Attosecond pulses are generally at the single-cycle limit. In a recent theoretical study, we found an exact solution for the fields of a focused laser for arbitrary spot size [1] and pulse duration [2]. For example, in comparison with monochrome fields, the inclusion of longer wavelengths reduces the fraction of laser energy in the focus from 86.5% to 72.7% in a single-cycle Ti:Sapphire laser pulse. Thus, unlike light with long pulse duration (many optical cycles), the transverse distribution of the field is found to depend on the longitudinal field profile.

These theoretical predictions, along with others pertaining to the generation of ultrashort pulses of x-rays or electrons [3] with ultra-intense laser light, will be tested with newly built laser at UNL that operates at a peak power of >100 TW, pulse duration of <30 fs, and repetition rate of 10 Hz To support the stringent demands of such a state-of-the-art laser system, a 5,000-sq-ft laboratory has recently been renovated to provide a high degree of stability in terms of temperature (< +/- 0.25 degree C), humidity (< 5%) and vibration. Details of the laser system and the various methods in which it will be used to produce significant fluxes of ultrashort duration radiation will be discussed.

1. S. Sepke and D. Umstadter, "Exact analytical solution for the vector electromagnetic field of Gaussian, flattened Gaussian, and annular Gaussian laser modes," Opt. Lett. 31, 1447 (2006).

2. S. Sepke and D. Umstadter, "Analytical solutions for the electromagnetic fields of tightly focused laser beams of arbitrary pulse length", Opt. Lett., (accepted).

3. S. Banerjee, S. Sepke, R. Shah, A. Valenzuela, and D. Umstadter, "Optical deflection and temporal characterization of an ultra-fast laser-produced electron beam", Phys. Rev. Lett. 95, 035004 (2005).