Infrared spectral range

Optical Properties. The optical transmission of vitreous siUca is influenced by impurities and the forming process. Ultrapure vitreous siUca has the abihty to transmit from the deep ultraviolet, through the visible, and into the near-infrared spectral range. 

In the infrared spectral range in general Fourier transform (FT) interferometers are used. In comparison with dispersive spectrometers FTIR enables higher optical throughput and the multiplex advantage at equivalent high spectral resolution. In... 

Guillot B., Bratos S. Theoretical analysis of dielectric properties of polar liquids in the far-infrared spectral range, Phys. Rev. A 16, 424-30 (1977). 

Citterio D, Sasaki S, Suzuki K (2001) A new type of cation responsive chromoionophore with spectral sensitivity in the near-infrared spectral range. Chem Lett 30 552-553... 

The optical features of a center depend on the type of dopant, as well as on the lattice in which it is incorporated. For instance, Cr + ions in AI2O3 crystals (the ruby laser) lead to sharp emission lines at 694.3 nm and 692.8 nm. However, the incorporation of the same ions into BeAl204 (the alexandrite laser) produces a broad emission band centered around 700 nm, which is used to generate tunable laser radiation in a broad red-infrared spectral range. 

Mizeikis V, Seet KK, Juodkazis S, Misawa H (2004) Three-dimensional woodpile photonic crystal templates for infrared spectral range. Opt Lett 29(17) 2061-2063 Loader O, John S (2001) Proposed square spiral microfabrication architecture for large three-dimensional photonic band crystals. Science 292 1133-1135 Seet KK, Mizeikis V, Juodkazis S, Misawa H (2006) Three-dimensional horizontal circular spirals photonic crystals with stopgaps below 1 xm. Appl Phys Lett 88(22) 221101... 

One of the problems which must be solved for quantitative measurements by emission is the need for a blackbody source at the temperature of measurement. And a variety of blackbody references have been used including a V-shaped cavity of graphite 164), a metal plate covered with a flat black paint1S6 160) and a cone of black paper l53). However, none of these methods of producing a blackbody reference spectrum are adequate. In most cases the efficiency of the reference has not been established. The most recent recommendation 1S0) is an aluminium cup painted with an Epley-Parsons solar black lacquer which has an emittance of greater than 98% over the infrared spectral range. 

Different types of chemical reactions involve different types of vibrational modes, e.g. dissociation reactions may be controlled by stretching vibrations, isomerizations by skeletal modes, and so on. The argument that infrared quanta are relatively energy-poor and infrared transitions generally have low absorption cross sections, especially if multiphoton excitation is required, limits the choice of suitable molecular transitions. With respect to these constraints the type of reaction chosen and described below was dissociation, involving molecules with maximal transition dipole moments, comparatively weak bonds to be broken, and vibrational excitation in the mid-infrared spectral range. 

The lack of accurate and stable frequency standards in the near-infrared spectral range, and in particular at 1083 nm, is a serious inconvenient to improve the present frequency stability of the He-locked master laser. On the other hand, hyperfine transitions of the iodine molecule has been defined as secondary frequency standard at different visible wavelengths, and in particular at 532 nm, the doubled frequency of the 1064 nm Nd YAG laser. Likewise, our idea has been to lock the master laser frequency to I2 hyperfine transitions at its doubled frequency, 541 nm. 

In any case however, antipodal helices cause countercurrent spectra of the optical rotation, so that the observation of just a single Cotton effect is sufficient to discriminate the antipodes and, in case, enantiomeric solutes. For such an experiment the choice of the infrared spectral range is no longer dictated by the structure period but by the presence of suitable transition moments. The low demand for the chiral solute to be characterized (Korte, 1978) is exemplified by Fig. 4.6-14. In the 20 im wide sample cell an area of 3 mm times 3 mm was filled with approximately 200 pg solution containing circa 0.2 pg of either S-(-) or R-(-i-) Thalidomide (Contergan) in a nematic solvent. In the spectral interval shown, at least three oppositely shaped ACE are found, the pronounced one around 836 cm is related to the 7 (C- H), phenyl-H out-of-plane vibration of the... 

The infrared spectral range is usually served by Fourier transform spectrometers, which contain an interferometer for wavelength dispersion. Today, the spectra are immediately calculated by using Fourier... 

High enhancement of the copper localized surface plasmon absorbency was recorded at the two-layer planar system consisted of copper and silver nanoparticles prepared with successive vacuum evaporation. The result obtained may be caused by strong near-field coupling in the close-packed binary system. The effect may be used for the development of high-absorptive coatings and spectral selective nanoelements in the visible and near infrared spectral ranges. 

D. Day, M. Gu, and A. Smallridge, Two-Photon Optical Storage in Photorefractive Polymers in the Near-Infrared Spectral Range. In Infrared Holography for Optical Communications, Techniques, Materials, and Devices, Vol. 86 P. Boffi, D. Piccini, and M. C. Ubaldi, Eds., Springer-Verlag, Berlin, 2003, p. 75. 

This investigation is based on data of the Advanced Very High Resolution Radiometer operated on the weather satellite series of the National Oceanic and Atmospheric Administration of the United States of America. The first instrument was launched in 1978. Three versions of the multichannel scanning radiometer were operated at 13 satellites and measured in 5-6 channels in the visible, near-infrared and thermal infrared spectral range, as defined in Table 9.1. 

Phytoplankton blooms can be monitored also from space. The oceanographic ocean color sensors installed on satellites measure the visible and near-infrared spectral range to identify optically active water constituents, such as chlorophyll, yellow substance, and suspended matter, and to perform a required atmospheric correction. The polar orbit and the swath of most oceanographic sensors permit a daily coverage of the Baltic Sea with a spatial resolution of 1 km, or better. The synoptic character and the repeating rate allow studies of the spatial and temporal development of the phytoplankton nearly in real time. 

In contrast, the nonlinearities in bulk materials are due to the response of electrons not associated with individual sites, as it occurs in metals or semiconductors. In these materials, the nonlinear response is caused by effects of band structure or other mechanisms that are determined by the electronic response of the bulk medium. The first nonlinear materials that were applied successfully in the fabrication of passive and active photonic devices were in fact ferroelectric inorganic crystals, such as the potassium dihydrogen phosphate (KDP) crystal or the lithium niobate (LiNbO,) [20-22]. In the present, potassium dihydrogen phosphate crystal is broadly used as a laser frequency doubler, while the lithium niobate is the main material for optical electrooptic modulators that operate in the near-infrared spectral range. Another ferroelectric inorganic crystal, barium titanate (BaTiOj), is currently used in phase-conjugation applications [23]. 

Appreciable absorption begins in the infrared spectral range above a wavelength of 4.0pm, as shown in Table 24 there are absorption peaks at 17.24pm (580cm-1) and 22.73pm (440cm-1), which result from lattice vibrations. For more details see [49],... 

Table 24 Refractive index, n, and absorption index, k, of the ordinary ray for sapphire in the infrared spectral range, at 25°C, from [49] ...

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