Tunable sub-20 fs pulses from a 500 kHz OPCPA with 15 W average power based on an all-ytterbium laser

An optical parametric chirped pulse amplifier fully based on Yb lasers at 500 kHz is described. Passive optical-synchronization is achieved between a fiber laser-pumped white-light and a 515 nm pump produced with a 200 W picosecond Yb:YAG InnoSlab amplifier. An output power up to 19.7 W with long-term stability of 0.3% is demonstrated for wavelength tunable pulses between 680 nm and 900 nm and spectral stability of 0.2%; 16.5 W can be achieved with a bandwidth supporting 5.4 fs pulses. We demonstrate compression of 30 microjoule pulses to sub-20 fs duration with a prism compressor, suitable for high harmonic generation.Comment: 4 pages, 4 figure

Temporal and spatial effects inside a compact and CEP stabilized, few-cycle OPCPA system at high repetition rates

We present a compact and ultra-stable few-cycle OPCPA system. In two non-collinear parametric amplification stages pulse energies up to 17 mu J at 200 kHz repetition rate are obtained. Recompression of the broadband pulses down to 6.3 fs is performed with chirped mirrors leading to peak powers above 800 MW. The parametric amplification processes were studied in detail employing (2 + 1) dimensional numerical simulations and compared to experimental observations in terms of spectral shapes, pulse energy, spatial effects as well as delay dependent nonlinear mixing products. This gives new insights into the parametric process and design guidelines for high repetition rate OPCPA systems. (C) 2013 Optical Society of Americ

Carrier-envelope phase dependent high-order harmonic generation with a high-repetition rate OPCPA-system

We study high-order harmonic generation with a high-repetition rate (200 kHz), few-cycle, driving laser, based on optical parametric chirped pulse amplification. The system delivers carrier-envelope phase stable, 8 fs, 10 μJ pulses at a central wavelength of 890 nm. High-order harmonics, generated in a high-pressure Ar gas jet, exhibit a strong CEP-dependence over a large spectral range owing to excellent stability of the driving laser pulses. This range can be divided into three spectral regions with distinct CEP influence. The observed spectral interference structures are explained by an analytical model based upon multiple pulse interferences.Marie Curie Research Training Network ATTOFELEuropean Research CouncilKnut and Alice Wallenberg foundationSwedish Foundation for Strategic ResearchSwedish Research Counci

Beeinflusst Rauchen Rückenschmerzen und spinale Operationsergebnisse?

For a long time, orthopaedic surgeons have suspected an influence of smoking on several musculoskeletal diseases. The aim of this review is to discuss the influence of smoking on low back pain (LBP) and the outcome of spinal surgery. LBP is a highly prevalent disease and plays an important economic role, as it is associated with high direct and indirect health-care costs. In order to be successful in prevention, risk factors for LBP must be identified

Few-cycle and phase stable OPCPA systems with high repetition rate

We present different approaches for high repetition rate, few-cycle pulse generation with μJ-level energy from compact OPCPA systems. The sources are based on octave spanning Ti:Sa oscillators with all-optical synchronization to state-of-the-art Ytterbium based amplifiers

CEP dependent high-order harmonic generation at 200 khz repetition rate

We present the carrier-envelope phase dependent high-order harmonic generation in argon at 200 kHz repetition rate using ultra-short laser pulses from an optical parametric chirped pulse amplifier