Optical isotropy of structure made by 2PP method for polarization-insensitive micro-optics

This paper presents the results of an experimental study on the polarization properties of polymer samples (parallelepipeds and prisms) fabricated from commercial Anycubic Clear resin using two-photon polymerization. Using crossed polarizers, measurements of the transmitted light intensity as a function of the analyzer rotation angle were performed. The angular dependences of transmission, obtained by rotating the analyzer, are in good agreement with a Malus's law-type dependence and exhibit no resolvable shift in the positions of the extrema relative to the reference measurement. For the spatial analysis of the relative optical phase, Mach–Zehnder interferometry at a wavelength of 1550 nm was employed, utilizing complex demodulation of the interference patterns. After co-registering the images for two orthogonal linear polarizations, cyclic phase difference maps were calculated, which are independent of the arbitrary choice of integer phase orders. In the investigated internal regions of several structures, a comparatively weak polarization dependence of the relative phase response is observed. These results demonstrate the potential of the studied microstructures for passive micro-optics with reduced sensitivity to linear polarization.