Simultaneous compression, characterization and phase stabilization of GW-level 1.4 cycle VIS-NIR femtosecond pulses using a single dispersion-scan setup.

We have temporally characterized, dispersion compensated and carrier-envelope phase stabilized 1.4-cycle pulses (3.2 fs) with 160 µJ of energy at 722 nm using a minimal and convenient dispersion-scan setup.

Ultrabroadband efficient intracavity XUV output coupler.

We report an efficient intracavity XUV output coupler based on an anti-reflection-coated grazing incidence plate (GIP). Conceptually, GIP is an extension of a Brewster plate, affording low loss of the circulating fundamental light and serving as a highly efficient, extremely broadband output coupler for XUV. Due to the grazing incidence geometry, the short wavelength reflectivity can be extended to the keV range.

Power scaling of a high-repetition-rate enhancement cavity.

A passive optical resonator is used to enhance the power of a pulsed 78 MHz repetition rate Yb laser providing 200 fs pulses. We find limitations relating to the achievable time-averaged and peak power, which we distinguish by varying the duration of the input pulses. An intracavity average power of 18 kW is generated with close to Fourier-limited pulses of 10 W average power.

Accurate retrieval of target structures and laser parameters of few-cycle pulses from photoelectron momentum spectra.

We illustrate a new method of analyzing three-dimensional momentum images of high-energy photoelectrons generated by intense phase-stabilized few-cycle laser pulses. Using photoelectron momentum spectra that were obtained by velocity-map imaging of above-threshold ionization of xenon and argon targets, we show that the absolute carrier-envelope phase, the laser peak intensity, and pulse duration can be accurately determined simultaneously (with an error of a few percent). We also show that the target structure, in the form of electron-target ion elastic differential cross sections, can be retrieved over a range of energies.

High harmonic frequency combs for high resolution spectroscopy.

We generated a series of harmonics in a xenon gas jet inside a cavity seeded by pulses from a Ti:sapphire mode-locked laser with a repetition rate of 10.8 MHz. Harmonics up to 19th order at 43 nm were observed with plateau harmonics at the microW power level.