Charge Transfer Device Detectors for Analytical Optical Spectroscopy—Operation and Characteristics

Abstract

This article is the first in a two-part series describing the operation, characteristics, and application of a new class of solid-state multichannel UV-visible detectors. In this paper, charge transfer devices (CTDs) are described. Detector characteristics pertinent to spectroscopic application—including quantum efficiency, read noise, dark count rate, and available formats—are emphasized. Unique capabilities, such as the ability to nondestructively read out the detector array and the ability to alter the effective detector element size by a process called binning, are described. CTDs with peak quantum efficiencies over 80% and significant responsivity over the wavelength range of 0.1 nm to 1100 nm are discussed. Exceptionally low dark count rates, which allow integration times of up to many hours and read noises more than two orders of magnitude lower than those read by commercially available PDA detectors, contribute to the outstanding performance offered by these detectors.

Near-infrared spectroscopy and imaging in food quality and safety

“…A class of solid state multi-channel detectors for optical spectroscopy, which allows measurement of each wavelength interval in one single data sampling period, has two competing technologies, i.e., charge transfer devices (CTD) and photodiode array (PDA). Compared to PDAs, CTD have better spectral sensitivity and signal-to-noise ratio (S/N ratio) but have relatively high equipment cost [39]. Multi-channel detectors come in the form of linear array detectors and twodimensional imaging sensors.…”

Luminescence Digital Imaging Microscopy

“…Luminescence is generally a low-light level phenomenon. Thus, its detec tion in microscopes requires the use of sensitive detectors, of which several are available: (a) video cameras, newly enhanced with high-performance gated intensifi ers (184); (b) solid-state cameras with charge-coupled devices (CCD) (98) and charge-injection devices (CID) in linear or two-dimen sional arrays (24), which provide either video outputs, usually in a TV format, or slow-scanning frame rates along with much greater accuracy and precision, and which can also be intensifi ed (183,184); (c) micro channel-plate (MCP) cameras with photon-counting position-sensitive detection (PSD) (205) or coupled TV cameras (86); and (d) photodiode arrays with individual signal-processing paths (76).…”

Cherenkov laser under conditions of total internal reflection in a magnetostatic field

“…It should also be noted that the relative intensities of the spectral lines were different. In a spectrograph, each pixel senses light of different wavelengths and the quantum efficiencies of photosensitive silicon substrate vary with wavelength (Bilhorn et al 1987). In figure 5(a), for all emission spectral lines care was taken so that the CCD detector was not saturated and the 727.29 nm emission line was not observed.…”

“…Therefore, this type of instrument is quite suitable for harsh working environments (Williamson et al 1989). A linear array detector, which can either be a charge-coupled device (CCD) or a photodiode array (PDA), can scan full spectral signals simultaneously at high speed allowing the possibility for online quality monitoring (Bilhorn et al 1987). According to specific application requirements, a compact and rugged spectrograph system can be constructed with system performance comparable to scientific grade spectrometers (Engert et al 1994).…”