Automated off-axis MTF and WFE polychromatic test bench

06 Oct 2015

Phasics latest measurement bench for lens quality control delivers wavefront error (WFE) and MTF at multiple wavelengths from 400 to 750 nm and through the whole field from -90° to + 90°. This comprehensive measurement is highly valuable to benchmark optics working in very variable conditions such as fisheye lenses used in assisted vision systems for automotive or in surveillance cameras. It also applies to any other lenses and assemblies of large numerical aperture up to F/1. This bench is fully automated for fast, easy and robust measurement that meets production imperatives.

Key features

• Accurate and complete comparison to design or to other lenses:
  • Off-axis MTF from -90° to + 90°
  • WFE in the exit pupil
  • Polychromatic test on the same compact bench: up to 12 wavelengths from 400 to 750 nm
• Fully automated:
  • High throughput
  • High repeatability: <0.5% MTF (ISO 5725) through the whole field

Detailed description:

The bench takes advantage of Phasics patented technology. Its exclusive configuration without relay lens significantly increases throughput and robustness by simplifying the alignment process. Full automation then warrants repeatable measurement.  The bench achieves the high repeatability of 0.5% for MTF through the whole field (as per ISO 5725 definition). The achromatic behavior and the high resolution of Phasics technology ensure accuracy through the whole visible spectrum.

This configuration is also a key asset for off-axis measurement analysis. Wavefront error and MTF at any field angle are provided in the lens exit pupil by applying a pioneering ray-trace algorithm to the measurement. This results in a straightforward comparison to optical design (Zemax, CodeV). It also allows accurate benchmark of third-party lenses.

This solution will be presented at the upcoming Optifab conference on Thursday morning during session 13: Metrology III in the talk: “Automated full-field range OPD and MTF measurement bench for automotive objective benchmark” (Paper 9633-66).

Phasics team will also be pleased to meet you on the booth #1101 or to discuss with you at any other time.

With this new bench, Phasics now offers a very large range of solutions (wavefront sensor from UV to far IR, opto-mechanical and software modules) dedicated to lens and assembly characterization. They can be smartly combined to build functional and robust measurement benches fitting each customer‘s application.