Silicon CCDs

The challenges of achieving high QE over the 0.3-1.1 m band is summarized in Eig. 14, which shows the optical absorption depth of photons in silicon with the range of thickness of different regions of a CCD. Figure 14, which we like to call the beautiful plot captures the information needed for understanding the QE of silicon CCDs. 

In US-A-3842274 an infrared semiconductor is capacitively coupled to a silicon CCD register array. 

In US-A-3842274 (The United States of America as represented by the Secretary of the Navy, USA, 15.10.74) an infrared semiconductor is capacitively coupled to a silicon CCD register... 

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. 

Figure 1.6. Spectra of solid glassy carbon obtained with a state-of-the-art spectrometer in 1985 (Spex 1403 double monochromator with photon counting PMT) and a multichannel/CCD spectrometer of 1996 (Chromex 250 spectrograph, back thinned silicon CCD) 514.5 nm laser at 50 mW in both cases measurement times and signal/noise ratios (SNR) as shown.

Figure 8.24. Typical of Q vs. X curve for a front-illuminated silicon CCD, with Raman shift ranges (0 to 3000 cm ) for several common lasers.

Figure 8.33. Temperature dependence of quantum efficiency for front-illuminated silicon CCD. Spectra of a broadband source with the CCD at the indicated temperatures were divided by a spectrum of the same source taken at 25°C. The observed Q at 750 nm was nearly independent of temperature. (Adapted from Andor Technologies product literature.)...

The detection efficiency of silicon is low above 20 keV. A higher-Z, pixellated, detector is therefore included behind the silicon CCD. The silicon is therefore thinned down to the active thickness to minimise unwanted absorption. Due to the depth of focus of the optics, the second detector may be up to 15 mm beJiind the silicon CCD. In order to determine changes in source continua above 20 keV and to resolve cyclotron lines, we require to combine high detection efficiency with an energy resolution of between 1-2 keV over the energy band 20-60 keV. We envisage the use of a hybrid array of diodes constructed on... 

The matrix array detector (128 x 128) associates P(VF2-VF3) copolymer with a silicon CCD matrix. This detector made by Thomson-CSF/LCR and TCS has been characterized al room temperature using an IR germanium optics. The following table summarizes the performances of this detector. 

There exists a wide variety of approaches to the use of charge transfer devices in infrared focal planes. We shall discuss five high packing density, high quantum efficiency, approaches appropriate for series-parallel scan 1) IR sensitive CCD, 2) ctirect injection hybrid, 3) direct injection extrinsic silicon, 4) accumulation mode extrinsic silicon, and 5) infrared sensitive CID with silicon CCD signal processing. The reader is referred to a review article by Steckl et al. for a comprehensive discussion of a number of other approaches not discussed here which include indirect injection pyroelectric detectors and Schottky barrier photoemissive injection [6.1]. Three approaches in our list of five do not require... 

Fig. 6.14. Series-parallel scan IR CID. Infrared sensitive IR CID modules are completely read out more than once a dwell time through a preamplifier into a silicon CCD signal processor. In the signal processor TDI is performed and then th% individual lines of imagery are ac coupled and multiplexed. Only the CID module itself is fabricated from IR sensitive material...

Two other major factors had impacted Raman spectroscopy for both qnalitative and quantitative work. Older systems had problems with reproducibility due to wavelength dependence of the silicon CCD detector response and jc-axis nonreproducibility, a result of inadequate spectrograph... 

Although other detector technologies exist, the current detector of choice for virtually all types of dispersive Raman spectroscopy is the silicon CCD (charge-coupled device) array. The CCD array meets more of the desired detector characteristics for Raman spectroscopy than any other currently available detector technology. These characteristics include the following ... 

Whereas silicon CCDs are currently the most applicable detector type for process Raman spectroscopy, there are other technologies that may play a role in the future as they mature. 

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