NONLINEAR OPTICAL PHENOMENA IN GLASS

The nonlinear optical properties of glass have recently become the focus of growing scientific and technological interest. Nonlinear properties include intensity-dependent refractive index, multiphoton absorption, second and third harmonic generation, stimulated Raman and Brillouin scattering, and associated phenomena such as self-focusing, self-phase modulation, optical phase conjugation, and optical bistability. We report on a large amount of work that reaches beyond simple glasses such as silica. Nonlinear optical phenomena have been investigated in materials ranging from oxide, halide, and chalcogenide glasses to glasses doped with semiconductor microcrystals, organic dyes, and metal particles and in forms varying from bulk materials to optical fibres and waveguides. We also discuss recently discovered photoinduced effects in glass fibres, which include second harmonic generation and the formation of refractive index gratings. The ability to tailor the nonlinear optical properties of glass has been utilised in such diverse applications as controlling beam breakup in high power lasers, demonstration of all-optical devices for switching and logic, ultra short-pulse generation, and ultra long distance soliton transmission.