We present near-infrared (1 to 2.5 μm) low-resolution spectroscopy of eleven ultracool dwarfs with spectral types ranging from M7 to L8. Combining our observations with data published previously by Leggett et al. (2001), we have measured equivalent widths for the strongest atomic features and constructed narrowband indices to gauge the strength of the strongest molecular features. Those measure...

Fluorophores with near-infrared emissions play a crucial role in numerous bioimaging and biosensing applications, owing to their deep penetration depths, low auto-fluorescence, and minimal tissue damages. Herein, the rational development of a new class of near-infrared fluorophores with bright one-photon and two-photon emissions at ≈740 nm, large Stokes shifts (≈80 nm), significant two-photon a...

This work describes the techniques used to prepare and analyze a reflectance wavelength standard composed of three rare-earth oxides. A mixture of dysprosium oxide (DY20.1), erbium oxide (Er203). and holmium oxide (Ho20) provides a pressed powder specimen exhibiting a near infrared reflectance spectrum characterized by many discrete absorption minima in the wavelength range 700 to 2000 urn. The...

In this work we have investigated the performance of Schottky photodetectors based on materials nonconventionally used to detect near-infrared wavelengths. In the proposed devices the absorption mechanism is based on the internal photoemission effect. Both three-dimensional (sputtered erbium and evaporated germanium) and two-dimensional materials (graphene) have been considered and their perfor...

Near-infrared spectroscopy and imaging are non-invasive optical methods, which measure various parameters such as the absorption and scattering coefficient of tissue and the concentration of oxy and deoxyhemoglobin, water and fat. Near-infrared spectroscopy and imaging offer the possibility to non-invasively measure hemodynamic responses of the brain to external stimuli. The ability of near-inf...

As silicon photovoltaics evolve towards thin-wafer technologies, efficient optical absorption for the near-infrared wavelengths has become particularly challenging. In this work, we present a solution that employs combined micro- and nano-scale surface textures to increase light harvesting in the near-infrared for crystalline silicon photovoltaics, and discuss the associated antireflection and ...

The near infrared absorption of pure n-heptane between 5000 c m 1 and 6500 c m 1 was measured up to 250 °C and to pressures of 2000 bar. The procedure for measuring vibrational intensities at high pressures and temperatures with a precision of better than ± 1% is described. The integrated molar absorptivity of the combination mode va + vs of the methylene stretching fundamentals turns out to be...

A series of natural rhyolitic obsidians were analyzed for their total water contents by a vacuum extraction technique. The grain size of the crushed samples can significantly affect these analyses. Coarse powders must be used in order to avoid surface-correlated water. These analyses were used to calibrate infrared spectroscopic measurements of water in glass using several infrared and near-inf...

Development of a detector case for complete co-registration of images in a non-fiber-based combined near-infrared spectral tomography and digital breast tomosynthesis, required analysis to find materials that could support a breast under full mammographic compression without affecting the x-ray images or the quality of the near infrared measurements. Several possible solutions were considered, ...

The thermo-optical properties of coated surface are important for spacecraft thermal control coatings which depend on the optical properties and structure of the coating material. These coatings control the temperature by their capability of outer energy absorption and its emission. The optical properties of pigment can be improved if the pigment contains a high fraction of voids in its structu...