D7 Interferometer

Interferometry is the first choice of optical measuring method when it comes to measuring surfaces with high precision. With the D7 interferometer from Difrotec, we present a system that represents an innovative milestone in the field of interferometric measurement technology. A compact, user-friendly system with an accuracy that sets standards in the field of interferometry.

The D7 interferometer is a so-called PSPDI system (Phase Shifting Common Path Point Diffraction Interferometer). While the usual Fizeau interferometers require an optical reference, the D7 produces a perfect reference itself - a diffracted wavefront (generated by a sub-wavelength aperture in a thin metal film).

Typically, the D7 is used to test high-precision optics with complex shapes and large aspherical deviations. The system is supplied with DifroMetric software, which offers perfect analysis of the measurement results due to its multiple functions.

Technical details of the D7 interferometer:

Accuracy:< 0,6 nm (Lambda/1000)
Wavefront RMS Repeatability:< 0,23 nm (Lambda/2800)
Acquisition time:10 ms
Numerical Aperture:0,6 (F#0,83)
Numerical aperture of imaging system:0,55 (F#0,91)
Optical zoom:4-x
CCD camera500 x 500 Pixel
Height resolution:Lambda/8000
Laser:Stabilized HeNe, 632.8 nm (others upon request)
Performance:2 mW


Contact us...

Tel +49 (7271) 129900


If you provide us with your test sample, then we can measure it for you and discuss the results with you.

As a rule, we make measurements for one test sample free of charge.

If you would like to have several samples measured, we will be happy to provide you with a corresponding offer.

Usually, we do have a demo system available at out site in Germany.
This system can be easily used to demonstrate the general features and capabilities of these advanced systems.

A demonstration with your specific devices might depend on the respective configuration necessary for your measurement task.

Please contact us, we will be happy to discuss the possibilities with you.

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