Resonant tunneling controlled by laser and constant electric fields

We develop the concept of scattering matrix and we use it to perform stable numerical calculations of resonant tunneling of electrons through a multiple potential barrier in a semiconductor heterostructure. Electrons move in two external nonperturbative electric fields: constant and oscillating in time. We apply our algorithm for different strengths and spatial configurations of the fields.Comment: 10 pages, 11 figure

Measurements of the indium hyperfine structure in an atmospheric-pressure flame by use of diode-laser-induced fluorescence

We report on what we believe is the first demonstration of laser-induced fluorescence (LIF) in flames by use of diode lasers. Indium atoms seeded into an atmospheric-pressure flame at trace concentrations are excited by a blue GaN laser operating near 410 nm. The laser is mounted in an external-cavity configuration, and the hyperfine spectrum of the 5(2)P(1/2) → 6(2)S(1/2) transition is captured at high resolution in single-wavelength sweeps lasting less than one tenth of a second. The research demonstrates the potential of diode-based LIF for practical diagnostics of high-temperature reactive flows

Micropattern gas detectors

An overview of Micropattern Gas Detectors is given. Recent progress of detector research, especially in the context of Micromegas and Gas Electron Multipliers, is discussed. A particular emphasis is put on the pixelized readout with a dedicated ASIC nameed Timepix, where new results with both gas amplification stages atop this chip are presented