Phase-matching-free pulse retrieval based on transient absorption in solids.

In this paper, we introduce a pulse characterization technique that is free of phase-matching constraints, exploiting transient absorption in solids as an ultrafast optical switch. Based on a pump-probe setup, this technique uses pump pulses of sufficient intensity to induce the switch, while the pulses to characterize are probing the transmissivity drop of the photoexcited material. This enables the characterization of low-intensity ultra-broadband pulses at the detection limit of the spectrometer and within the transparency range of the solid.

Evidence of depolarization and ellipticity of high harmonics driven by ultrashort bichromatic circularly polarized fields.

High harmonics generated by counter-rotating laser fields at the fundamental and second harmonic frequencies have raised important interest as a table-top source of circularly polarized ultrashort extreme-ultraviolet light. However, this emission has not yet been fully characterized: in particular it was assumed to be fully polarized, leading to an uncertainty on the effective harmonic ellipticity. Here we show, through simulations, that ultrashort driving fields and ultrafast medium ionization lead to a breaking of the dynamical symmetry of the interaction, and consequently to deviations from perfectly circular and fully polarized harmonics, already at the single-atom level.

2.5 TW, two-cycle IR laser pulses via frequency domain optical parametric amplification.

Broadband optical parametric amplification in the IR region has reached a new milestone through the use of a non-collinear Frequency domain Optical Parametric Amplification system. We report a laser source delivering 11.6 fs pulses with 30 mJ of energy at a central wavelength of 1.

Molecular frame photoemission by a comb of elliptical high-order harmonics: a sensitive probe of both photodynamics and harmonic complete polarization state.

Due to the intimate anisotropic interaction between an XUV light field and a molecule resulting in photoionization (PI), molecular frame photoelectron angular distributions (MFPADs) are most sensitive probes of both electronic/nuclear dynamics and the polarization state of the ionizing light field. Consequently, they encode the complex dipole matrix elements describing the dynamics of the PI transition, as well as the three normalized Stokes parameters s, s, s characterizing the complete polarization state of the light, operating as molecular polarimetry. The remarkable development of advanced light sources delivering attosecond XUV pulses opens the perspective to visualize the primary steps of photochemical dynamics in time-resolved studies, at the natural attosecond to few femtosecond time-scales of electron dynamics and fast nuclear motion.

Attosecond dynamics through a Fano resonance: Monitoring the birth of a photoelectron.

The dynamics of quantum systems are encoded in the amplitude and phase of wave packets. However, the rapidity of electron dynamics on the attosecond scale has precluded the complete characterization of electron wave packets in the time domain. Using spectrally resolved electron interferometry, we were able to measure the amplitude and phase of a photoelectron wave packet created through a Fano autoionizing resonance in helium.

Flexible attosecond beamline for high harmonic spectroscopy and XUV/near-IR pump probe experiments requiring long acquisition times.

We describe the versatile features of the attosecond beamline recently installed at CEA-Saclay on the PLFA kHz laser. It combines a fine and very complete set of diagnostics enabling high harmonic spectroscopy (HHS) through the advanced characterization of the amplitude, phase, and polarization of the harmonic emission. It also allows a variety of photo-ionization experiments using magnetic bottle and COLTRIMS (COLd Target Recoil Ion Momentum Microscopy) electron spectrometers that may be used simultaneously, thanks to a two-foci configuration.

Defining The Other Solitude: Urban family practice training.

The changing content of urban-based family practice needs to be redefined so that appropriate family medicine training programs can be planned to meet the primary care health needs of Canada's urban-based population. Although the core content of family practice is common to both rural and urban areas, each requires specific skills and attitudes dictated by differences in patient characteristics, disease incidence, physician expectations, and professional contexts. A challenge for the future is the development of both rural-based and urban-based streams of family medicine training that will unite rather than divide the profesiion.

The Use of the Cavity-Rim Cervical Cap in a Family Physician's Office.

This paper describes a retrospective study which looked at the effectiveness of the Prentif cavity-rim cervical cap, cap usage, cap-associated problems and acceptability for 95 women fitted with a cervical cap at a family physician's office. The pregnancy rate of this group was 12.28/100 years of exposure.

The Drug Attitudes Scale (DAS): its development and evaluation.

Five studies were conducted, employing three independent samples of high school students, leading to the development and assessment of the reliability and validity of a Drug Attitudes Scales. The results of these studies support the conclusions that this scale shows substantial reliability and validity, and promises considerable utility in drug treatment and education research. The Drug Attitudes Scale consists of 60 attitude items dealing with drugs and drug use, and is comprised of 10 six-item subscales referring to tranquilizers, barbiturates, heroin, opiates other than heroin, "speed," alcohol, cannabis, hallucinogens, tobacco, and general drug use.