CCD spectrometer

Carl Zeiss Inc. [Online], On-line Eluorescence Measurements in Biotechnology using a Eiber Optical Probe and a Light Sensitive CCD Spectrometer, available http //www.zeiss.de/cl2567bb00549f37/Contents-Erame/ b98a7597898099dfcl25727d0047c6bc accessed 20 November 2009. 

Figure 8 A schematic of the reactor used to synthesize the nanoparticles described in this chapter. Cd and Se precursor solutions are stored in two separate syringes and injected at flow rates Ft and F2 into the two inlets of a y-shaped microfluidic device. The microfluidic device rests on a hot plate of variable temperature T. The reagent streams meet at the point of confluence and nucleation, and growth of the particles occurs as they pass along the outlet channel. The emission spectra of the particles so produced are monitored prior to collection at a detection-zone downstream of the chip using a 355-nm Nd YAG laser as an excitation source and a fiber-optic-coupled CCD spectrometer.

Our experimental setup of the 2D-CARS microscope is shown in Fig. 5.4h [32], The 70-fs output from the Ti sapphire oscillator was split into two beams. One of the beams was introduced into a photonic crystal fiber (Crystal Fibre, Femtowhite 800) to generate a coherent supercontinuum. Then, the continuum was conditioned with an 800 nm long-pass filter. The other beam was spectrally narrowed by the custom-made laser line filter (Optical Coatings Japan, Av = 14 cm FWHM). The obtained two beams were introduced collinearly into the microscope objective lens. The chirping of the broadband pump beam was carefully avoided so that the CARS signals are obtained in a wide spectral region. The broadband CARS emission in back-reflected direction was analyzed by the CCD spectrometer. 

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.

For either multiplex (e.g., FT-Raman) or multichannel (e.g., CCD) spectrometers, tM is the appropriate time to insert in Eq. (3.6) or (3.7). Second, a multichannel system can obtain a complete spectrum 1/Nr times faster than a single-channel system, while maintaining the same measurement time and signal strength per resolution element. Of course, both of these statements assume that other variables are equal for both spectrometer types. In Chapter 4, we will see that Im strongly affects SNR, but that the effects are fundamentally different for multichannel as opposed to multiplex spectrometers. 

Figure 4.7. Spectra of solid dextrose, obtained with 785 nm excitation and a dispersive/CCD spectrometer. Spectrum C is an average of fifty O.I sec CCD integrations and shows no improvement in SNR over a single 0.1 sec integration spectrum A), due to the dominance of readout noise.

Figure 839. Raman spectra of solid dextrose obtained at 785 nm (50 mW) and a dispersive/CCD spectrometer, with a range of integration times. Note the large change of intensity scale between spectra A and B. The short integration time (0.01 sec) yields poor SNR, while the long integration time (15 sec) yields truncated peaks.

As described in Section 8.2.1.1, there is a trade-off between resolution and spectral coverage for a dispersive CCD spectrometer. For a given grating... 

The discussion of dispersive CCD spectrometers presented thus far has considered the CCD to be one dimensional, with Nc pixels along the wavelength axis. The vertical (slit) axis of the CCD is usually binned into one (or a few)... 

Figure 9.19. (A) Fourier transform of interferogram of Figure 9.18A, showing entire Raman shift range (B) expansion of A over 300- to 1800 cm range. (C) FT of Figure 9.18B. (D) FT of Figure 9.18C showing resolution improvement from data reflection. (E) Spectrum of naphthalene obtained with dispersive/CCD spectrometer, 5 sec, 135 mW. (Adapted from Reference 22 with permission.)...

Figure 10.7. Spectra of cyclohexane obtained on FT-Raman and dispersive/CCD spectrometers, without correcting for instrument response function.

The procedure below was developed for a dispersive CCD spectrometer used daily to acquire response-corrected Raman spectra. The calibration procedure was conducted at the beginning of each session or after the grating was repositioned to cover a different Raman shift range. The calibration steps were automated for the most part, so the time required from the user was approximately 5 min before each session. This procedure may be adapted to a particular spectrometer and application, guided by the objective of resulting in a known level of accuracy of Raman shift and relative intensity, and providing a daily record of instrument performance. 

Figure 13.23. SERS spectrum of BPE on vapor-deposited silver islands, from 6 fmol of BPE contained within the laser spot 514.5 nm, 43 mW on a 1 pm spot, 5 sec integration on a disper-sive/CCD spectrometer. (Adapted from Reference 30 with permission.)...

There is some difference in the standard deviations when line and background intensities are measured simultaneously, as in the case of photographic detection or with modern CCD spectrometers, or when they are measured sequentially as done in slew scanning systems. Indeed, in the first case the fluctuations of line intensities and background intensities for a considerable part are correlated, especially at low signal levels and thus partially cancel. This may lead to a considerable gain in power of detection. 

Dc arc work has been given new impetus since the availability of CCD spectrometers, allowing simultaneous detection of all spectral lines photoelectrically, which could be expected to revive dc arc work for general survey analyses (see e.g. Ref. [359]). 

Z.-D. Zhou, G.-R Zhong, Q. Tan, Y. Li, X.-D., On-line spectrophotometric system based on pseudo liquid drop and handheld CCD spectrometer for monitoring formaldehyde level in wastewater, Instrum. Sci. Technol. 33 (2005) 297. 

Standards of AA CCD spectrometer Derivatized with FITC and 5-iodoacetamido fluorescein (5-IAF) CZE... 

Figure 10.6 Schematic diagram of the setup for optically pumped photoluminescence measurements. The excitation polarization was varied by a half-wave plate. The emitted light was collected by the CCD spectrometer along the direction parallel to the sample surface. Reproduced from H. Yanagi, 5. Hotta, S. Kobayashi and F. Sas i, Low-dimensional jt-conjugating oligomer crystals - Raman laser action and pulse-shaped emission with time delay, Oyo Buturi, 75, 1471-1475 (2006) with permission of The Japanese Society of Applied Physics...

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