Vibration Insensitive Interferometer – MarSurf FI 3100 VB

Simultaneous Phase-Shifting for Vibration & Turbulent Environments


The MarSurf FI 3100 VB Simultaneous Phase-Shifting Fizeau Interferometer is a real-time, high-speed, truly vibration-insensitive metrology instrument with shutter speeds as fast as 10µs. Ideally suited for shop/production floors and other vibration or turbulent environments, the MarSurf FI 3100 VB offers unsurpassed measurement versatility, stability and repeatability for measuring and analyzing optical, machined, and semiconductor wafer surfaces.

Data Sheet (PDF)

Overview (PDF)

Setup Guide (PDF)

MarSurf FI 3100 VB with Auto-SPARC

All polarization based, vibration insensitive interferometers are in essence, dual beam interferometers. This is so because they use orthogonally polarized test and reference beams to achieve simultaneous phase-shifting. Therefore, birefringence (natural or stress induced) in the optical system of the interferometer, or transmission optic, will introduce changes in phase between the P- and S-polarized beams which will result in measurement errors. However, the unique design of the MarSurf FI 3100 VB, coupled with Auto-SPARC, allows Mahr-ESDI to overcome and eliminate these errors. With Auto-SPARC, the MarSurf FI 3100 VB has been demonstrated to have instrument errors of less than Λ/100 with no vibration isolation. The MarSurf FI 3100 VB is indeed a dual beam interferometer but unlike similar systems, the MarSurf FI VB has no competition in its overall performance capability.


  • Measure flat, concave & convex surfaces, small to astronomical size
  • Long optical path length and remote Fizeau cavity measurements
  • Vacuum/cryogenic chamber measurements
  • In-situ measurements of optical, machined & wafer surfaces
  • Dynamic measurements for thermodynamic events, rotating discs, etc.
  • Characterization & removal of birefringence effects


  • Absolute vibration insensitivity
  • Common path Fizeau geometry
  • Measure surfaces with 0.1% to 100% reflectivity
  • Automated stress measurement
  • Remote Fizeau cavity & long optical path applications
  • 10µs exposure times
  • True 1k x 1k resolution, fringe densities equivalent to ≥250 fringes of tilt
  • Uses Industry Standard 100 mm (4″) bayonet reference optics


how it worksSimultaneous phase-shifting is accomplished by utilizing polarization to achieve the phase-shift and by replacing the standard camera with Mahr-ESDI’s patented HyperPhase™ Module. The module uses three sub-pixel aligned cameras, which are monolithically bonded together with the beam splitting and polarization optics into a small, robust package. The result is a highly reliable and accurate camera system with a lifetime alignment warranty. The advantage of using three cameras is that each of the interferograms retains the true resolution of the camera.