Czerny-Turner spectrograph

A detachable monochromator (19) developed by Spex Industries, was another approach in minimizing stray light. It is a modified Czerny-Turner spectrograph which can be coupled to the exit slit of a double monochromator and function as a variable bandpass, variable frequency filter. This accessory, while providing the versatility of a triple monochromator, does not add much mechanical and optical complexity and can be removed when not wanted. 

Czerny-Turner spectrograph spect A spectrograph used chiefly in laboratory work, which has a plane reflection grating and spherical reflectors for the collimator and camera. cher-ne t3rn 3r spek-tra.graf)... 

Figure 8.3. Schematic of a single grating Czerny-Turner spectrograph. Shading indicates envelope of light passing through the instrument, which disperses and focuses wavelengths at the focal plane.

Most modern laboratory Raman instruments use spectrographs with multielement detectors. Figures 3 and 4 show optical diagrams of the more important spectrographs used for Raman spectroscopy. The Czerny-Turner spectrograph and its many variants are the most popular. Concave grating spectrographs... 

The TSI 3000 Series Desktop LIBS comes in a variety of configurations, including 4 Czerny-Turner spectrographs with CCD detectors, and has a wavelength range of 190-950 nm. PMT detectors can be used, especially with multiple PMTs, with the drawback being that the wavelengths that can be monitored are fixed and limited to the number of detectors. 

Figure 8 Schematic of a Czerny-Turner spectrograph utilizing aperture sharing and two separate reflection gratings. By angling grating 1 with respect to the incoming radiation and grating 2, two different spectral ranges can be observed at the CCD detector. Note that the focusing mirrors are not shown.

J Reader. Optimizing Czerny-Turner spectrographs A comparison between analytic theory and ray tracing. J Opt Soc Am 59 1189-1196, 1969. 

An imaging spectrograph differs from a conventional (e.g., Czerny-Turner) design in that it maintains the one-to-one correspondence of the entrance slit and its image at the detector. So a circular fiber positioned at the entrance... 

The single grating instrument depicted in Figure 8.3 is very common in optical spectroscopy (1), but its application to Raman is relatively recent because of inadequate stray light rejection. The introduction of effective laser rejection filters (Section 8.2.5) removed this limitation and single spectrographs became attractive. They are simpler and more efficient than double or triple systems and usually much more compact. Variations of the classical Czerny-Turner... 

FIGURE 4-8. Photograph of a Czerny-Turner plane grating spectrograph. [Courtesy McPherson Instrument Corp.]... 

The principal advantages of the Czerny-Turner are its relative simplicity and wavelength flexibility. Because it is an all-reflective design, it is naturally achromatic. The Czerny-Turner is easy to scan and can accommodate multiple gratings. This makes the Czerny-Turner an attractive spectrograph for research systems that require flexibility to operate with many different lasers (e.g., for resonance Raman spectroscopy [99]),... 

FIGURE 3 Schematic representation of the most frequently used grating-based monochromators (A, B, C) and polychromators (D, E, F). A and D are known as Czerny-Turner design. Fastie-Ebert (B) and Littrow (C) have similar designs in that both use a single reflective mirror. A Rowland circle polychromator is depicted in E, and F represents an Echelle spectrograph. 

---