"Grazing Incidence Interferometer


  Why Grazing Incidence?


  Fizeau Interferometers

  Infrared Interferometers



The Model 2GRP LAZER GRAZER is a non-contacting Grazing Incidence Interferometer. . . the first modestly priced Interferometer for measuring flatness of semi-matte or matte-finished surfaces. The Model 2GRP also permits the measurement of parts which are much larger than its 2-inch aperture because it measures flatness across a 2 inch by 8 inch elliptical beam path as illustrated below.

Principle of Operation
When a rough surface is examined at a low grazing angle, it appears to be highly reflective. 

The LAZER GRAZER utilizes this principle to produce high contrast interferograms of unpolished surfaces.  A grazing angle of 14.48 degrees was selected since at that angle, each interference fringe equals one wavelength.  With a normal incidence Fizeau Interferometer, each fringe equals one half wavelength. Clicking on the link below will provide further information on the subject of Grazing Incidence Interferometers

The LAZER GRAZER is also available in this Open Top Format.Although, in a double-pass grazing system we trade-off some sensitivity for the capability of measuring unpolished parts, one wavelength per fringe is more than adequate sensitivity for such parts. 

The original format shown above provides a smaller footprint, but otherwise performs the same as the new low profile model shown at the right.

The low profile, open top model, 2GRPL is designed to facilitate automated test piece positioning. Either model is certain to provide you with the most economical solution to the problem of measuring flatness of unpolished parts

Low Profile LAZER GRAZER Model 2GRP

 All of our 2-inch aperture LAZER GRAZER Interferometers operate under the control of Durango Interferometry Software which provides a live interferogram on the computer screen.  The user can select from a rich palette of graphics, text files and reports.  For further Information click on Durango.
A typical LAZER GRAZER screen as produced by Durango Software.

A typical Durango screen,at the left, shows live interferogram, histogram, and OPD plot. Durango permits the user to select from a wide array of graphics, text files and customized reports. Note that the live image shows interference fringes on the surface of the test sample while providing a 3-D image of the part. This unique display is a feature available only with GRAHAM's Grazing Incidence Interferometers!  This capability is of enormous value in the interpretation of test pieces with complex geometry..

Grazing Incidence Interferometer Measures matte, semi-matte, and polished surfaces
Rugged Construction For high stability even in vibration areas
2-inch aperture (50.8 mm) Measures a 2-inch swath across an 8-inch test piece
1/20 wave fused silica reference surface High accuracy
Single Mode Diode Laser source  Dithered for Sharp, speckle-free images
No video monitor required Live interferogram on computer screen
Pupil imaging: continuous zoom (4x) Permits measurement of samples as small as 5 mm
Remote control Focus, Zoom, Iris,  Mode:  ALIGN / VIEW
Sturdy Integral Tip/Tilt Table Fine adjustment for easy adjustment
Adjustable height to accommodate thick samples
Two Spot Alignment For easy alignment of Tip/Tilt
EndoPhazeTM Phase Shifter For smooth hysteresis-free operation
CCD Camera Selected for highest resolution and maximum data capture at minimum cost
Durango Universal Interferometry Software For high repeatability
For high reproducibility
For high speed data reduction
For excellent colorful graphics
2.41 GHz All-inOne computer with 19.45 inch diagonal screen Interferometry Software, Image Acquisition Board, Data Acquisition Board all installed and configured for the Model 2GRP
Power Requirements  117 Volts 60 Hz or 240 Volts 50 Hz
Small Footprint Lower cost than competitive technology
Semi-Customized Choice of wavelength and CCD camera resolution
2GRP 635 nm  (Visible)
768 x 484 pixels
 Polished to Semi-matte
2GRP850 850 nm  (NIR)
768 x 494 pixels
Semi-matte to Matte
2GRP1550 1550 nm  (SWIR)
320 x 256 pixels
Other Wavelengths and Camera resolutions available.  Please enquire
To learn how Grazing Incidence works as well as more about our LAZER GRAZER Interferometers click on
For Further Information, Prices, Delivery, call Gordon Graham today at 
(818) 700-1263 or send an email to:
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 12, 2016