A simpler and lower cost Reactive Ion Figuring (RIF) process was demonstrated, combining with flexible film photomasks and an algorithm of masking layers distribution for less iteration. As a novel alternative figuring technology, RIF with parallel removal mode and chemical removal mechanism has showed the actual potential for large segment class figuring, especially in mass production of lightweight optical membrane components. Although diffractive membrane optics has been expected to meet the requirement of large aperture space-based telescopes, the flexible membrane has so different properties from traditional materials that the desired geometrical form is hardly obtained by current ultra-precision surface manufacturing technologies. In this paper, a 300 mm aperture polyimide membrane substrate was figure-corrected by RIF from the initial figure error of 62 nm rms to the final figure error of ~20 nm rms in total effective figuring time of ~4.3 minutes. Film photomask lowered the cost of photomask fabrication down to less than two hundredths of that of quartz photomask fabrication. All distributions of protected regions and removed regions, i.e., the patterns to be fabricated onto film photomasks, were obtained from the transmitted wave-front map just at the start of the entire RIF process. After 2 iterations, it took ~4.3 min to figure this sample and the 20 nm RMS is obtained with a RMS convergence ratio of 3.1.
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.