AccuFiz Duo Fizeau interferometer

4D Technology Introduces AccuFiz® Duo Fizeau Interferometer

High precision, dynamic interferometer combines long and short coherence capabilities into one system for measuring an expanded range of optics.

AccuFiz Duo Fizeau interferometer

AccuFiz Duo Fizeau interferometer


Tucson, AZ, April 30, 2024 - 4D Technology, a subsidiary of Onto Innovation, announced today the launch of the AccuFiz Duo Fizeau interferometer.

The AccuFiz Duo dynamic interferometer uniquely combines the industry leading AccuFiz D short coherence capabilities with long coherence capabilities into a single system.

The AccuFiz Duo’s short coherence mode employs the same patented technology as the AccuFiz D, enabling vibration insensitive, on-axis, dynamic measurement for high accuracy measurement of optical grade surfaces. With a short coherence length source, the AccuFiz Duo measures flats and lenses without the need for coating surfaces to attenuate extraneous interference fringes. This mode enables surface error, transmitted wavefront error, remote cavity, wedge, optical thickness, and homogeneity measurements of plane parallel transparent surfaces down to 0.2mm thick.

The AccuFiz Duo’s additional long coherence source uses a stabilized HeNe laser and operates with all the benefits of a standard phase shifting Fizeau interferometer. The long coherence mode enables very long cavity measurements and has spatial carrier dynamic mode as an option for vibration and turbulence mitigation. It is also useful for standard radius of curvature measurements. The 632.8nm HeNe source facilitates measurements with digital holograms as well.

“We are excited to introduce this new offering to the optics community,” said Erik Novak, Vice President and General Manager of 4D Technology. “The AccuFiz Duo provides customers who are challenged with vibration and turbulence with a novel and modular dynamic system to enable them to measure a broader range of optics in a single system, saving on space and cost.”

The AccuFiz Duo has the same compact, lightweight design of the AccuFiz D, with 2 source modules to enable measurements on a broader range of optics in a lab or shop floor.

4D Technology’s user-friendly 4Sight Focus analysis software is common to both modes. 2D and 3D displays, filtering, and masking tools make it simple to quantify key surface shape; and Zernike, Seidel, geometric and diffraction analyses are all easy to perform.

The new AccuFiz Duo laser interferometer continues 4D Technology’s tradition of offering some of the world’s highest-performing interferometers, backed by industry-leading service and applications support.

About 4D Technology
4D Technology, an Onto Innovation subsidiary, is a global leader in dynamic and high-precision three-dimensional surface metrology with its vibration-insensitive, portable, and automated dynamic laser interferometers, optical profilers, and optical surface gauges. Our systems provide precise measurement of surface features, roughness, and defects — even in the most challenging environments. Serving: precision machined surfaces, optics, astronomy, aerospace and defense, space-based telescopes, optical communications, automotive, and in-line production measurements. Additional information can be found at

About Onto Innovation
Onto Innovation is a leader in process control, combining global scale with an expanded portfolio of leading-edge technologies that include: Un-patterned wafer quality; 3D metrology spanning chip features from nanometer scale transistors to large die interconnects; macro defect inspection of wafers and packages; metal interconnect composition; factory analytics; and lithography for advanced semiconductor packaging. Our breadth of offerings across the entire semiconductor value chain combined with our connected thinking approach results in a unique perspective to help solve our customers’ most difficult yield, device performance, quality, and reliability issues. Onto Innovation strives to optimize customers’ critical path of progress by making them smarter, faster and more efficient. With headquarters and manufacturing in the U.S., Onto Innovation supports customers with a worldwide sales and service organization. Additional information can be found at

Development Category (English)728x90