ИСТИНА

Direct laser writing (DLW) is a promising way for printing 3D micro-objects. Recently this method has been applied to fabricate X-ray optical elements [1]. However, due to the finite resolution of a DLW - a finite size of the minimal polymerized volume ("voxel") and voxel's ellipsoidal shape - the parabolic profile distorts. This distortion leads to the change of curvature radius and, therefore, the optical performance. This shape distortion can be even more significant in the case of post-processing [2]. In this work, we corrected a parabolic X-Ray lens model, taking into account the voxel size. In the simplest case for constant laser power, the problem can be solved analytically. To prove the corrected model's efficiency, we compared the vertical sections of lenses printed with and without correction (see Fig.1). To conclude, we have corrected the 3D model of the parabolic lens for DLW. The research can be helpful for further advance of DLW-fabrication of X-Ray optical elements. This work was supported by Russian Science Foundation (20-12-00371), the Ministry of Science and Higher Education of the Russian Federation (14.W03.31.0008), and the MSU Quantum Technology Center. [1] A. Barannikov, M. Polikarpov, P. Ershov, V. Bessonov, K. Abrashitova, I. Snigireva, V. Yunkin, G. Bourenkov, T. Schneider, A. A. Fedyanin, and A. Snigirev, “Optical performance and radiation stability of polymer X-ray refractive nano-lenses”. J. Synch. Rad., 26(3):714–719 (2019). [2] M.I. Sharipova, T.G. Baluyan, K.A. Abrashitova, G.E. Kulagin, A.K. Petrov, A.S. Chizhov, T.B. Shatalova, D. Chubich, D.A.Kolymagin, A.G. Vitukhnovsky, V.O. Bessonov, and A.A. Fedyanin, “Effect of pyrolysis on microstructures made of various photoresists by two-photon polymerization: comparative study,” Opt. Mater. Express 11, 371-384 (2021).