St. Petersburg Polytechnic University Journal: Physics and Mathematics Научно-технические ведомости СПбГПУ. Физико-математические науки 2304-9782, 2618-8686, 2405-7223 41 10.18721/JPM.173.241 Nonlinear optical phenomena in mesoporous SiO2 and Si/SiO2 nanoparticles Нелинейные оптические эффекты в мезопористых SiO2 и Si/SiO2 наночастицах 0000-0002-6247-9868 Mastalieva Viktoriia strindberg76@mail.ru Neplokh Vladimir vneplox@gmail.com Aybush Arseny aiboosh@gmail.com Stovpiaga Ekaterina kattrof@gvg.ioffe.ru Eurov Daniil edan@mail.ru Vinnichenko Maxim mvin@spbstu.ru Karaulov Danila karaulov.da@edu.spbstu.ru 0000-0002-1571-209X Kirilenko Demid demid.kirilenko@mail.ioffe.ru 0000-0003-2956-6561 Golubev Valery golubev@gvg.ioffe.ru Smirnov Alexander Alex.Smirnov@mail.ioffe.ru 0000-0002-9257-6183 Makarov Sergey s.makarov@metalab.ifmo.ru Kurdyukov Dmitry kurd@gvg.ioffe.ru 0000-0001-9792-045X Mukhin Ivan muhin_is@spbstu.ru Alferov University Peter the Great St. Petersburg Polytechnic University ITMO University Ioffe Institute 23 12 2024 17 3.2 207 211

In this work we study the optical response of mesoporous SiO2 and Si/SiO2 nanoparticles considering different fabrication and post-synthesis treatment processes. We show that thermal annealing of mesoporous Si/SiO2  nanoparticles transforms the Si phase from amorphous to crystalline and enhances the second harmonic generation response.

 second harmonic generation silicon nanostructures mesoporous nanoparticles IR visualizer