Laser-induced damage (LID) tests were conducted on CaF2 optics at 193 nm using ISO S-on-1 method with the S varying from a standard 200 to 103, 104, and 105 shots/site and fluences ranging from 0.1 J/cm2 to 4.0 J/cm2. Using a flat-top beam profile and a beam footprint of 250 μm × 250 μm, absorption-derived LID was observed on the standard 200-on-1 test. Defect-initiated LID was detected by increasing the pulse count with a reduced fluence. The absorption-driven LID was attribute to subsurface damage and two-photon absorption. The former was eliminated by using a FemtoFinish polishing process. The latter was experimentally determined by using laser calorimetric measurement. Improved crystal bulk and surface finishing quality were confirmed by X-ray diffraction and laser calorimetric measurement. Accelerated lifetime damage test (ALDT) was further conducted with an increased pulse count up to 106 shots/site. The results confirm an enhanced lifespan prediction of the demanding laser optics.
This paper describes the manufacturing steps necessary to manufacture hemispherical concave aspheric mirrors for high- NA systems. The process chain is considered from generation to final figuring and includes metrology testing during the various manufacturing steps. Corning Incorporated has developed this process by taking advantage of recent advances in commercially available Satisloh and QED Technologies equipment. Results are presented on a 100 mm concave radius nearly hemispherical (NA = 0.94) fused silica sphere with a better than 5 nm RMS figure. Part interferometric metrology was obtained on a QED stitching interferometer. Final figure was made possible by the implementation of a high-NA rotational MRF mode recently developed by QED Technologies which is used at Corning Incorporated for production. We also present results from a 75 mm concave radius (NA = 0.88) Corning ULE sphere that was produced using sub-aperture tools from generation to final figuring. This part demonstrates the production chain from blank to finished optics for high-NA concave asphere.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.