Grating mechanically ruled

The first observations on the development of periodic modulations were made on Pt surfaces annealed in vacuum in the temperature range 920 to 1300C[9J. The 1-dimensional grating structures were made by mechanically ruling portions of gratings on polycrystalline Pt specimens. Annealing caused extensive... 

Holographic grating A grating that has been produced by optical interference on a coated glass plate rather than by mechanical ruling. 

Briefly describe how a holographic grating is produced. What is the advantage of this approach over a mechanically ruled grating ... 

Diffraction grating The most common gratings are made of reflecting or transparent sheets marked with fine parallel and equally spaced grooves or rulings. The grating separates polychromatic electromagnetic waves into their components. Similar results can be produced with a prism, but the mechanism is quite different. Fraunhofer used very fine parallel wires in his experiments. 

Figure 25-8 Mechanism of diffraction from an echellette-type grating. Angle i from the grating normal is the angle of the incident beam angle r is the angle of the reflected beam. The distance between successive rulings is d.

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