Department of Physics Colloquium
Title: Soft X-ray shines on the new attosecond horizon through the water window
Abstract: High power, femtosecond Ti:Sapphire lasers have been the workhorse for the first generation attosecond light sources for the last 15 years. The spectral range of isolated attosecond pulses with sufficient photon flux for time-resolved experiments has been limited to extreme ultraviolet (10 to 124 eV). The center wavelength of Ti:Sapphire lasers is 800 nm. It was demonstrated in 2001 by our group that the cutoff photon energy of the high harmonic spectrum can be extended by increasing the center wavelength of the driving lasers. In recent years, mJ level, two-cycle, carrier-envelope phase stabilized lasers at 1.6 to 2.1 micron have been developed. By driving high-order harmonic generation with an Optical Parametric Chirped Pulse Amplifier at 1.7 micron and implementing polarization gating, isolated x-ray pulses as short as 53 as with photon energy extending to more than 400 eV were produced and characterized in our laboratory. Attosecond water window x-rays will play an important role in the emerging field of attochemistry and petahertz photonics.
**Refreshments will be served at 2:30 p.m. (BEFORE the seminar) in room ARC 233