Absorption spectroscopy with tunable diode lasers (TDLAS) in the infrared region is a well-known technique for the chemical analysis of gas mixtures. The laser provides a high selectivity, which is important in industrial environments such as in-line stack monitoring, where complex gas mixtures are present. A wavelength tunable diode laser in the near infrared region has been utilized as a ligh...

Bismuth-substituted iron garnets are considered to be the most promising magneto-optical materials because of their excellent optical transparency and very high magneto-optical figures of merit in the near-infrared spectral region. However, the practical application of garnets in the visible and short-wavelength infrared parts of spectrum is currently limited, due to their very high optical abs...

Hyperspectral imagery from the airborne multispectral scanner was evaluated for discrimination and mapping of vegetation components in a semi-arid rangeland environment in Southern Australia. Automated unmixing of two image strips with 5-m resolution revealed several vegetation endmembers in the visible, near infrared (near-IR), and short-wave infrared portions of the imagery. Identity of the e...

Spectra measured by remote-sensing Fourier transform infrared spectrometers are often calibrated using two calibration sources. At wavenumbers where the absorption coefficient is large, air within the optical path of the instrument can absorb most calibration-source signal, resulting in extreme errors. In this paper, a criterion in terms of the instrument responsivity is used to identify such w...

New high quality Keck and ESO images of PKS 1830–211 are presented. Applying a powerful new deconvolution algorithm to this optical and infrared data, both images of the flat spectrum core of the radio source have been identified. An extended source is also detected in the optical images, consistent with the expected location of the lensing galaxy. The source counterparts are very red at I − K ...

The temperature dependence of the infrared absorption cross-sections of CFC-113 (1,1,2-trichlorotrifluoroethane) in a pure vapor phase has been recorded in the 600–1250 cm 1 spectral region using Fourier transform spectroscopy. Spectra at 0.05 cm 1 resolution have been used to derive the integrated band strengths of the five main absorption bands over a range of temperatures from 223 to 283 K. ...

Measurements of the quality factor Q approximately 8x10(9) are reported for the whispering-gallery modes (WGM's) of quartz microspheres for the wavelengths 670, 780, and 850 nm; these results correspond to finesse f approximately 2.2x10(6) . The observed independence of Q from wavelength indicates that losses for the WGM's are dominated by a mechanism other than bulk absorption in fused silica ...

We report the detection of the transverse optical vibrational band of water ice at 44 μm in absorption towards two embedded infrared sources, IRAS 18316–0602 (RAFGL7009S) and IRAS 19110+1045. The water band extending from 30 to about 80 μm is a prominent feature in the combined ISO SWS and LWS grating spectra. Using new optical constants for amorphous and crystalline water ice, we have modeled ...

Natural graphite shows little optical response. Based on first-principles calculations, we demonstrate, for the first time, that an in-plane pressure-induced slip between atomic layers causes a strong anomalous enhancement and large red-shifts in the infrared and far infrared optical absorption by graphite. Specifically, a slip along the armchair direction induces an absorption feature that red...

The surface-plasmon-mediated, extraordinary transmission of metallic arrays of subwavelength apertures has been used as the light source for absorption studies of self-assembled monolayers on metal. Enhanced infrared absorption spectra of a sequence of alkanethiol self-assembled monolayers on copper were recorded for carbon chain lengths varying from 8 to 18 atoms. Transition positions and inte...