The nonlinear reflectivity of semiconductor saturable absorber mirrors is investigated with ultrafast time-resolved and time-averaged reflectivity measurements. The relative contributions of absorption bleaching and induced absorption are studied as a function of fluence and wavelength. The impact of induced absorption on the stability of continuous-wave mode-locking is considered theoretically...

Idealized climate modeling studies often choose to neglect spatiotemporal variations in solar radiation, but doing so comes with an important decision about how to average solar radiation in space and time. Since both clear-sky and cloud albedo are increasing functions of the solar zenith angle, one can choose an absorptionweighted zenith angle that reproduces the spatialor time-mean absorbed s...

Two-color quantum-well infrared photodetectors ~QWIPs! that are based on electron transfer between coupled QWs suffer from the presence of the shorter wavelength peak at all bias voltages. We investigate this problem in such detectors with 50 or 200 Å AlGaAs barriers between the QW pair. We deduce the absorption coefficient a and photoconductive gain g of the detectors with 50 Å barriers using ...

• Measurements of Collision Induced Absorption by H 2 +CO near 2.4 µm. Good agreement with previous experimental determinations. Validation calculations. Using a 101 m absorption path-length cell, Fourier transform spectra mixtures have been recorded at room temperature in the region around This enables to quantify induced, collisions CO , central part fundamental band . These measurements, whi...

Up to a thirty-fold detectivity enhancement is achieved for an InAs quantum dot infrared photodetector (QDIP) by the excitation of surface plasma waves (SPWs) using a metal photonic crystal (MPC) integrated on top of the detector absorption region. The MPC is a 100 nm-thick gold film perforated with a 3.6 microm period square array of circular holes. A bare QDIP shows a bias-tunable broadband r...

Photoinduced absorption spectroscopy (PIAS) is used to probe the kinetics of oxidation 4-chlorophenol, 4CP, by P25 TiO2 with anodic bias or using a sacrificial electron acceptor and establishes first order for reaction h+ 4CP.