Power absorption is calculated for electron cyclotron resonance heating (ECRH) in the H-1 heliac device by using a ray tracing numerical code. The three-dimensional magnetic field structure and the bean shape of flux surfaces are considered. The calculation results show that the second harmonic extraordinary mode heating is effective even at low density if the launching direction is properly ad...

A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermod...

Volume Bragg gratings (VBGs) in photothermorefractive (PTR) glass are widely used for laser beam control including high-power laser systems. Among them, spectral beam combining based on VBGs is one of the most promising. Achieving 100+ kW of combined laser beams requires the development of PTR glass and VBGs with an extremely low absorption coefficient and therefore methods of its measurement. ...

Localized surface plasmon resonance is characterized by a significant electric field component normal to some parts the surface. Shaping the surface to be normal to the direction of an incident electric field may increase the incident power coupling to the excited plasmonic mode, enhancing the absorption in lossy nanowires. In this work we perform a numerical analysis to investigate the depende...

The indirect wavelength selective thermal emitter that we have proposed is constructed using a new microheater, demonstrating the enhancement of the emission peak generated by the surface plasmon polariton. The thermal isolation is improved using a 2 μm-thick Si membrane having 3.6 and 5.4 mm outer diameter. The emission at around the wavelength of the absorption band of CO₂ gas is enhanced. Th...

We demonstrate improved efficiency and dynamic range for two-photon absorption at 1.5 microm in a photoelectron-counting GaAs photomultiplier tube. cw laser measurements show pure two-photon absorption occurring in the device from average powers of 1.3 microW to nearly 1 mW. We use the detector to implement an autocorrelator with peak-power x average-power sensitivity of 1.7 x 10(-4) (mW)(2) an...

Lam Hui, Nickolay Y. Gnedin and Yu Zhang Absorption lines in the Lyα forest can be thought of as peaks in neutral hydrogen density along lines of sight. The column density distribution (the number density of absorption lines as a function of column density) is then a statistic of density peaks, which contains information about the underlying power spectrum. In particular, we show that the slope...

With the conservation of power, a phase diagram defined by amplitude square and phase of scattering coefficients for each spherical harmonic channel is introduced as a universal map for any passive electromagnetic scatterers. Physically allowable solutions for scattering coefficients in this diagram clearly show power competitions among scattering and absorption. It also illustrates a variety o...

We report the results of a 3C273 observation performed during the Science Verification Phase (SVP) of the BeppoSAX satellite. The broad-band spectrum is well represented by a power-law between∼ 1 keV and 200 keV. The spectral slope is flat (Γ ∼ 1.6), with a weak emission line at ∼ 6.4 keV (rest frame) of EW ∼ 30 eV. Below 1 keV, a deviation from a power-law due to an absorption feature plus a s...

We report high-resolution saturated-absorption spectra recorded by use of a few microwatts of radiation generated in a single pass by difference-frequency mixing. These results were obtained without the use of buildup cavities for the nonlinear mixing or for the saturation spectroscopy. We show high-quality saturated-absorption signals for the fundamental rovibrational band of CO(2) near 4.3 mu...