| abstract |
The focusing properties of a traveling elastic wave are employed to convert a low-resolution input light beam into a high resolution output beam, both beams scanning linearly in synchronism with the phase velocity of the elastic wave. The elastic wave can be a dilational wave in a transparent solid or liquid of, for example, acoustic character, or a flexural wave on a thin reflector. Specifically, scanning optical beam is projected through appropriate optics to focus on the input plane of the traveling-wave dynamic lens in such a way as to scan transversely at the velocity of a traveling acoustic wave. The acoustic wave is phased such that the instantaneous axis of symmetry of the traveling lens coincides with the optical axis of the scanning input beam, and this relationship is maintained throughout the duration of the line scan. The size of the input spot is restricted to cover a total of approximately one-fourth of an acoustic wavelength, in order to avoid aberrations in the dynamic lens. |