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After a discussion of tolerable levels of instability, four types of dimensional instability are defined: thermal, temporal, cycling and hysteresis, with examples given for each. The principal causes of these instabilities: external stress, changes in internal stress, microstructural changes and inhomogeneity/anisotropy of properties, are explained in some detail along with a discussion of material types and properties. Most importantly, methods for minimizing the instabilities are shown. This discussion includes specific recommendations for commonly used materials including: processing techniques to minimize instability, specific problems observed in some materials and how to avoid the problems, and some general guidelines regarding the effects of fabrication methods on stability. It is most important to realize that increasingly tighter specifications for optical instruments mean that the optomechanical designer must work concurrently with other engineering disciplines, particularly materials and processes engineers, to insure the desired thermal and temporal stability of the product. |
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CITATIONS
Cited by 8 scholarly publications.
Optical components
Optical instrument design
Materials processing
Fabrication
Process engineering
