Interference of coherent laser beams leads to appearance of periodical regions of different energy density. This periodical pattern (so-called optical lattice) is an interesting object for fundamental physics, since atoms trapped by periodical potential are suitable objects for studying propagation of spin waves, properties of super-solids or behaviour of Cooper pairs. At the other hand, the interference of the laser beams has also practical applications in production of optical gratings, meta-materials, and substrates for assembling of particles or cells. Laser light can also be used to change morphology or structure of thin polymer films. Experimental arrangement may consist of one or two laser beams irradiating the polymer surface. Diffraction pattern are formed either by interference of two incoming beams or by interference of primary and scattered laser beam. Formation of new structures on the polymer surface arises from periodical space distribution of the energy density replicating the light interference pattern. Another, simpler way of polymer modification is irradiation with focused laser beam by which a temperature gradient may be created in the irradiated spot. The temperature and surface tension gradients lead to redistribution of polymer material. In this way sub-micron structures can be prepared on the polymer surface. Depending on the experimental conditions different mechanisms such as ablation of materials, changes of polymers chemistry, photo-migration and photo-orientation processes, flow, under temperature and tension gradients, may govern the polymer modification by the laser light. In view of many factors taking part in the modification process a satisfactory explanation of the structure formation on polymers by laser irradiation has not been found yet. Microelectronic and optoelectronic technologies ever tend to a higher integrity and density of components. One of the prerequisites of this effort is preparation of welldefined structures on various substrates. Nano-patterning of polymers by the laser beams is novel and useful technique for controlled creation of parallel sub-micrometer patterns on polymer substrates which can be employed for the production of polymer based semiconductors and insulators. Besides common methods such as electron or ultraviolet laser lithography which are nowadays frequently used for the preparation of submicrometer patterns on vast range of substrates, the polarized light of excimer laser is an outstanding tool allowing mask-less, photoresist-less formation of periodic structures on polymers with periodicity of the order of the light wavelength.
|Title of host publication||Optical Lattices|
|Subtitle of host publication||Structures, Atoms and Solitons|
|Publisher||Nova Science Publishers, Inc.|
|Number of pages||58|
|Publication status||Published - 1 Dec 2011|
ASJC Scopus subject areas
- Physics and Astronomy(all)