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Zygo Mini Optimized for Production Metrology

1 May 2012

Zygo Mini

The Zygo Mini is a compact self-contained interferometer system, designed to meet the unique requirements of production metrology.

Key Features:
  • Reliable metrology in production environments
  • Quantitative results without vibration isolation
  • Intuitive touch-screen operation
  • Simple pass/fail notification
  • Secure supervisor set-up
  • Zoom to 4X
  • Correlation to industry standard

With its simple touch-screen user interface, the Zygo Mini virtually eliminates operator variability that often plagues basic methods of interferogram interpretation. In addition, the quantitative results enable the user to optimize production process control by recording manufacturing trends, without affecting throughput.

The streamlined user interface, combined with proprietary acquisition techniques, make the Zygo Mini easy to operate in most production environments – without vibration isolation.

The state of the art electronics, robust operation, and optimized packaging make the Zygo Mini the ideal solution for production metrology.

Zygo Mini brochure


The peak-to-valley (PV) specification - is there a better way?

7 May 2009


For measurements made by Laser Fizeau Interferometers PV is frequently increased erroneously by outliers and artefacts of the measurement which the metrologist is confident are not associated with the surface under test. Methods for removing those outliers from the measurement result are not standardized.

Introducing PVr

Understanding the PV Specification download
PVr A Robust Amplitude Parameter download

PVr is a newly defined parameter pioneered by C. Evans of Zygo Corporation that is related to imaging and is robust over a range of instruments.

Briefly, PVr for circular apertures is defined as:

PVr = PV36 Zernikes + 3 x δ36 Zernike Resid



What Makes PVr Robust?

PVr is detector independent and reasonably insensitive to noise, specifically from small defects. By describing the surface via its Power Spectral Density function and then applying a 36 term Zernike fit, the underlying, low order, optical surface figure is captured. This represents the bulk of the surface amplitude.

The table shows the relationship of detector resolution to PV and PVr for a 300 mm flat optic. It shows the effect of reducing pixel resolution computationally on PV and PVr. Note the stability of the PVr value as the detector resolution is changed.

Detector Resolution PV, nm PVr, nm
1024x1024 53.81 39.46
512x512 38.27 39.41
256x256 36.88 39.33
128x128 33.9 39.19

To summarise, PVr is a Robust Amplitude Parameter with the following attributes

  • It is a repeatable method for specifying optical surfaces
  • It has low sensitivity to noise and detector resolution
  • The PVr application is available in MetroPro™ 8.3 or higher
  • It reduces instrument to instrument variability

Zygo Transmission Spheres

29 July 2008

Zygo Transmission Sphere

Zygo Corporation have introduced the NEW UltraSphere (λ/50) Transmission Sphere to enhance its range of transmission spheres for its laser Fizeau interferometer systems.

The range includes:

Standard Performance (λ/10) Transmission Spheres in 25mm, 4 inch and 6 inch Entrance Beam Diameters (interferometer apertures).

Standard Performance DynaFlect™ (λ/10) Transmission Spheres in 4 inch Entrance Beam Diameter (interferometer aperture).

DynaFlect Coated Transmission Spheres are best for metrology of test optics with > 40% reflectivity.

High Performance (λ/20) Transmission Spheres in 4 inch Entrance Beam Diameter (interferometer aperture).

The new Zygo UltraSphere (λ/50) Transmission Sphere product is designed to enable surface form metrology with an uncertainty in the RMS) of ≤ 3.2 nm (λ/200 at 633nm) when used with a Zygo interferometer. The UltraSphere is an uncoated transmission sphere. Like the Standard and High Performance transmission spheres, the UltraSphere range is best for metrology of test optics with ≤ 40% reflectivity.

The new Zygo UltraSphere (λ/50) is available in 4 inch aperture size with f/numbers of f/0.75, f/1.5 and f/3.3.

Click here for more information