Abstract: A technique is disclosed for achieving critical alignment of optical and mechanical elements, in which one of the foregoing is movable with respect to the other. Specifically, an optical fiber (12) is aligned with respect to a movable member (19) in a first position. The movable member is then displaced to a second position and high levels of radiant energy at a first discernible wavelength are transmitted down the fiber optic path to alter, or pattern, a wavelength sensitive surface area or coating (16) on the surface of the movable member. The movable member is then freed, and radiant energy of a second wavelength to which the coating is insensitive is used to sense the position of the movable member with respect to the fiber optic.

Abstract: Vibrating resonant mechanical structures are excited optically by photokinetic energy transfer and detected optically. In particular, a tuning fork sensor measuring a physical parameter is excited into oscillation by radiant energy and the frequency of vibration is detected by radiant energy which may be communicated via an optical fiber. These vibrations are communicated via a fiber optic to a detection location.