Dispersion group-velocity

Fig 1. (a) Phase (b) group velocity dispersion curves for aluminium. Circles show minimum dispersion points. Diamonds show excitation positions for transducer designed for X/d = 2.4 where d is the plate thickness. 

Valdmanis J A and Fork R L 1986 Design considerations for a femtosecond pulse laser balancing self phase modulation, group velocity dispersion, saturable absorption, and saturable gain IEEE J. Quantum. Electron. 22 112-18... 

Nonlinear dispersion becomes relevant at sufficient pulse powers. In some fibre stmctures tire interiDlay between tire nonlinear dispersion and tire group velocity dispersion can be used to produce non-dispersive waves called solitons. Solitons, altliough beyond tire scope of tliis treatment, may revolutionize tire communication systems of tire future. A full treatment of soliton tlieory can be found in [4, 261. 

A 0.2-mm thick hexadecane layer was placed on the oxazine solution. The vibrational coherence at the hexadecane/solution interface was pump-probed in a similar manner [27]. The light pulses traveled in the hexadecane layer and experienced group velocity dispersion before arriving at the interface. This undesired dispersion... 

Rigorous treatment of the self-action problem needs the transformation of Eq.(2.1), (2.5) into a system of integro-differential equations. However, if just some orders of group velocity dispersion and nonlinearity are taken into account, an approximate approach can be used based on differential equations solution. When dealing with the ID-i-T problem of optical pulse propagation in a dielectric waveguide, one comes to the wave equation with up to the third order GVD terms taken into account ... 

Consider now how the solution obtained in the quasi-static approximation changes if the second-order group velocity dispersion is taken into account. It is seen from Fig. 29 that in a nonlinear waveguide of the structure A with the MD and the SS effects is first observed that spatial and temporal parameters of the field vary similarly to the case of the quasi-static approximation. Then, at a given power, spatiotemporal distribution varies depending on the value and sign of the dispersion coefficient 2- The pulse duration decreases in the case of anomalous GVD (k2 < 0) and increases in the case of normal GVD ( 2 > 0). 

The measured data was corrected for group velocity dispersion by comparison with white light generated in water under the same configuration, yielding in the end a two dimensional array of the fluorescence intensity as a function of frequency and time. Singular value decomposition and deconvolution of the obtained decays was used to reconstruct the spectral decay which would correspond to delta pulse excitation. S(t) was calculated from this processed data. 

The beam was passed through a pulse picker (4). In order to compensate pulse broadening ( chirp ) introduced by the pulse picker and to precompensate that caused by other bulky optics (lenses, polarizers etc.), the beam was passed through a group velocity dispersion compensation line (5), consisting of a pair of Brewster prisms and a mirror [20], The temporal width of the pump and probe pulses was checked with a fringe-resolved... 

This was first achieved by the Teramobile system [14]. The laser itself is based on the chirped pulse amplification (CPA) technique [33,34], with a Ti Sapphire oscillator and a Nd YAG pumped Ti Sapphire amplification chain. It provides 350 mJ pulses with 70 fs duration resulting in a peak power of 5 TW at a wavelength around 800 nm, with a repetition rate of 10 Hz. Its integration in the reduced space of the mobile laboratory required a particularly compact design (Fig. 14.6). The classical compressor set-up has been improved into a chirp generator to pre-compensate the group velocity dispersion (GVD) in air. Combined with an adjustable focus, this permits to... 

---