4D Technology, a wholly owned subsidiary of Onto Innovation Inc., shipped an AccuFiz® D with a 600 mm (24 inch) beam expander. It is the industry’s first and lightest on-axis dynamic interferometer with a 24” aperture. The beam expander offers high quality measurement of optics up to 600 mm in diameter, with excellent stability and thermal behavior. Based on 4D Technology’s patented dynamic interferometry, proven to measure remote cavities, optical thickness, and homogeneity, even in the most challenging environments. The single frame acquisition method provides vibration immunity and it also mitigates turbulence-caused phase errors by averaging them out from measurements.
Isolating large optical systems from vibration is a difficult challenge and normally requires large and costly isolation tables. By using dynamic measurements, vibrational coupling and turbulence in a large cavity measurement are not an issue. On-Axis Fizeau measurements avoid the retrace error induced when using spatial carrier dynamic techniques, improving performance.
The AccuFiz D mainframe interferometer features a low-coherence laser to separate the signals from parallel surfaces in an optical system under test. This configuration permits measurement of front and back surfaces of plane-parallel optics. The system is therefore capable of measuring transparent semiconductor substrates, windows, and the kinds of domes used for covering aerospace imaging systems—down to less than 200µm thickness.
This innovative interferometer was created with performance and versatility in mind. AccuFiz D interferometer’s ultra-light build and kinematic mounting enables the user to remove it from the beam expander and to replace it without the need for re-alignment. This makes stand-alone operations with the 100 mm mainframe fast and easy.
The 600mm reference flat optical mounts are low stress, and provide highly repeatable tip and tilt of the reference optics. The vibration immune performance allows large optical components to be mounted on separate tables.
The AccuFiz D 600 mm package incorporates 4Sight™ Focus, a 64-bit multithreaded software platform that provides a clear, simplified interface and blazing fast analysis. New functionality in the software includes enhanced masking, a powerful built-in database, and the technology for acquiring and manipulating large numbers of measurements very quickly.
The new AccuFiz D 600 mm system, combined with the 4Sight Focus analysis software, upholds 4D Technology’s tradition of offering high-performing interferometers while providing industry-leading service and applications support.
About 4D Technology
4D Technology is an Onto Innovation subsidiary and is a world leader in dynamic and high precision three-dimensional surface metrology.