There is a growing need to fabricate visibly-opaque, infrared-transparent, high-optical-quality optics that conform to an aircrafts outer moldline shape to reduce drag. However, fabrication of such free-form and aspheric infrared (IR) optics has proven challenging. The current fabrication bottleneck is in the speed and precision of measuring the optical figure and transmitted wavefront error for these IR optics. To meet the established technology and market gap, Bridger Photonics, Inc. proposes developing a length metrology system capable of measuring absolute length and thickness at an IR wavelength that transmits more efficiently through the critical IR materials. Bridgers metrology system will be coupled with precise, multi-axis stages to rapidly scan and characterize free-form IR optical surfaces and thicknesses during and/or after fabrication. The system will be based on Bridgers proprietary high-resolution coherent measurement techniques and will achieve 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 error of these IR 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 IR 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 will also find application in other markets where thickness of IR transmitting ceramics is required.
Keywords: Infrared, optical fabrication, optical, Thickness, Interferometry, metrology
