Complete Interferometer System

Product Code: OS-9258B


No study of interferometry should overlook the historical importance of the Michelson interferometer. Yet in the laboratory, the Fabry-Perot and Twyman-Green interferometers can be more important tools: the first for high-resolution spectroscopy; the second for testing and producing optical components with aberrations that can be measured in fractions of a wavelength.

The PASCO Interferometer is a high-precision, movable-mirror interferometer that can be used to perform Michelson, Fabry-Perot, and Twyman-Green interferometry. The mirrors are attached with thumbscrews, so it’s easy to set up and change configurations.

The PASCO Interferometer can be ordered in a variety of systems. The Precision Interferometer can be operated in either the Michelson or Fabry-Perot modes. The Complete Interferometer Systems also contain components for the Twyman-Green mode and a vacuum pump for the refractive index of air experiment. The Systems Component List shows the contents of each system.


  • Stable: The massive (5 kg) base is machined from a single block of aluminum ensuring extremely stable optics.
  • Smooth Mirror Movement: With the taut-band suspension system, there’s no starting or stopping friction and virtually no backlash (less than 0.5 micron).
  • Precise Measurements: Mirror control is extremely fine: one micron per division of the micrometer head. The mirrors and beam-splitter are flat to 1/4 wavelength to ensure uniform interference patterns.
  • Larger Optics: The 3.2 cm (1-1/4″) diameter optics in the PASCO Interferometer produce larger and sharper interference patterns for better experimental results.
  • Complete: The Basic Interferometer includes everything necessary to perform basic Michelson and Fabry-Perot interferometry.


  • Perform basic Michelson and Fabry-Perot interferometry
  • Demonstrate that cross-polarized beams will not interfere
  • Measure lens irregularities in Twyman-Green Mode
  • Measure the indices of refraction for air and glass
  • Measure the indices of refraction for user-supplied materials

Typical Experiments

  • Introduction to Interferometry
  • The Index of Refraction of Air
  • The Index of Refraction of Glass

What’s Included

Support Documents

Precision Interferometer Manual English 648.91 KB
Laser Alignment Bench Manual English 53.02 KB
Mini Laser Adapter Kit Manual English 64.53 KB