Abstract
High-reflectivity coatings on micromirrors are critical to reduce reflection losses and absorptive heating. Unfortunately, coating stress induces an unwanted curvature in micromirrors. This effect is much more serious than in bulk optics because the thin coatings are similar in thickness to the structural material of the mirror. This paper describes a method to apply coatings that simultaneously achieve high reflectivity and optical flatness. The design theory is based on one-dimensional (1-D) static analysis and achieves curvature compensation with only a single additional coating layer The technique is appropriate for any number of coating layers and includes both the elastic and plastic behaviors of the thin film layers. Plastic deformation is modeled using an empirically determined strain versus dielectric thickness curve. Experimental measurements of 200 /spl mu/m/spl times/200 /spl mu/m/spl times/3.5 /spl mu/m polysilicon plates show mirror flatness better than /spl lambda//10.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
