Detector types optical

Infrared spectra were taken with a Michelson-Genzel type FTIR instrument (IR/98, IBM Instruments, Inc.) equipped with a liquid nitrogen cooled HgCdTe detector. The optical attachment arrangement is shown in Fig. 2-14. The infrared radiation was p-polarized using ERS-5 wire grid polarizer. 

The detection performance of an LIF photometric device is governed by the emission filter(s), excitation filter(s), detector type, the excitation source and the detection scheme. The selection of optical elements and device configuration as it relates to the detection performance is further described by expanding the collection efficiency term in Equation 11.3 ... 

Figure 6.69 gives an example for an optical current sensor. The light path is wound around a current-carrying conductor equidirectionally with the azimuthal magnetic field of the current. The rotation of the plane of the electric vector is not detectable on its own and is converted to light intensity variations by a polarizer/analyser combination. A photo diode is used as a light intensity detector. The optical sensor itself is installed in the - e - compartment, the electronics shall be protected in an adequate type of protection, e.g. in a small flameproof - d - enclosure or in encapsulation - m -. In the special case of an energy distribution system with combined - e - and - d - compartments, the optical fibres may enter the d-compartment to the electronics inside via bushings complying with d -standards EN 50018 or IEC 60079-1 respectively (Fig. 6.70). The evacuation of the sensors into the e-compart-ment results in additional available space in the more expensive d-compart-ment, compared with increased safety - e -. ...

The chalcogenides of Be, Zn, Cd, and Hg are often referred to as II-VI semiconductors. They all have a zinc blende-type structure. The band gap decreases with increasing size of the metal from 3.0 eV in beryllium to 0.02 eV in mercury. The II-VI semiconductors find applications in solar cells, IR detectors, and optical conununication devices. 

In the deflection-type RI detector, the optical system is designed differently. The light beam actually passes... 

Some additional selective detectors have been described, but their use in biochemical GC has been minimal thus far. Among them, most notably, belong various optical spectroscopic detectors as well as various element-specific detectors based on the solute combustion and measurement of electrolytic conductivity [128]. While little has happened during the last decade with further development of the latter detector types, various gas-phase optical devices remain among the most interesting detectors for future studies. Element-specific plasma devices [129], UV absorption... 

In order to be consistent with the earlier chapters of this volume the detector advances are segregated into general detector types (thermal, photoconductor and photovoltaic, photoemissive, charge transfer devices, and heterodyne). The final section of this chapter presents future detector and related technology advances (from the author s point of view) that would greatly enhance our ability to use optical and infrared detectors to solve basic problems of our society. 

Photon detection is generally used from the vacuum ultraviolet to the near infrared and thermal detection from the mid-infrared onwards although there is some overlap. Figure 2 shows detector types for optical spectroscopy and detectors. 

List of detector types (e.g.opticaL ionization chambers, temperature sensors)... 

In this type of detectors, measured optical radiation causes emission of electrons from the surface of a photocathode in a vacuum tube. Electrons may reach direcdy the anode or first be multiplied on dynodes (photomultiplicators). Historically, these have been the first photodetectors. Table 1.4 presents the basic types of vacuum detection tubes according to the photocathode type. 

The so-called microspectroscopy mapping technique has been developed by attaching a microscope equipped with special reflecting-type optics and focal plane array detectors to FTIR spectrophotometers. 

The structure of the eye is discussed in Section 12 of the Handbook of Optics (Alpern, 1978) and in Smith (1966, Chapter 5). For our purposes, consider a simplified model, the so-called reduced eye. shown in Figure 14.13b. It treats the eye as a simple lens, 17 mm from the focal plane. There are two detector types rods and cones. Near the center of the focal plane, the cones are about 1.5 pm in diameter and are tightly packed together. Near the edges, the cones are 5-8 pm in diameter, and the rods have a diameter of 2-5 pm. 

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