Title of Presentation: Stable Materials and Bonding Techniques for Space-Based Optical Systems
Primary (Corresponding) Author: Alix Preston,
Organization of Primary Author:
Co-Authors: Benjamin Balaban, Gabriel T. Boothe, Guido Mueller
Abstract: Advances in material science have expanded the list of materials and bonding techniques available that can be used to design complex structures with exceptional quality and reliability for use in space-based missions such as LISA, TPF, SIM, BBO, or the GRACE follow-on mission. These missions require complex optical systems made from materials and bonding techniques that must meet unprecedented dimensional stability requirements. In some cases, the intrinsic dimensional stability needs to be better than 100 fm/√Hz at Fourier frequencies as low as 0.1 mHz, or maintain a relative length stability less than 1 ppm over the lifetime of the mission. While there are materials that are thought to meet these requirements, few have been tested to these demanding levels. We present preliminary results on the dimensional stability of Zerodur, Silicon Carbide, and Super Invar at sub-pm levels, sufficient for most in-band applications. In addition, these missions rely on bonding techniques to assemble structures such as the telescope or optical bench. A new technique know as hydroxide bonding was originally developed for glass-glass bonds for the GBP mission, but has since been applied to other materials such as Zerodur, Silicon Carbide, and Super Invar. We will also report on first bonding strength measurements of hydroxide bonding between various materials and compare the dimensional stability of these bonds with the stability of optical contacts. This work is supported by NASA/OSS grant APRA04-0095-0007.