Martin Ross-Messemer

Controlled diffraction using smart materials

By introducing sinusoidal deformations on piezoelectric crystals using surface acoustic waves with spatial frequencies > 30 mm-1 and amplitudes > 1 nm new optical diffractive elements can be generated. For high diffraction efficiencies it is necessary to produce amplitudes of the SAW as high as possible or to use light wavelength as short as possible. Conventional diffraction gratings are fixed in amplitude and spatial frequency whereas both can be varied for this new type of gratings. The gratings can operate in several environments such as N2, He gas or vacuum and be remote controlled. Therefore they are a very flexible tool. First results on these gratings with frequencies up to 200 MHz and amplitudes in the order of 5 nm are shown.