Question

Resolving power of plane transmission grating derivation

Answer 1

Resolving power of a plane transmission grating. The resolving power of a diffraction grating is defined as its ability to form separate diffraction maxima of two closely separated wave lengths. The expression for resolving power of agrating can be obtained with the aid of Fig. 14.20.

Answer 2

The ability of an optical system to create distinct pictures of objects separated by short angular distances is called resolving power.

• The ability of a diffraction grating to create independent diffraction maxima of two closely separated wavelengths is defined as its resolving power.
• If λ and λ + dλ are wavelengths of two neighboring spectral lines, the resolving power of the grating is the ratio λ/dλ.
• This is measured by λ/dλ where dλ is the smallest difference between two wavelengths an λ is mean wavelength.