Infrared array detectors

NASA s Infrared Astronomy Satellite (IRAS), which was launched in 1985, consisted of a liquid-helium cooled telescope (60-cm mirror) and produced the first all-sky maps of the infrared universe at 25, 60, and 100 pm wavelength. IRAS was followed in 1996 with another cooled telescope in space, the Infrared Satellite Observatory (ISO), an ESA mission, which was a true observatory that could carry out follow-up observations of the IRAS sources. In 2003, NASA s Spitzer Space Telescope, with an 85-cm mirror, achieved major advances in sensitivity, image quality and field-of-view over ISO. Although its mirror was only slightly larger than ISO s 60-cm mirror, the use of new, sensitive, and large-area infrared array detectors has permitted this new view of the infrared universe. 

Based on infrared array detector technology, NIR chemical imaging techniques are the most popular in the market. Spatial, chemical, structural and functional information can... 

MoLean I S 1995 Infrared array detectors—performanoe and prospects lAU Symp. 167 69-78... 

B Chase, Y Talmi. The use of a near-infrared array detector for Raman spectroscopy beyond one micron. Appl Spectrosc 45 929-931, 1991. 

FWHM) of the mutual correlation function representing the temporal overlap of the pump and probe pulses. The wavenumber resolution in such measurements depends on the following. If the probe pulse having a narrow spectral bandshape is directly detected by an infrared detector such as an MCT detector, the wavenumber resolution is decided by the bandwidth of such probe pulses. If the probe pulses cover a wide infrared region, and it is necessary to use an infrared polychromator and to detect the monochromatic radiation by an infrared array detector such as an MCT array detector, the wavenumber resolution of such a measurement system is determined by both the wavenumber resolution of the polychromator used and the pixel resolution of the array detector. 

Abstract. This paper describes the design, expectations, and prototyping of a new allsky survey, called 2MASS (Two Micron All Sky Survey) to be carried out with the new generation of infrared array detectors. 

Sohd-state multi-element detector arrays in the focal planes of simple grating monochromators can simultaneously monitor several absorption features. These devices were first used for uv—vis spectroscopy. Infrared coverage is limited (see Table 3), but research continues to extend the response to longer wavelengths. Less expensive nir array detectors have been appHed to on-line process instmmentation (125) (see Photodetectors). 

Such effects principally cannot be observed in multi band detectors such as a UV diode array detector or a Fourier transform infrared (FTIR) detector because all wavelengths are measured under the same geometry. For all other types of detectors, in principle, it is not possible to totally remove these effects of the laminar flow. Experiments and theoretical calculations show (8) that these disturbances can only be diminished by lowering the concentration gradient per volume unit in the effluent, which means that larger column diameters are essential for multiple detection or that narrow-bore columns are unsuitable for detector combinations. Disregarding these limitations can lead to serious misinterpretations of GPC results of multiple detector measurements. Such effects are a justification for thick columns of 8-10 mm diameter. 

The infrared radiation caused by the heat of reaction of an enantioselective enzyme-catalyzed transformation can be detected by modern photovoltaic infrared (IT)-thermographic cameras equipped with focal-plane array detectors. Specifically, in the lipase-catalyzed enantioselective acylation of racemic 1-phenylethanol (20), the (K)- and (S)-substrates were allowed to react separately in the wells of microtiter plates, the (7 )-alcohol showing hot spots in the IR-thermographic images (113,114). Thus, enantioselective enzymes can be identified in kinetic resolution. However, quantification has not been achieved thus far by this method, which means that only those mutants can be identified which have E values larger than 100 (113-115). 

Kirkwood, J., Al-Khaldi, S. F., Mossoba, M. M., Sedman, J., and Ismail, A. A. (2004). Fourier transform infrared bacteria identification with the use of a focal-plane-array detector and microarray printing. Appl. Spectrosc. 58,1364-1368. 

Near-infrared spectral imaging with focal plane array detectors... 

Marcott, C., Reeder, R. C., Paschalis, E. P., Talakis, D. N., Boskey, A. L. and Mendelsohn, R. (1998) Infrared microspectroscopic imaging of biomineralized tissues using a mercury-cadmium-telluride focal-plane array detector. Cell. Mol. Biol. 44, 109-115. 

Marcott, Curtis and Reeder, C. Robert (1998) Industrial applications of FUR microspectro-scopic imaging using a mercury-cadmium-telluride focal-plane array detector. Proceedings of the SPIE - Infrared Technology and Applications XXIV, Vol. 3436, 285-9. 

The ideal high-throughput analytical technique would be efficient in terms of required resources and would be scalable to accommodate an arbitrarily large number of samples. In addition, this scalability would be such that the dependence of the cost of the equipment to perform the experiments would scale in a less than linear manner as a function of the number of samples that could be studied. The only way to accomplish this is to have one or more aspects of the experimental setup utilize an array-based approach. Array detectors are massively multiplexed versions of single-element detectors composed of a rectangular grid of small detectors. The most commonly encountered examples are CCD cameras, which are used to acquire ultraviolet, visible and near-infrared (IR) photons in a parallel manner. Other examples include IR focal plane arrays (FPAs) for the collection of IR photons and channel electron multipliers for the collection of electrons. 

Lewis, E. N., Treado, R J., Reeder, R. C. et al. (1995) Fourier transform spectroscopic imaging using an infrared focal-plane array detector. Anal. Chem. 67, 3377-81. 

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