We report spectrally selective IR absorption enhancement in the defect-free photonic crystal cavities, via Fano resonances. For a symmetric slab structure (air-slab-air membrane) with an absorptive layer in the center of the slab, enhanced absorption can be observed with enhancement factor ~180 for certain range of r/a values at wavelength of 4 μm. Similar results can also be achieved in an asy...

New mid-infrared (10 and 20 μm) spectro-photometry of the ultraluminous infrared galaxy IRAS 08572+3915 is presented. The 10 μm spectrum reveals a deep silicate absorption feature, while the 20 μm spectrum shows no clear evidence for an 18 μm silicate absorption feature. An interstellar extinction curve is fitted to IRAS 08572+3915 and two other deep silicate infrared galaxies, NGC 4418 and Arp...

Infrared detector has a wide range of applications. To fabricate an IR detector with good sensitivity, an efficient IR absorber is needed. In this paper, we theoretically and experimentally investigated the absorption characteristics of Ti, multi-layer structured Ti-SiO2 and TiNx-SiNx nano films. The multi-layer structured TiNx-SiNx films with different nitrogen contents and Ti nano films with ...

The far-infrared conductivity of single-wall carbon-nanotube ensembles is dominated by a broad absorption peak around 4 THz whose origin is still debated. We observe an overall depletion of this peak when the nanotubes are excited by a short visible laser pulse. This finding excludes optical absorption due to a particle-plasmon resonance and instead shows that interband transitions in tubes wit...

Near infrared spectroscopy (NIRS) is a noninvasive optical technology that relies on the relative transparency of biological tissues to near infrared light (700-900 nm) to determine tissue oxygenation. Oxy and deoxy hemoglobin and cytochrome aa3 possess distinct absorption characteristics in the near infrared spectrum. By monitoring absorption at wavelengths where oxyand deoxyhemoglobin and cyt...

New synchrotron infrared absorption and reflectivity techniques have been developed to test predicted band overlap metallization in H 2 and D2 above 150 GPa at various temperatures. Measurements on both isotopes to maximum pressures of 216 GPa show no evidence for Drude excitations in the midinfrared to near-infrared spectrum. The most definitive are measurements on D 2, which remains transpare...

A room temperature operating Vertical External Cavity Surface Emitting Laser is applied around 1550 nm to intracavity laser absorption spectroscopy analyzed by timeresolved Fourier transform interferometry. At an equivalent pathlength of 15 km, the high resolution spectrum of the semiconductor disk laser emission covers 17 nm simultaneously. A noise equivalent absorption coefficient at one seco...

A survey of quasar absorbers was conducted using the Infrared Astronomical Satellite (IRAS) database. Quasars with known intervening absorption-line systems and broad absorption line (BAL) QSOs were selected primarily from the Junkkarinen, Hewitt & Burbidge catalog (1991). Of the 570 quasars with IRAS data, 52 showed 3 or better detections in at least one band in SCANPI analysis. The origin of ...

Perdeuterated 4’-pentyl-4-cyanobiphenyl ~D5CB! was synthesized and its physical properties evaluated and compared to those of 5CB. D5CB retains physical properties similar to those of 5CB, such as phase transition temperatures, dielectric constants, and refractive indices. An outstanding feature of D5CB is that it exhibits a much cleaner and reduced infrared absorption. Perdeuteration, therefor...