It is well-known that the process of optical parametric amplification (OPA) can be sensitive to the phases of the incident waves. In OPA realized by three-wave mixing, injection of all three waves into the same mode with appropriate phase relationship results in amplification of the signal phase, with an associated deamplification of the signal energy. Prospects for the use of this technique in...

The wave equation describing an ultrashort, tightly focused laser pulse in vacuum is solved analytically. Plasma dispersive effects are also included. Based on exact short-pulse solutions, analytical expressions are obtained for the pulse-length evolution, the pulse centroid motion, and the group velocity. Approximate shortpulse solutions are obtained to arbitrary order in the parameter ly2pL ,...

I present a numerical package, written in MATLAB, which provides a simplified scripting interface for simulating a host of ultrashort pulse propagation phenomena. With the proliferation of ultrashort laser technologies, the demand for efficient and accurate simulations has grown significantly. Here I introduce a linear-operator-based formalism for nonlinear pulse propagation beyond the slowly-v...

1 HAWKINS, R. T. : ‘Generation of < 3 ps optical pulses by fibre compression of gain-switched InCaAsP DFB laser diode pulses’, Electron. Lett., 1990,26, pp. 292-294 2 TSKADA, ., IWATSUKI, ., and SARUWATARI, M.: ‘Picosecond laser diode pulse amplification up to 12 W by laser diode pumped erbium-doped fiber’, IEEE Photonics Technol. Lett., 1990, 2, pp. 122-124 3 CHUSSEAU, L., BOUCHON, D., O U V I...

In laser-plasma experiments, we observed that ion acceleration from the Coulomb explosion of the plasma channel bored by the laser is prevented when multiple plasma instabilities, such as filamentation and hosing, and nonlinear coherent structures (vortices or postsolitons) appear in the wake of an ultrashort laser pulse. The tailoring of the longitudinal plasma density ramp allows us to contro...

We investigate experimentally the role that the initial temporal profile of ultrashort laser pulses has on the self-focusing dynamics in the anomalous group-velocity dispersion (GVD) regime. We observe that pulse-splitting occurs for super-Gaussian pulses, but not for Gaussian pulses. The splitting does not occur for either pulse shape when the GVD is near-zero. These observations agree with pr...

We attempt to evaluate the applicability of the concept of the critical power for self-focusing, originally developed for intense quasi-continuous-wave (cw) beams, to the case of ultra-intense and ultrashort laser pulses propagating in air. Our results show that, unlike in the cw case, no particular value of peak pulse power can be viewed as a sharp demarcation line between linear and nonlinear...

We observe multiply frustrated tunneling ionization-induced dissociation of the argon dimers by intense linearly polarized ultrashort laser pulses. By measuring the kinetic energy release and angular distribution of the Coulomb explosion of up to eightfold ionized argon dimers, we can trace the recapture of up to two electrons to Rydberg states of the highly charged compound at the end of the l...