Comparative study of photoinduced surface-relief-gratings on azo polymer and azo molecular glass films

A representative azo polymer (BP-AZ-CA) and a typical azo molecular glass (IAC-4) were studied for their surface-relief-grating formation behavior to provide a deep understanding of the clear distinction between these two types of glassy material.

Digital holographic microscopy for real-time observation of surface-relief grating formation on azobenzene-containing films

Light-induced surface structuring of azobenzene-containing films allows for creation of complex surface relief patterns with varying heights, patterns which would be difficult to create using conventional lithography tools. In order to realize the full potential of these patternable surfaces, understanding their formation dynamics and response to different types of light fields is crucial. In the present work we introduce digital holographic microscopy (DHM) for real time, in-situ observation of surface-relief grating (SRG) formation on azobenzene-containing films. This instrument allows us to measure the surface topography of films while illuminating them with two individually controlled laser beams for creating periodically varying patterns. By utilizing the information of the grating formation dynamics, we combine multiple grating patterns to create pixels with wide gamut structural colors as well as blazed grating structures on the film surface. As long as the material behaviour is linear, any Fourier optical surface can be created utilizing this multiple patterning approach. The DHM instrument presented here has the potential for creating complex 3D surface reliefs with nanometric precision.

Механизм формирования наноструктур гексагональной симметрии на поверхности металлов последовательностью сдвоенных ультракоротких импульсов излучения ортогональной поляризации

An experimental results causing the ordered hexagonal symmetry surface nanostructures formation on metals under the sequence of scanned doubled collinear femtosecond pulses of orthogonal polarization and variable time-delay have been analized. It was shown that the structures production caused by the dynamic grating formation by the first pulse, excitation of two paires of surface plasmon polaritons in symmetric to the polarization vector directions of second pulse directions with 60 degrees angle between formed respective dynamic gratings and forth-fold first grating degeneration. So three gratings of three-flold symmetry about surface normal creates experimentally observable resonant surface relief of hexagonal symmetry.