Aspheric Surface Figuring Using Plasma Assisted Chemical Etching

Aspheric Surface Figuring Using Plasma Assisted Chemical Etching Corning-OCA Applied Optics, Inc. Garden Grove, CA Innovation This SBIR project resulted in a rapid, automated, low-cost method for the figuring of precision aspheric surfaces on fused silica optical elements. Accomplishments l Corning-OCA established pre-processing methods and a suitable Plasma Assisted Chemical Etching (PACE) removal depth strategy for fused silica to ensure that final PACE-finished surfaces meet current low-scatter optical standards. l Corning-OCA developed an accurate model for the PACE process on fused silica to precisely optimize the plasma etching tool path over the substrate surface to produce the desired correction. l Corning-OCA also designed and built a second generation PACE system which meets the material and electrical compatibility requirements imposed by the plasma etching process and demonstrated the capabilities of the final one-step PACE figuring method on a fused silica test substrate. Commercialization l Lawrence Livermore National Laboratory has expressed a strong interest in PACE as a cost-effective fabrication technique for laser optics. l Norton Diamond Films, a primary player in the diamond coating market, has expressed interest in PACE’s figuring capability. Marshall Space Flight Center Date of Update: 3/27/98 Success Story #: 8 -005 Corning-OCA PACE Aspheric Figuring System Government/Science Applications l Potential applications include silicon aspheric figuring; ultra-low scatter surfaces; silicon clad silicon carbide components; optical elements requiring zero subsurface damage; diamond thinning and figuring; and complex oxide thinning and figuring. l The basic methodology developed during this program can be readily optimized for additional materials, including silicon, germanium and others. Points of Contact: - NASA (Denise Swain; 256/544 -8112) - Corning-OCA Applied Optics (Steve Hoskins; 714/895 -1667) 1990 SBIR Phase 2; NAS 8 -39374