Design, Fabrication, and Testing of an Adhesive-Free Mount for 330 mm Transmission Flat Optical Window

Abstract

The manufacturing and testing of optical components has been a mix between a science and an art for the better part of a few thousand years. From the early days of Galileo to the massive polishing laps underneath Arizona Stadium, the design, fabrication, and testing of optical components has contributed to many of the key scientific and technological advancements of humanity. One area that is constantly pushing the limits of optical fabrication, is fabrication for optical metrology equipment such as interferometers. The reference quality optics used in these instruments are pushing the limits of what is possible using traditional optical fabrication techniques such as pitch polishing. The optical substrate is often the most expensive and most critical single component in many systems. Another challenge that goes into the process of building reference quality optics is the need to mount the optic so it can be used with an optical system, such as an interferometer. The design and fabrication of both the mount and the substrate in parallel allows for a most optimal design that will encourage best post assembly performance of the substrate. The mount is an original design that will become a new product line for Precision Optical, a high precision planer components manufacturer located in Costa Mesa California. Design considerations include compensating for the effects of gravity inducing stress on the substrate, the stiffness of the mount, the likelihood of failure analyzed using finite element analysis (FEA) techniques, the best approach for securing the substrate in the mount, and the best fabrication approach for the manufacture of the substrate. Verification was performed using a Zygo ATZ© Fizeau Interferometer, with an 18” beam expander. An overview of the design process for the mount, the fabrication approach, and the verification data is provided. In addition, a large tip-tilt stage that was used in the testing process, but not directly a part of the project itself, was also designed and built. A general overview of the design of the stage is also discussed.