ANALYSIS, TEST AND MEASUREMENT
PLu apex non-contact 2D optical profiling system
6 January 2011
Sensofar-Tech (Terrassa, Spain) has introduced its PLu apex non-contact 2D optical profiling system, designed for measuring any optical surface, including aspheric and free-form optics. The design of the PLu apex is based on Sensofar’s core confocal profilometry technology, a technique that utilises the company's confocal tracking algorithm.
Confocal tracking uses structured illumination and a high numerical aperture microscope objective to determine the position of the sample surface automatically and precisely. By using a high-resolution air-bearing stage to track horizontal movement of the objective, and by collating this with the vertical position of the sensor head required to keep the surface in focus, the surface profile can be reconstructed with very high accuracy and reproducibility. The system offers a horizontal resolution of 1nm and a vertical resolution of 0.5nm, as well as a range of measurement objectives spanning 10 to 100x, quick and easy alignment of the sample, fast measurement across the sample (1mm/s typical) and the ability to measure up to 65° slope angles. The measurement ranges cover 0.1 to 100mm in the horizontal (500mm optional) and up to 50mm on the vertical axis.
The company's SensoTrack software provides a user-friendly interface, simplifying sample measurement, and a basic set of tools for displaying and analysing data. It also assists the user when aligning the sample for measurement. A powerful aspheric analysis module provides form assessment with respect to a design or a reference form.
The device is suitable for characterising high-volume mass production optics for commercial applications (blue-ray & DVD, mobile telephones, digital cameras and projector lenses), but is also well suited for high-precision lens and free-form optics designs as used in astronomical instrumentation, leading-edge optical data storage and photolithography.