Nonlinear Propagation of an Ultrashort Pulse Lasers in the Medium

Nonlinear Optics Phenomena Titanium doped Sapphire is the most widely used crystal for wavelengths tunable lasers. It combines the excellent thermal physical and optical properties of Sapphire with the broadest tunable range of any known material. In optics an ultrashort pulse of light is an electromagnetic pulse whose time duration is of the order of a picosecond or less. Such pulses have a broadband optical spectrum and can be created by mode-locked oscillators. They are commonly referred to as ultrafast events. Amplification of ultrashort pulses almost always requires the technique of chirped pulse amplification in order to avoid damage to the gain medium of the amplifier. Nonlinear optical behavior is not observed when light travels in free space. The nonlinearity resides in the medium through which the light travels rather than in the light itself. The interaction of light with light is therefore mediated by the nonlinear medium: the presence of an optical field modifies the properties of the medium which in turn causes another optical field or even the original field itself to be modified.