Mortgage life insurance: a rationale for a time limit in switching rights

I examine competition in the sector of mortgage life insurance, in particular the periodic switching right (PSR), by which the borrower can change his insurer once every period (say, every year). The PSR is likely to have pro competitive effects (lower premium), but by the same move, to lead to excessive segmentation. The main theoretical prediction of the PSR is that, in equilibrium, everyone will pay every year a premium reflecting his current risk, meaning that the risk of future risk evolution is not covered. This destruction of insurance is appreciated negatively by consumers. The trade-off is between, on the one hand, a lower price for insurance, and on the other hand, a lower quality of insurance. I simulate the cost of the PSR and find about 5–15 % of the total insurance cost. This order of magnitude is slightly smaller than the benefit one can expect from increased competition. All in all, a switching right limited in time would bring the benefits of competition and avoid most of the cost of segmentation.     

Conversion of high-power 15-fs visible pulses to the mid infrared

We measure the efficiency of converting high-power 15-fs 0.8-mum pulses to the mid infrared in GaAs and GaSe as well as the pulse duration and the spectrum of the infrared radiation that is produced. Free-carrier production limits the conversion efficiency in GaAs to approximately 5x10(-7) , allowing us to produce 2.5-pJ, 30-fs pulses spanning the spectral range from 6 to 14 mum . In GaSe we obtain, in a moderately saturated regime, a conversion efficiency of 7.5x10(-5) , limited by two-photon absorption, allowing us to produce pulses of 100-fs duration containing 10 nJ of energy.     

X-ray spectroscopy measurements of laser compressed,argon filled shells

Argon X-ray lines have been used in the past to diagnose laser-compressed targets. We extend such measurements to: (a) very high densities (ρ ≈ 9 gcm^-3) obtained when imploding small shells with short laser pulses, and (b) lower densities but higher πR values (≈4 mg cm^-2) obtained with large DT-Ar filled shells, imploded with long laser pulses. The 24-beam OMEGA laser has been used with 4–5 TW, 100 ps pulses in (a), and 1.5–2 TW, 1 ns pulses in (b).     

Proprietes electriques des phases de basse temperature M1, T et M2 dans VO2 dope au chrome et a l'aluminium

The electrical conductivity and thermopower have been measured on Cr and Al doped VO₂ single crystals. The insulating M₁, T and M₂ phases have a similar behaviour with an activation energy E_a ?0.40 eV. The conductivity halves abruptly at the T→M₂ transition but no discontinuity is observed for the thermopower. The ansiotropy of the thermopower may be due to the anisotropic mobility of the holes in the lower quasi one dimensional Hubbard band.     

Phase control of rotational wave packets and quantum information

Lasers can create rotational wave packets in gas-phase molecules which periodically revive as field-free, aligned distributions. We control the wave packet evolution with relatively weak laser pulses at fractional revivals which modify the phase between wave packet components. We demonstrate two phase control effects in oxygen: coherently switching revivals off and on, and doubling the revival frequency. When viewed as a quantum logic system, these effects correspond to a Hadamard and a T operation.     

Method for single-shot measurement of the carrier envelope phase of a few-cycle laser pulse

The interference between different harmonics of a few-cycle optical pulse in the region of the spectral overlap is sensitive to the phase of the optical carrier inside the pulse envelope. Near-surface third-harmonic generation from Si(001) combined with second-harmonic generation in a 10-mum -thick beta-barium borate crystal produces sufficiently strong harmonic emission for single-shot measurement. We propose using this technique to measure the carrier envelope phase of high-energy 5-fs pulses.     

Single-mode transmission in two-dimensional macroporous silicon photonic crystal waveguides

We report the infrared operation of a two-dimensional photonic crystal waveguide fabricated in silicon. Measurements of the transmission spectrum reveal a large transmission bandwidth within the 3.1-5.5-mum bulk-crystal photonic bandgap and a rich resonance structure. The calculated transmission spectrum for this structure is in good agreement with the measured spectrum and predicts a 10% single-mode bandwidth for the waveguide.     

Toward soliton emission in asymmetric GaAs/AlGaAs multiple-quantum-well waveguide structures below the half-bandgap

We report what is to our knowledge the first experimental evidence of nonlinear beam displacement in a strip-loaded GaAs/AlGaAs multiple-quantum-well waveguide with an asymmetric, nonlinear cladding. An intensity-dependent spatial displacement of ~2 mum was observed for the guided mode at a wavelength of 1.55 mum. Numerical simulations that correspond to the experiment are also presented. The device has the potential of providing a soliton-emission-based, ultrafast all-optical switch.     

High harmonic generation and the role of atomic orbital wave functions

High harmonic spectra were recorded from different rare-gas atoms under identical experimental conditions. It is shown that although each atom's spectrum is different, the differences are due almost entirely to the orbital influence in the recombination step. The amplitude of the continuum electron wave packet versus kinetic energy is derived from these data and is shown to be largely independent of the atom, in agreement with models of tunnel ionization. We compare the measurements with calculations in both the length gauge and the velocity gauge and show that the two gauges imply a different de Broglie wavelength.     

Attosecond strobing of two-surface population dynamics in dissociating H2+

Using H2+ and D2+, we observe two-surface population dynamics by measuring the kinetic energy of the correlated ions that are created when H2+ (D2+) ionize in short (40-140 fs) and intense (10(14) W/cm2) infrared laser pulses. Experimentally, we find a modulation of the kinetic energy spectrum of the correlated fragments. The spectral progression arises from a hitherto unexpected spatial modulation on the excited state population, revealed by Coulomb explosion. By solving the two-level time-dependent Schr?dinger equation, we show that an interference between the net-two-photon and the one-photon transition creates localized electrons which subsequently ionize.