Phase Interferometer
1550 nM / 635 nM

  Fizeau Interferometers

  Other Dual Wavelength

  Infrared Interferometers

  Grazing Incidence

  Why Grazing Incidence?

  How Phase Works

  Advantages of Dual 
  Wavelength Interferometers



The Model 155irVIS is one of our new Phase-shifting Fizeau Interferometers that operates in two modes: Infrared or Visible—switch selectable. The instrument features a fused silica collimator. Two separate lasers are employed – a single mode diode laser operating at 1550 nM and single mode diode laser operating at 635 nm.  Both sources are dithered to produce speckle-free live images on the computer monitor.  Two cameras are used – one with sensitivity at 1550 nM; the other is used for the visible.  The infrared camera provides a resolution of 320 x 256 pixels. The visible wavelength camera provide resolution of  768 x 494 pixels.

The Model 155irVIS utilizes EndoPhazeTM for hysteresis-free phase shifting together with Durango Universal Interferometry Software to allow the operator to achieve highly accurate and repeatable measurements at both infrared and visible wavelengths. 

In typical usage of a Dual Wavelength Interferometer, the operator can align the optical system and perform any necessary tip/tilt operations with the interferometer in VISIBLE MODE — greatly simplifying the procedure.  Measurement of reflective surfaces can also be measured at 635 nm – providing higher accuracy. 

A remote control box permits adjustment of Zoom and Focus as well as controlling Iris diameter and Illumination Intensity.  This control operates at both 635 nm and 1550 nm wavelengths. The Model 155irVIS is equipped with a 2.2 GHz All-in-One Computer for high speed and smaller footprint.

Dual Wavelength 1550 nM / 635 nM switch selectable. Two wavelength optical paths are coaxial
4-inch aperture  Ideal for test pieces from 1/2 to 4 inch diameter
Tip / Tilt plate with standard bayonet mounting for Transmission flats or Transmission spheres Transmission flat (1/20 wave at 635 nm) provided.
Transmission spheres and pellicles available.
ZOOM Lens 4X for both wavelengths Remote controlled for hands-off operation.
Rugged construction High mechanical stability
A Turnkey System User Friendly and ready to go
Two spot alignment For quick setup on each new part tested.  Setup of test piece at either wavelength is aligned at both wavelengths
Dithered Laser sources at 1550 nM and 635 nM Sharp Speckle-free interferogram at both wavelengths
EndoPhazeTM Frequency-Shifting For smooth hysteresis-free phase measurement
635 nm CCD camera Resolution 768 x 494 pixels
1550 nm Camera Resolution 320 x 256 pixels
Higher resolution camera available
Windows environment
PV and rms in users choice of units
High level of repeatability
Excellent reproducibility
Large choice of graphic displays
Dynamic Sections
3-D OPD Plot
Reference Subtraction
MTF and PSF graphics and plots
Zernike Polynomials available for all measurements
Seidel Coefficients available
2.2  GHz All-in-One Computer  For high speed data reduction with smaller footprint
Live interferogram on computer screen For easy viewing -- no video monitor required
1/50 wave at 1550 nM, 
1/20 wave at 632.8 nM
High Accuracy 
Repeatability 1/300 wave PV,  1/1000 wave rms
Reproducibility Excellent
Data acquisition Time 30 milliseconds (typical)
Data reduction time  ~3 seconds (typical)
Dimensions (L x W x H) 20 x 18 x 10 (inches) Small footprint
Weight 75 pounds (34 kg) approximately Solidly built for high stability
Manual Illustrated Operator's Manual
Power  117/240 Volts  60/50 Hz Wired with proper plug for user's power system
Warranty Standard one-year limited warranty against defective components or workmanship
For Further Information, call Gordon Graham today at (818) 700-1263  E-Mail:
Graham Optical Systems,   9530 Topanga Canyon Blvd.,   Chatsworth, CA 91311
Copyright © 2014 Graham Optical Systems  All Rights Reserved
*Durango is a trademark of Diffraction International   EndoPhazeTM  is a trademark of Graham Optical Systems
This page last updated July 15, 2014