Mid-wave infrared

P. Martyniuk, W. Gawrott A. Rogalsld, Themetical modeling of HOT HgCdTe Barrier detectors for the Mid-Wave Infrared Range. J. Electron. Mat 42(11), 3309-3319 (2013)... 

K. Jozwikowski, A. Rogalski, A. Jozwikowska, Numerical modeling of fluctuation phenomena in semiconductors and detailed noise study of mid-wave infrared HgCdTe-heterostmcture devices. J. Electron. Mat. 31(7), 677-682 (2002)... 

MWIR - An acronym for mid wave infrared, describing the mid wave operating region of certain infrared instruments, from about 2 to 5 pm. 

Radio TV Microwave Millimetre wave Mid-infrared Near- infrared Visible Near- ultraviolet Far- ultraviolet X-ray Y-ray... 

Janotta M., Karlowatz M., Vogt F., Mizaikoff B., Sol-gel based mid-infrared evanescent wave sensors for detection of organophosphate pesticides in aqueous solution, Anal. Chim. Acta 2003 496 339-348. 

A fiber-optic device has been described that can monitor chlorinated hydrocarbons in water (Gobel et al. 1994). The sensor is based on the diffusion of chlorinated hydrocarbons into a polymeric layer surrounding a silver halide optical fiber through which is passed broad-band mid-infrared radiation. The chlorinated compounds concentrated in the polymer absorb some of the radiation that escapes the liber (evanescent wave) this technique is a variant of attenuated total reflection (ATR) spectroscopy. A LOD for chloroform was stated to be 5 mg/L (5 ppm). This sensor does not have a high degree of selectivity for chloroform over other chlorinated aliphatic hydrocarbons, but appears to be useful for continuous monitoring purposes. 

Most standard infrared spectrometers currently operating in the mid-IR spectral region feature single element detectors. Exceptions are analyzers that are equipped with multiple detectors dedicated to single wave-... 

Using Fourier Transform Infra Red (FTIR) spectroscopy, the reaction can be monitored. The progress of the reaction also can be followed by studying the reduction of the primary hydroxyl peaks in the mid-infrared spectra. The urethane band with the approximate wave number 1739 will be forming. The NCO band at 2273 will decrease from a maximum and then stabilize as the chain extension proceeds. 

There are three main infrared bands, namely, the near, mid-, and far infrared zones. The most commonly used band is the mid-range band covering 50 to 2.5 pm or, in wave numbers, 200 to 4000 cm4. The near infrared band that covers the range of 0.8 to 2.5 pm (wave numbers 12500 cm1 to near 4000 cm4) has overtones that have some importance to polyurethane processing. In this region, real-time studies have been carried out to follow the course of a reaction. (Wave numbers (in cm4) = 10000/wavelength (in pm).) The far infrared range does not have information that is relevant to polyurethane studies. 

Infrared radiation is divided into three regions the near-infrared from 800 to 3 (XX) nanometres, the mid-infrared from 3000 to 25000 nm and the far-infrared from 25000 to 10 nm. These subdivisions are arbitrary, essentially based on available instrumental possibilities but also on the type of information that can be accessed in each of these domains. It is customary to express the units in wave-numbers, v in cm" (v = v/c - I /X where vis the frequency in Hz. c the velocity of light and X the wavelength) which corresponds, for example, to 3 300 to 400 cm" for the mid-infrared. 

Forbidden pure rotational transitions of H3, following the selection rules Ak = +3, occur in the wide region from millimetre wave to mid-infrared.These transitions are caused by centrifugal distortions of the symmetric structure. No laboratory observation of them has been reported so far. These transitions are much weaker than the usual dipole-allowed rotational transitions in polar molecules, and their spontaneous emission rates range from ca. 10" s" to ca. 10" s". Nevertheless, such weak transitions may be observable in low-density regions just like the Hj quadrupole transitions. Also, the spontaneous emission lifetimes are short compared with the collisional time in low-density areas, making the forbidden rotational transitions important processes for cooling the rotational temperature of Hj. ... 

Historically, trimethylene oxide was the first ring molecule for which a ring-puckering potential was determined from spectroscopic data. It has been the most extensively studied ring molecule, having been investigated by far infrared, micro-wave, Raman and mid infrared techniques5,9 4S-S9). Several isotopic species have been synthesized and studied. 

D. Wiedmann, Mid-infrared trace-gas sensing with a quasi-continuous-wave Peltier-cooled distributed feedback quantum cascade aser,Appl. Phys. B (79), 907-913 (2004). 

In the near and the mid infrared, the absorption of light by matter originates from the interaction between the radiation from a light source and the chemical bonds of the sample. More precisely, if the atoms situated at the two extremes of a bond are different, they form an electric dipole that oscillates with a specific frequency. If such a non-symmetrical bond is irradiated by a monochromatic light source whose frequency is the same as the dipole, then an interaction will occur with the bond. Thus, the electrical component of the wave can transfer its energy to the bond on condition that the mechanical frequency of the bond and the electromagnetic frequency of the radiation are the same (Figure 10.1). This simplified approach can be used to rationalize that in the absence of a permanent... 

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