Charge-coupled device linearity

Sihcon charge coupled devices (CCDs), commonly used in soHd-state video cameras and in research appHcations, are being appHed to low light level spectroscopy appHcations. The main advantage of area array CCDs over linear photodiode detectors is the two-dimensional format, which provides simultaneous measurements of spatial and spectral data. 

U. Heitmann, M. Schutz, H. Becker-Ross and S. Florek, Measurements on the Zeeman-splitting of analytical lines by means of a continuum source graphite furnace atomic absorption spectrometer with a linear charge coupled device array, Spectrochim. Acta Part B, 51, 1996, 1095-1105. 

Recently, an automatic color video image analysis system was developed to quantify antigen expression (androgen receptor) (Kim et al.,T999a). This system provides a linear relationship between the antigen content and mean optical density of the immunoperoxidase-substrate reaction product. Titration of antibody, concentration, and reaction duration of the substrate can be optimized with this system. The imaging hardware consists of a Zeiss microscope, a three-chip charge-coupled-device camera, a camera control board, and a Pentium-based personal computer. 

The classical silicon photodiode linear array manufactured by Reticon was the first detector marketed successfully. Similar solid state linear array detectors based on charge coupled devices, or charge.injection devices may also be of interest. Typical of the families of detectors, the Reticon detectors are built in a number of elements/array sizes. Commercially available units have anywhere from 128 to 1024 elements/array. Each individual element in the array is 1 x 1 mil to 1 x 100 mil in area, and are spaced on approximately 1 mil centers. The spectrometer system discussed in this article was built using Reticon-type devices. 

CCD = charge-coupled device IHIs = interligand hypervalent interactions ILL = Institut Lane-Langevin INS = inelastic neutron scattering IPNS = intense pulsed neutron source LINAC = linear accelerator MaNDi=macro-molecular neutron diffractometer NiMH=nickel-metal OPAL = open pool Australian light-water reactor hydride SANS = small-angle neutron scattering SNS = spallation neutron source. 

Fig. 20. Principle of a linear array Charge Coupled Device (CCD). (From Ref.

Sweedler J. V., Jalkian R. F. and Denton M. B. (1989) A linear charge coupled device detector system for spectroscopy, Appl Spectrosc 43 953-961. 

In spectrographs, the dispersing element is immobile and the spatially dispersed spectrum is recorded on a photographic plate or on a linear array charge-coupled device (CCD) detector. 

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