There is a growing need to fabricate high-optical-quality optics that conform to an aircrafts outer moldline shape to reduce drag. However, fabrication of such free-form and aspheric optics has proven challenging. The current fabrication bottleneck is in the speed and precision of performing metrology of the optical surfaces because traditional interferometric techniques are not applicable. To meet the established technology and market gap, Bridger Photonics, Inc. proposes developing a length metrology system capable of interferometric-level precision, but with absolute length and thickness measurement capabilities (i.e. not merely displacement). Bridgers metrology system will be coupled with precise, multi-axis stages to rapidly scan and characterize free-form optical surfaces and thicknesses during or after fabrication. The system will be based on Bridgers proprietary high-resolution coherent measurement techniques and will achieve nanometer-scale precision, >1 kHz update rates, and up to 100 mm measurement ranges for specular surfaces. Because of the thickness measurement capabilities, Bridgers system will be capable of measuring the transmitted wavefront of large aspheric optics.
Benefit: The primary benefits of the proposed optical metrology system will be to dramatically increase manufacturing throughput, improve metrology precision, and reduce cost for large aspheric optics. Bridger anticipates that their product will reduce optical metrology time by more than a factor of ten compared to the current state-of-the-art. Bridgers solution is will also find application in calibration of metrology machines (CNC, CMM, AFM, SEM), wafer positioning and optic alignment for the semiconductor industry, and part mapping and positioning for laser materials processing applications.
Keywords: Thickness, Interferometry, optical fabrication, metrology, optical
