Clark-MXR (United States)

Laser plasma interaction reveals harmonic divergence <4 degrees and increasing with defocus. Circular polarization was found to cause a change in the angle of emission, which may be beneficial in efficient isolated attosecond pulse production.

Self-similar propagation of ultrashort, parabolic pulses in a laser resonator is observed theoretically and experimentally. This constitutes a new type of pulse shaping in mode-locked lasers: in contrast to the well-known static (solitonlike) and breathing (dispersion-managed soliton) pulse evolutions, asymptotic solutions to the nonlinear wave equation that governs pulse propagation in most of the laser cavity are observed. Stable self-similar pulses exist with energies much greater than can be tolerated in solitonlike pulse shaping, and this has implications for practical lasers.

Conventional laser machining is based on continuous-wave or long-pulse lasers. With these lasers, thermal diffusion limits the accuracy and the reproducibility of the machining process. Laser-matter interaction is fundamentally different in the ultrafast (femtosecond) regime. This discovery has opened the way for generalized fine laser micromachining.

High resolution (≈1000 pixels), rapidly updatable fs laser pulse shaping permits a terabit per second communications architecture and quantum control.