Total Error Freeforms

The Challenge

Being able to make precision freeforms not only with irregularity but also with being able to know where that surface is in respect to a global coordinate system.

Solution Delivered

Our solution to the requirement of total error freeforms is to drive for greater precision, both in alignment and final testing. Spherical optics can be readily corrected using interferometry, but freeform optics are more challenging. It is extremely difficult to align a freeform and maintain its coordination to a global system. The Optimax research and development team developed a process to use a coordinate measuring machine geared specifically towards surface profiling with higher resolution surface measurements, including (stitching, CGH, high-resolution profilometry, or UA3P).

Engineered Solutions in Action

SMOOTHING MID-SPATIAL FREQUENCY (MSF) ERRORS ON FREEFORM OPTICS WITH AN ALGORITHM-BASED ROBOTIC PLATFORM UTILIZING DEFLECTOMETRY INPUT

Freeform optics offer great flexibility in design parameters, but the subaperture techniques required for manufacture often result in mid-spatial frequency (MSF) errors that can impact final performance. These errors must be removed, but the options to do so, often requiring hand-smoothing by a skilled artisan, are costly and time-consuming. Optimax has developed the HERMES (High End Robotic MSF Elimination System) a robotic platform that uses a machine learning algorithm to smooth parts.

Learn from Our Experts

Measurement of mid-spatial frequency errors on freeform optics using deflectometry

Freeform optics have emerged as a new tool for optical designers and integrators. Manufacturing innovations are gradually increasing availability of precision freeform optics. As optics manufacturers strive to improve quality and decrease cost, some focus is placed on improvements in the challenging metrology requirements for freeforms. One relevant technique to be discussed here is the use of deflectometry to measure mid-spatial frequency error in-process or in-situ during the manufacturing of freeform parts.