Professor Rene A. Ong, a professor of astronomy and astrophysics at the Department of Physics and Astronomy at the University of California, Los Angeles, specializing in research in the field of astro-particle physics and high-energy astrophysics, visited the Joint Laboratory of Optics. Professor Ong currently serves as a co-spokesman for the CTA (Cherenkov Telescope Array) consortium, in which the Joint Laboratory of Optics is also involved.