Nanoholography

The paper deals with optical nano-holography. The observed objects are sodium-chloride nano-crystals and polystyrene nano-spheres illuminated by evanescent wave-fronts. The crystals and the nano-spheres become self-luminous objects producing pseudo-non-diffracting wave-fronts. The wave-fronts emerging from the crystals and nano-spheres are the result of electromagnetic resonances. A microscope is utilized to register the wave-fronts generated by the crystals and nano-spheres. A 6 m spherical particle made of polystyrene acts as a relay lens to collect the wave-fronts that are recorded by a monochromatic CCD and a color camera attached to the microscope. The structure of the recorded images is determined through Fourier transform analysis. It is shown that the recorded images are lens holograms formed by the interference of the wave-fronts generated by the crystals and nano-spheres. Fourier transform algorithms and edge detection algorithms are utilized to obtain the dimensions of the crystals. The power of Gabor’s idea when he invented holography is again proven in this study. If the problem of super-resolution is viewed from the point of view of the Theory of Communications, the fact that one can register both amplitude and phase of a signal of a self-luminous object provides the means of reaching spatial resolutions with average standard deviation of ±3 nm using helium-neon laser illumination of =632.8 nm. The resolution that can be achieved depends on the structure of the observed material, in the present case ±5d, where d is the distance of the atomic planes of the NaCl. Some preliminary analysis has been done also for the polystyrene nano-spheres. With improvements in the hardware and software higher resolutions may be feasible.