Non-Destructive Testing System Based on Bacteriorhodopsin Films

T. Juchem and N. Hampp

Institute of Physical Chemistry, Philipps-University, Hans-Meerwein-St., D-35043 Marburg, Germany


The use of bacteriorhodopsin (BR) films as optical recording media in a system for holographic interferometry is reported. Because of the photoerasability of the BR films no consumables are required. The system is capable to operate in a variety of interferometric techniques like double-exposure, time-averaging and real-time interferometry. An additional feature of the system is the implemented phase shift analysis. This enhances the resolution of deformation analysis down to l/100 (ca. 5 nm). Bacteriorhodopsin films with an free aperture of 90 x 90 mm enable high resolution lensless recording (5000 lines/mm). The holograms are recorded in a homodyne reflection type geometry. The laser used in the system for recording is a frequency doubled Nd:YVO4 laser, which delivers 2 W at 532 nm. Photochemical erasure is done with by incoherent blue light. An adjustable and zoomable lens in front of the systems CCD camera enhances the optical readout resolution. The system is controlled completely by software. Some typical application examples like the bending of ceramic motor valves made from silicone nitride are demonstrated. A short video film on the general function and operational modes of the system will be presented.