We have investigated the fundamental mechanism underlying the hydrogen-induced exfoliation of silicon, using a combination of spectroscopic and microscopic techniques. We have studied the evolution of the internal defect structure as a function of implanted hydrogen concentration and annealing temperature and found that the mechanism consists of a number of essential components in which hydrogen plays a key role. Specifically, we show that the chemical action of hydrogen leads to the formation of (100) and (111) internal surfaces above 400 °C via agglomeration of the initial defect structure. In addition, molecular hydrogen is evolved between 200 and 400 °C and subsequently traps in the microvoids bounded by the internal surfaces, resulting in the build-up of internal pressure. This, in turn, leads to the observed “blistering” of unconstrained silicon samples, or complete layer transfer for silicon wafers joined to a supporting (handle) wafer which acts as a mechanical “stiffener.”

High-resolution vibrational spectroscopy of fullerene thin films is achieved by sum-frequency generation and infrared absorption. The $A_g\left(2\right)$ mode of ${\mathrm{C}}_{60}$ gains strong infrared activity when the molecule is adsorbed on Ag(111). K doping allows us to demonstrate the process of adsorbate/substrate dynamical charge transfer, by showing, for the first time, the quenching of the mode softening and infrared activity upon tuning of the admolecule electronic properties. These observations enable the quantitative evaluation of the coupling strength of the $A_g\left(2\right)$ vibration to the $t_{1u}$ orbital of ${\mathrm{C}}_{60}$.

We present a procedure to completely determine the complex modular values of arbitrary observables of pre- and postselected ensembles, which works experimentally for all measurement strengths and all postselected states. This procedure allows us to discuss the physics of modular and weak values in interferometric experiments involving a qubit meter. We determine both the modulus and the argument of the modular value for any measurement strength in a single step, by simultaneously controlling the visibility and the phase in a quantum eraser interference experiment. Modular and weak values are closely related. Using entangled qubits for the probed and meter systems, we show that the phase of the modular and weak values has a topological origin. This phase is completely defined by the intrinsic physical properties of the probed system and its time evolution. The physical significance of this phase can thus be used to evaluate the quantumness of weak values.

We report on the performances of the mode locking of a flash-lamp-pumped Nd:YAG laser using a frequency-doubling nonlinear mirror combined with a two-photon absorber. Pulse lengths from 12 to 8 ps are generated. We show that the flat shape of the pulse-train envelope generated by the oscillator is adapted for the synchronous pumping of optical parametric oscillators and we demonstrate the efficient generation of an infrared beam tunable from 3800 to $\text{1100\hspace{0.5em}}{\mathrm{cm}}^{\text{−1}}$ with bandwidth of $\text{2\hspace{0.5em}}{\mathrm{cm}}^{\text{−1}}$ in one single conversion stage in ${\mathrm{LiNbO}}_{\mathrm{3}}$ or ${\mathrm{AgGaS}}_{\mathrm{2}}.$ The “all-solid-state” laser system enables surface sum-frequency generation spectroscopy to be performed with high sensitivity and high resolution.