On the morning of April 19, Professor Andrew Forbes was invited to visit the International Research Center for Advanced Photonics, International Campus, Zhejiang University, and gave a report entitled "Tailoring light at the source". In the report, Professor Andrew Forbes explained and answered the question of "how to generate an arbitrarily structured beam in a laser cavity". First, Professor Andrew Forbes introduced the concept of structured light. Based on the original polarized Poincare sphere, how to combine the structured vortex light to obtain a high-order Poincare sphere to represent an arbitrary vector structured beam. Then describes how such structured light is generated in traditional schemes, such as using phase plates or spatial light modulators outside the laser cavity. If the beam modulation element is integrated into the laser cavity, the desired vector structure beam can be obtained directly on the output end face of the cavity, which increases the energy utilization efficiency and system integration. Then, Professor Andrew Forbes introduced the principle of using concave mirror, spatial light modulator, metasurface and other schemes in the cavity to realize different vector structured light and the resulting beam effect. These vector beams can be used as independent channels for information transmission, providing a new technical path for the development of spatial structured light communication. The report aroused the interest of many teachers and students, who actively asked questions and discussed the content of the report, combined with their own research topics to generate new inspiration, and laid a good foundation for subsequent cooperation.
Professor Andrew Forbes is Distinguished Professor in the School of Physics, University of the Witwatersrand, South Africa, a Fellow of the South African Academy of Sciences, a Fellow of SPIE, OPTICA (formerly OSA) and the South African Institute of Physics, and currently editor-in-chief of the international Journal Journal of Optics. He is also a member of the editorial board of Opto-Electronic Science and has won the South African National Award (NSTF), the Alexander von Humboldt Foundation Georg Forster Award, and the Sang Soo Lee Award jointly awarded by OPTICA and the Korea Optical Society.