Chemical bonding for precision optical assemblies

We report on the optimization of precision optical component assemblies for space application with respect to mechanical resilience and retention of optical tolerances such as flatness and angles. Optimized parameters include: the cleaning method of the surfaces to be joined; type, concentration, and quantity of the chemical bonding agent; and post-bonding and curing conditions. Experimental studies and quality assurance are complicated by the large statistical spread in breaking stress, which requires the preparation of a large number of samples. The results previously reported in literature have focused primarily on fused silica, rather than space-qualifiable materials such as Zerodur (R) and ULE (R), and have typically addressed only one or two of the parameters. This study provides a comprehensive picture and a better general understanding of what makes a bond reliably strong. (c) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3533034]