses. Semiconductors. Optical Fiber/Optical Glasses. References. Applications: Nonlinear Optical Laser Devices: Noncritically Phase-Matched Second Harmonic Generations. Noncritical Optical Parametric Oscillators. Sum Frequency Generation. Optical Fiber Communication Systems: Chromatic Dispersion and Zero-Dispersion Wavelength. Thermo-Optic Switch. Optical Fiber Temperature Sensor. Thermo-Optic Modulators. References. Future Technology. Subject Index.