Diffraction

  • Qualitative study of Fresnel diffraction (screen edge, slit, hair, etc.). Conditions for observing Fraunhofer diffraction.
  • Quantitative study of Fraunhofer diffractionpatterns through a slit or hole. Measurement of the intensity profile using a recording device ( Caliens CCD bar and computer interface, or mobile photocell connected to a computer via an acquisition card). Software programs allow the parameters to be adjusted in order to superimpose the theoretical curve and the experimental curve in both cases. Application to the measurement of the diameter of a hair and of lycopod pores.
  • Study of diffraction by a grating in monochromatic light.
  • Properties of Fourier transforms (Babinet's theorem, reciprocity). Application to filtering: Abbe's experiment, visualization of a phase object by strioscopy: glycerol drop falling into water (qualitative) or ultrasonic wave in a fluid (quantitative: measurement of acoustic wavelength, see note "Optics and acoustics").
  • Study of the resolving power of a lens with a slit diaphragm (Rayleigh criterion).
Published on March 13, 2017
Updated on March 13, 2017