Systematic comparison of commercial devices for temporal characterization of few-cycle laser pulses in the 500-1000 nm spectral range.

We compare multiple temporal pulse characterization techniques in three different pulse duration regimes from 15 fs to sub-5 fs, as there are no available standards yet for measuring such ultrashort pulses. To accomplish this, a versatile post-compression platform was developed, where the 100 fs near infrared pulses were post-compressed to the sub-two-cycle regime in a hybrid, three-stage configuration. After each stage, the duration of the compressed pulse was measured with the d-scan, TIPTOE and SRSI techniques and the retrieved temporal intensity profiles, spectrum and spectral phases were compared.

Sub-ps Laser Deposited Copper Films for Application in RF Guns.

Copper thin films are intended to serve as a cover layer of photocathodes that are deposited by ablating copper targets in a high vacuum by temporally clean 600 fs laser pulses at 248 nm. The extremely forward-peaked plume produced by the ultrashort UV pulses of high-energy contrast ensures fast film growth. The deposition rate, defined as peak thickness per number of pulses, rises from 0.

Carrier-envelope phase stable few-cycle laser system delivering more than 100 W, 1 mJ, sub-2-cycle pulses.

Two-stage multipass-cell compression of a fiber-chirped-pulse amplifier system to the few-cycle regime is presented. The output delivers a sub-2-cycle (5.8 fs), 107 W average power, 1.

Reflectivity and spectral shift from laser plasmas generated by high-contrast, high-intensity KrF laser pulses.

The energy and spectrum of the reflected 248 nm radiation are studied from solid targets up to 1.15 × 10 W cm intensity. The experiments used the 700 fs directly amplified pulses of the KrF system which was cleaned from prepulses with the new Fourier-filtering method providing 12 orders of magnitude temporal contrast.

High-contrast, high-brightness ultraviolet laser system.

In this paper, improved operation of a high-contrast, high-brightness ultraviolet laser system is described. The laser system is based on a conventional short-pulse dye/excimer design, modified to contain 3 KrF excimer short-pulse amplifiers and the recently developed nonlinear Fourier-filtering stage for contrast improvement. The final amplifier accepts a beam size of ~4x4 cm, producing 100 mJ energy of short-pulses using a two-beam interferometric multiplexing setup.

Improvement of the temporal and spatial contrast of the nonlinear Fourier-filter.

Recently a novel method called nonlinear Fourier-filtering was suggested for temporal and spatial cleaning of high-brightness laser pulses. In this paper experimental demonstration of the associated spatial filtering of this method and significant improvement of the temporal filtering feature are presented. The formerly found limit of ~10 for the temporal contrast improvement is identified as diffraction effects caused by the limited numerical aperture of imaging.

Plasma mirrors for short pulse KrF lasers.

It is demonstrated for the first time that plasma mirrors can be successfully applied for KrF laser systems. High reflectivity up to 70% is achieved by optimization of the beam quality on the plasma mirror. The modest spectral shift and the good reflected beam quality allow its applicability for high power laser systems for which a new arrangement is suggested.