Question

What is grating? define grating constant?

Answer 1

For a diffraction grating, the grating constant is the number of lines (or slits) per unit length (eg lines per cm).

Thus, the distance between the grating lines is 1/grating constant.

Answer 2

Answer:

• Grating is an arrangement composed of a big amount of equal width parallel slits separated by equal opaque spaces.
• It is acquired with the assistance of a diamond on a glass plate by controlling equidistant parallel lines.
• The lines act as opaque spaces and they cannot be passed by the incident light.
• The space between the two lines is transparent to light and functions as a slit.
• The spacing between the rows is in the order of visible light wavelength.
• The amount of rows in an aircraft transmission grating is in the order of 15000 to 20000 per inch.
• If the two successive slits a and b and the opaque spacing the grating constant will be (a+b).