Interference and Diffraction

Product Code: EX-5645


Interference and diffraction patterns from laser light passing through various single-slits and multiple-slits are scanned and plotted in real time. These patterns are then examined for similarities and differences.

The distances between the central maximum and the diffraction minima for a single slit are measured by scanning the laser pattern with a Light Sensor and optical encoder built into the Wireless Diffraction Apparatus. Also, the distances between interference maxima for two or more slits are measured. These measurements are compared to theoretical values. Differences and similarities between interference and diffraction patterns are examined. In addition, the effect of the wavelength of the light is examined.

PASCO Advantage: Since the built-in optical encoder tracks the position of the Light Sensor, it is not necessary to move the Light Sensor at a constant speed. The Intensity vs. Distance graph is plotted in real time, showing the connection between the intensity pattern and the actual laser pattern.


  • Single-slit diffraction
  • Two-slit interference
  • Multiple-slit minor maxima
  • Effect of light wavelength on diffraction and interference patterns

What’s Included

  • 1x Wireless Diffraction Scanner (OS-8441)
  • 1x Diffraction Slits (OS-8442)
  • 1x Red Diode Laser (OS-8525A)
  • 1x Green Diode Laser (OS-8458B)
  • 1x Optics Track, 1.2. m (OS-8508)