Erlangen 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

Q: Fachverband Quantenoptik und Photonik

Q 3: Ultrashort Laser Pulses

Q 3.8: Vortrag

Montag, 5. März 2018, 12:15–12:30, K 0.023

Micro-sized synthesis of customized 3D GRadient INdex elements by femtosecond laser lithography — Neus Oliver, •Alejandro Jurado, Raphael Wittkowski, and Cornelia Denz — Institut für Angewandte Physik (WWU Universität) Münster, Germany

Increasing interest in micro-scale optics has led to the development of novel miniaturization techniques, among which laser lithography stands out as a powerful approach. Laser lithography allows the design and synthesis of arbitrary geometries to act as lenses, waveguides or diffractive components. Advances in this field have been focused, not only on improving the spatial resolution, but also on tuning the optical properties of the structures, such as the refractive index (RI). Specifically, elements with a spatial variation of the local RI can be obtained (GRadient INdex). The dependence of the attained RI with the exposure parameters in various polymers has been addressed, enabling the realization of 2D and multilayered GRIN structures. In this work, hybrid polymer Ormocomp is used to fabricate GRIN micro-structures via femtosecond laser lithography based on two-photon polymerization (TPP). We characterize the RI of our samples with phase maps obtained through interferometry and Fourier analysis methods. As calibration, the relation between laser power and the RI is studied. With our procedure, 3D GRIN distributions down to tens of micrometers can be achieved. We complement our results with ray tracing simulations for optimization of GRIN design. Our approach represents a comprehensive and versatile strategy for the tailored fabrication of 3D GRIN micro-optical systems, in which the downscaling is foreseen.