ИСТИНА

Photonic Integrated Circuits (PICs) provide great opportunities for optical calculations, including the neuromorphic applications. Nowadays there are many PICs designed in silicon and hybrid materials, mostly made by electron beam lithography. Silicon-based PICs demonstrate impressive results, but face some manufacturing restrictions, i.e. two-dimensionality and constant refractive index of all circuit elements. In this work we demonstrate polymer PIC elements made by two-photon lithography. This method provides opportunity to create three-dimensional microstructures with sub-micrometer resolution and gradient refractive index. Moreover, two-photon lithography allows printing the whole circuit on a single wafer, which is convenient for manufacturing process. We have designed various three-dimensional optical elements including coupling gratings, curved waveguides and microring resonators of different radii, which are combined in photonic transistor design for near-IR (800 nm) and telecommunication (1550 nm) wavelengths. Photonic nanostructures have been made of two commercially available photoresists - OrmoComp and SZ2080. To compensate the radiation losses during the light propagation in the curved waveguide, we rapidly adjusted laser power during the printing process. As a result, we demonstrate the application of two-photon lithography to manufacture the polymer PIC elements that provides the opportunity to overcome the imperfections of currently widely spread silicon PICs.