Two-photon absorption (2PA) spectra with pairs of extremely nondegenerate photons are measured in several direct-gap semiconductors (GaAs, CdTe, ZnO, ZnS and ZnSe) using picosecond or femtosecond pulses. In ZnSe, using photons with a ratio of energies of ~12, we obtain a 270-fold enhancement of 2PA when comparing to the corresponding degenerate 2PA coefficient at the average photon energy (ηω1 ...

Magneto-transmission measurements were carried out on a series of ZnMnSe/ZnBeSe quantum wells (QWs) in order to determine the band o!set of ZnBeSe relative to ZnSe. We observed strong transitions from the ground state of the valence band to that of the conduction band in this system. The transition energy was observed to systematically increase with increasing Be concentration in the ZnBeSe bar...

0030-4018/$ see front matter 2010 Elsevier B.V. A doi:10.1016/j.optcom.2010.01.053 * Corresponding author. E-mail addresses: [email protected] (G.R. Kumar), sh (S. Mahamuni). 1 Present address: K.J. Somaiya College of Sc. & Comm 077, India. The nonresonant third order nonlinear optical properties of three different sized Mn-doped ZnSe quantum dots (QDs) are investigated. The nonlinear absorption ...

High-brightness blue and green light-emitting diodes ~LEDs! based on II–VI double heterostructures ~DHs! have been successfully grown by molecular-beam epitaxy ~MBE! on ~100! ZnSe substrates. These LED structures consist of a 500–1000 Å thick active region of undoped blue-emitting Zn0.9Cd0.1Se/ZnSe multiple quantum wells or a green-emitting ZnTe0.1Se0.9 single quantum well sandwiched between a ...

The scattering effects in the infrared (IR) spectra of single, isolated bread yeast cells (Saccharomyces cerevisiae) on a ZnSe substrate and in metal microchannels have been probed by Fourier transform infrared imaging microspectroscopy. Absolute extinction [(3.4±0.6)×10(-7) cm(2) at 3178 cm(-1)], scattering, and absorption cross sections for a single yeast cell and a vibrational absorption spe...

This paper reports the first derived thermo-optical properties for vacuum deposited infrared thin films embedded in multilayers. These properties were extracted from the temperature-dependence of manufactured narrow bandpass filters across the 4-17 µm mid-infrared wavelength region. Using a repository of spaceflight multi-cavity bandpass filters, the thermo-optical expansion coefficients of PbT...

Multilayered Zn–Se–Te structures grown by migration enhanced epitaxy are studied by temperatureand excitation-dependent photoluminescence (PL) as well as magneto-PL. The PL consists of two bands: a blue band, overlaid with band edge sharp lines, dominant at low temperatures and high excitation, and a green band, which appears at elevated temperature and low excitation. Upon varying excitation i...

We demonstrate efficient amplification of few-optical-cycle mid-IR pulses in single-pass continuously pumped laser amplifiers based on polycrystalline Cr(2+):ZnS and Cr(2+):ZnSe. The 1.7 W output of a Kerr-lens mode-locked master oscillator at 2.4 µm central wavelength, 79 MHz repetition rate was amplified to 7.1 W and 2.7 W in Cr(2+):ZnS and Cr(2+):ZnSe, respectively. High peak power of the in...

The high fractional open area of metal thin film coatings, with two dimensional, hexagonally ordered, close packed arrays of holes, makes them of interest for the incorporation of plasmonic effects into a variety of optical devices. Gold films with hexagonal patterns of circular holes have been created on ZnSe infrared windows. The films have 2.50 μm diameter holes and a hexagonal lattice param...

We report the growth of ZnSe nanowires and nanoneedles using molecular beam epitaxy (MBE). Different growth regimes were found, depending on growth temperature and the Zn–Se flux ratio. By employing a combined MBE growth of nanowires and nanoneedles without any postprocessing of the sample, we achieved an efficient suppression of stacking fault defects. This is confirmed by transmission electro...