Use of diffraction grating for measuring the focal length and distortion of optical systems.

The paper presents an experimentally simple, accurate, and inexpensive method for measuring the focal length and distortion of optical systems using a diffraction grating, where both of the properties are determined from the transversal distances of diffraction maximums in one measurement. The proposed approach does not require any special components or any expensive equipment. A detailed theoretical analysis is performed, and the estimation of uncertainties is studied as well. Afterward, the method is demonstrated with a computer simulation and experimental measurement, and compared with commercially available measurement devices. It is shown that the method provides sufficiently accurate results for many practical applications; therefore, it is appropriate for laboratory testing and for industrial applications.