CCD array

Figure C 1.5.13. Schematic diagram of an experimental set-up for imaging 3D single-molecule orientations. The excitation laser with either s- or p-polarization is reflected from the polymer/water boundary. Molecular fluorescence is imaged through an aberrating thin water layer, collected with an inverted microscope and imaged onto a CCD array. Aberrated and unaberrated emission patterns are observed for z- and xr-orientated molecules, respectively. Reprinted with pennission from Bartko and Dickson [148]. Copyright 1999 American Chemical Society.

Infrared arrays do not have any charge transfer, since the charge is amplified at each pixel by the silicon multiplexer. Only CCDs have charge transfer and thus this section only discusses CCD array architecture. 

Figure 19. CCD array architecture, showing the parallel and serial transfers required to move the pixel charge to the output amplifier.

In practice the pdf of the image is sampled using a CCD array with finite pixels. Using A to denote the pixel width and 5 to describe the offset from the origin to the first pixel the centroid can be computed from... 

A CCD array collects simultaneously the spectral data emanating from an array of spatial locations on the irradiated sample surface [20]. Thus, recorded is a three-dimensional data cube, with two coordinates representing the sample and one for the spectral dimension at each (x,y) point (cf. Figure 2). The spectral dimension in this case is only the intensity of a certain Raman band, used to identify the component of interest. This band should be unique for the component of interest of the sample and its intensity should be high enough in... 

GC Holst. CCD Arrays, Cameras and Displays. Co-published by SPIE and JCD Publishing Co. SPIE Press, Vol. PM57, 1998. 

Clearly visible in the spectrum are the Ka and the K[3 components of X-ray emission generated by fast electron propagation in the substrate of the Ti foil target. Also visible in the spectrum is a small feature at 2.7 keV due to a small number of events in which a Ka photon from an excited atom of the Si substrate of the CCD array escapes from the detector sensitive area. 

Fig. 7.8. Raw energy distribution in ADC units of all the X-ray photons plotted according to their landing position on the x-y plane of the CCD array...

TB) which can be detected with a CCD array and a laser beam reflection technique. This system was able to resolve easily a 100 nm change in thickness and was also able to measure the dynamic change of thickness. The preload applied to the pin on TB of l mm diameter was varied from 0.08 g to 1.0 g with a weight (TW). From this, zero-preload deformation was obtained by extrapolation. The Poisson ratio was about 0.08 in water at the longitudinal load of 0.12 MPa, which was close to or lower than that obtained from the width change. 

Besides space charge, image quality is limited by the combination of the number of pixels of the CCD camera and the size of a single ion event. The PSD usually employs two micro-channel plates (MCPs) mounted in a chevron configuration and backed by a phosphor screen. A product ion causes an electron cascade through the channel plates and onto the phosphor, which emits a pulse of diffuse light that must be focused properly onto the CCD array with a camera lens or fiber optic taper. In this process one product ion results in a signal on the CCD that is usually several pixels... 

The initial studies described above were conducted on Raman microspectrometers on extracted human teeth. In order to translate this research from the laboratory bench to the dental chair side, the next step it is to develop dedicated systems for clinical use. A key element to this development is the use of fibre-optic probes to allow measurements in vivo. We recently reported a study in which optical fibres were used for PRS measurements [48], Although not yet fully realized into a dental probe, this study demonstrated the design and feasibility of acquiring parallel- and cross-polarized Raman spectra via a bifurcated optical fibre whose distal terminal has the two fibres aligned vertically for simultaneously collecting spectra from the two polarization channels on a 2D CCD array. Simultaneous data acquisition will allow for more rapid measurement times in vivo. 

Cosmic rays hit the CCD array at random times with arbitrary intensity, resulting in spikes at individual pixels. When the array is summed and processed, sharp spectral features of arbitrary intensities may appear in the Raman spectra. These artifacts are typically removed before multivariate calibration. 

The UV visible measurements are performed using a commercial HR 2000 high-resolution fibre optic Ocean Optics spectrophotometer equipped with a halogen light source HL2000. The detector is a linear silicon CCD array. The spectral resolution measured with a Hg-Ar calibration lamp is better than 0.2 nm. 

Linear PDA or CCD array (may have 3 arrays for RGB) 1,000-10,000 128-8,192 8-12 bits/pixel Serially transmitted pixel data Custom software... 

Fig. 2. Reflections of the 7rN and jiO (5 — 4) transitions recorded simultaneously with a large-area CCD array. (The horizontal and vertical extensions of the CCD array are not in scale for the scatter plot)...

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