Impact of Simulation-Based Training on Radiation Exposure of Young Interventional Cardiologists.

Reducing radiation exposure during cardiovascular catheterization is of paramount importance to ensure patient and staff safety. Our study aimed to assess the transferability of acquired skills from virtual reality to the real world, including radioprotection measures during mentored simulation training (ST) in coronary angiography. A total of 10 cardiology residents were evaluated during real-life cases in the catheterization laboratory before (group A) and after mentored ST. The educational effect of mentored simulator training on real-life case performance was evaluated at 2 different time points: within the first week (group B) and after 12 weeks (group C). Compared with group A, the total dose area product (DAP) (µGy•m2) and total air kerma (mGy) were lower after ST: group A: 2,633 (1,723 to 3,617) versus group B: 1,618 (1,032 to 2,562), p <0.05 and 214 (136 to 297) versus 135 (84 to 222), p <0.05, respectively. Concerning operator radiation exposure (µSv), left finger dose: 1,090 (820 to 1,460) versus 635 (300 to 900), p = 0.028; left leg dose 80 (0 to 110) versus 0 (0 to 0), p = 0.027; left eye lens dose: 39 (24 to 69) versus 11 (8 to 20), p <0.0001; and chest dose outside the lead apron: 50 (34 to 88) versus 29 (21 to 50), p <0.003 were significantly lower in the group B than group A. A total of 12 weeks after ST, the total DAP and total air kerma remained stable along with operator exposure except left eye lens dose (µSv): group B: 11 (8 to 20) versus group C: 16 (12 to 27), p = 0.02. In addition, left eye lens dose, left wrist dose, and chest dose outside the lead apron were significantly correlated with total DAP (rs = 0.635, rs = 0.729, and rs = 0, 629, respectively) and total air kerma (rs = 0.488, rs = 0.514, and rs = 0.548, respectively) at 12 weeks. In conclusion, ST for coronary angiography may improve radioprotection learning and should be incorporated into training curricula.

Wave packet interferometry with attosecond precision and picometric structure.

Wave packet (WP) interferometry is applied to the vibrational WPs of the iodine molecule. Interference fringes of quantum waves weave highly regular space-time images called "quantum carpets." The structure of the carpet has picometre and femtosecond resolutions, and changes drastically depending on the amplitudes and phases of the vibrational eigenstates composing the WP. In this review, we focus on the situation where quantum carpets are created by two counter-propagating nuclear vibrational WPs. Such WPs can be prepared with either a single or double femtosecond (fs) laser pulse. In the single pulse scheme, the relevant situation appears around the half revival time. Similar situations can be generated with a pair of fs laser pulses whose relative phase is stabilized on the attosecond time scale. In the latter case we can design the quantum carpet by controlling the timing between the phase-locked pulses. We demonstrate this carpet design and visualize the designed carpets by the fs pump-probe measurements, tuning the probe wavelength to resolve the WP density-distribution along the internuclear axis with ~3 pm spatial resolution and ~100 fs temporal resolution.

Actively tailored spatiotemporal images of quantum interference on the picometer and femtosecond scales.

Interference fringes of quantum waves weave highly regular space-time images, which could be seen in various wave systems such as wave packets in atoms and molecules, Bose-Einstein condensates, and fermions in a box potential. We have experimentally designed and visualized spatiotemporal images of dynamical quantum interferences of two counterpropagating nuclear wave packets in the iodine molecule; the wave packets are generated with a pair of femtosecond laser pulses whose relative phase is locked within the attosecond time scale. The design of the image has picometer and femtosecond resolutions, and changes drastically as we change the relative phase of the laser pulses, providing a direct spatiotemporal control of quantum interferences.

Time-dependent photoionization of azulene: competition between ionization and relaxation in highly excited states.

Pump-probe photoionization has been used to map the relaxation processes taking place from highly vibrationally excited levels of the S(2) state of azulene, populated directly or via internal conversion from the S(4) state. Photoelectron spectra obtained by 1+2(') two-color time-resolved photoelectron imaging are invariant (apart from in intensity) to the pump-probe time delay and to the pump wavelength. This reveals a photoionization process which is driven by an unstable electronic state (e.g., doubly excited state) lying below the ionization potential. This state is postulated to be populated by a probe transition from S(2) and to rapidly relax via an Auger-like process onto highly vibrationally excited Rydberg states. This accounts for the time invariance of the photoelectron spectrum. The intensity of the photoelectron spectrum is proportional to the population in S(2). An exponential energy gap law is used to describe the internal conversion rate from S(2) to S(0). The vibronic coupling strength is found to be larger than 60+/-5 microeV.

Factorization of numbers with the temporal Talbot effect: optical implementation by a sequence of shaped ultrashort pulses.

We report on the successful operation of an analogue computer designed to factor numbers. Our device relies solely on the interference of classical light and brings together the field of ultrashort laser pulses with number theory. Indeed, the frequency component of the electric field corresponding to a sequence of appropriately shaped femtosecond pulses is determined by a Gauss sum which allows us to find the factors of a number.

Quantum state measurement using coherent transients.

We present the principle and experimental demonstration of time resolved quantum state holography. The quantum state of an excited state interacting with an ultrashort chirped laser pulse is measured during this interaction. This has been obtained by manipulating coherent transients created by the interaction of femtosecond shaped pulses and rubidium atoms.

Visualizing picometric quantum ripples of ultrafast wave-packet interference.

Interference fringes in vibrating molecules are a signature of quantum mechanics, but are often so short-lived and closely spaced that they elude visualization. We have experimentally visualized dynamical quantum interferences, which appear and disappear in less than 100 femtoseconds in the iodine molecule synchronously with the periodic crossing of two counterpropagating nuclear wave packets. The obtained images have picometer and femtosecond spatiotemporal resolution, representing a detailed picture of the quantum interference.

Femtosecond spectral electric field reconstruction using coherent transients.

We have implemented a new approach for measuring the time-dependent intensity and phase of ultrashort optical pulses. It is based on the interaction between shaped pulses and atoms, leading to coherent transients.

Realization of a time-domain Fresnel lens with coherent control.

Perturbative chirped pulse excitation leads to oscillations of the excited state amplitude. These coherent transients are governed by interferences between resonant and off-resonant contributions. Control mechanisms in both frequency and time domain are used to modify these dynamics. First, by applying a phase step in the spectrum, we manipulate the phase of the oscillations. By direct analogy with Fresnel zone lenses, we then conceive highly phase-amplitude modulated pulse shapes that slice destructive interferences out of the excitation time structure and enhance the final population.