Diffraction grating blaze angle

Figure 3.4 Echelle grating (a angle of incidence, (3 angle of diffraction, 0 blaze angle, 2<5 angle between incident and diffracted ray at blaze maximum, W ruled grating width)...

Question. A diffraction grating has a ruled area that is 10.40 cm wide, has 600.0 grooves per millimetre and is blazed at an angle of 45.00°. 

Fluorescence Instrumentation and Measurements. Fluorescence spectra of the FS samples were obtained on a steady state spectrofluorometer of modular construction with a 1000 W xenon arc lamp and tandem quarter meter excitation monochromator and quarter meter analysis monochromator. The diffraction gratings In the excitation monochromators have blaze angles that allow maximum light transmission at a wavelength of 240 nm. Uncorrected spectra were taken under front-face Illumination with exciting light at 260 nm. Monomer fluorescence was measured at 280 nm and exclmer fluorescence was measured at 330 nm, where there Is no overlap of exclmer and monomer bands. 

Fig. 5 Diffraction grating. Ng = normal to the grating Nf = normal to the face of the grating A = angle of incidence 0 = angle of diffraction d = grating spacing and B = blaze angle.

Fig. 18. Spectral dispersion at a diffraction grating, a Grating constant, / Blaze angle, t/tp. angle of incident radiation, 2. angle of diffracted radiation with wavelength X.

The symbols used are as follows / = angle of incidence, 0 = angle of diffraction (or reflectance), p = blaze angle of the grating, d = grating spacing. (Modified from Dean, J.A. and Rains, T.C., eds.. Flame Emission and Absorption Spectrometry, Vol. 2, Marcel Dekker, Inc., New York, 1971. Used with permission.)... 

By driving the Opto-VLSI with blazed gratings of different pitches, as shown in Fig. 3, optical beam steering can be achieved. The diffraction (or steering) angle for an Opto-VLSI processor, am, is given by (Xiao et ah, 2008) ... 

With a blaze angle 6 = a = P = 30° and a step height h = A, the grating can be used in second order, while the third order appears dX P = Pq + 37°. With d = A/ tan 0 = 2A, the central diffraction lobe extends only to Po 30°, the intensity in the third order is very small. 

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