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Zygo Transmission Spheres

Zygo offer a complete range of high quality transmission spheres (TS) designed to provide optimum interferometer performance. Zygo’s optics are specified and fully qualified to ensure accurate metrology for applications ranging from testing conventionally polished ultra smooth surfaces, to providing critical metrology feedback for small tool polishing processes. Each Transmission Sphere comes in a protective storage case with quality certification.

OVERVIEW - Measurement Capability

Zygo Transmission Spheres are used in conjunction with a laser Fizeau interferometer for the measurement of the surface form or transmitted wavefront of spherical optics and assemblies. They can also be utilized in the measurement of conic and aspheric shapes using the unique capabilities of the Zygo VeriFire Asphere interferometer.

The range of Transmission Spheres is available with Entrance Beam Diameters (Interferometer Aperture Size) of 25 mm, 4 inch, 6 inch. They are designed for use at a wavelength of 633 nm and have low expansion reference elements.

The field coverage and residual axial ghosts are suitable for use with Zygo Ring-of-Fire illumination as used in the high-end Verifire AT+ interferometer based systems. Controlled mid-spatial frequency content (PSD) make them suitable for use in closed-loop feedback processes in work cells utilizing small pad polishing technologies.

STANDARD PERFORMANCE (λ/10)

Transmission Spheres have a Reference Surface reflectivity of 4%. This makes them best for metrology of test optics with ≤ 40% reflectivity.

The following apertures and f/numbers are available for λ/10 PV (λ = 633 nm) accuracy.

Aperture f/number
25 mm f/0.58, f/0.7, f/1.0 (use with VeriFire AT+ based systems)
4 inch (101.6 mm) f/0.65, f/0.75, f/1.5, f/3.3, f/7.1, and f/10.7
6 inch (152.4 mm) f/0.8, f/1.1, f/2.2, f/3.5, f/5.4, and f/7.2

STANDARD PERFORMANCE DYNAFLECT (λ/10)

Transmission Spheres have a Dynaflect™ coated Reference Surface. This makes them best for metrology of test optics with > 40% reflectivity.

They are available for 4 inch (101.6 mm) aperture systems with f/0.75, f/1.5, f/3.3, f/7.1 and f/10.7 f/numbers with λ/10 PV (λ = 633 nm) accuracy.

HIGH PERFORMANCE (λ/20)

Transmission Spheres have a Reference Surface reflectivity of 4%. This makes them best for metrology of test optics with = 40% reflectivity.

They are available for 4 inch (101.6 mm) aperture systems with f/0.65, f/0.75, f/1.5, f/3.3, f/7.1 and f/10.7 f/numbers with λ/20 PV (λ = 633 nm) accuracy.

ULTRASPHERE (λ/50) Transmission Sphere

The NEW Zygo UltraSphere product is designed to enable surface form metrology with an uncertainty in the RMS (2) of ≤ 3.2 nm (λ/200 at 633nm) when used with a Zygo interferometer.

They have a Reference Surface reflectivity of 4% and are best for metrology of test optics with ≤ 40% reflectivity.

They are available in 4 inch (101.6 mm) diameters with f/numbers of f/0.75, f/1.5 and f/3.3 with λ/50 PVr (λ = 633 nm) accuracy.

The UltraSphere (λ/50) Transmission Spheres are specified as having a PVr of λ/50 (λ = 633 nm). (PVr is defined as the 36 term Zernike fit plus 3 times the rms residual of the Zernike fit). Also, the Transmitted Wavefront Slope supports < 2 nm RMS cavity induced error.

The UltraSphere TS products include absolute calibration of the reference surface and are shipped with the resulting MetroPro *.dat file and 37 term Zernike fit on a USB memory stick.



Click here to download the new and updated Zygo Transmission Spheres datasheet.