Diffractive order

Using the Rayleigh criterion, the resolution of the mth diffraction order is then given by... 

When a grating is used to excite the modes, usually the waveguide film is periodically modulated at the film/cover or film/substrate (or at both) interface (Fig. 15.4b). The incident beam illuminates this grating and one of the diffraction orders will excite the modes. The mode s effective refractive index can be calculated from the so-called grating equation10,30. 

Where in this expression a and b are the width and spacing between the slits of the grating, and hence d (= a + b) is defined as the grating constant. Here d and X are measured in the same units of length. The diffraction order is given by p, an integer value. 

Monolayer structures and epitaxial growth of vapor-deposited crystalline phthalocyanine films on single crystal copper substrates were studied using low energy electron diffraction Ordered monolayers of three different phthalocyanines, copper, iron, and metal-free, were seen on two different faces of copper, the (111) and (100). The monolayer structures formed were different on the two crystal faces and the several phthalocyanines yield nonidentical monolayer structures. 

X-ray diffraction (study of the respective intensities of the different diffraction orders)75, and electron microscopy11. ... 

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