Welcome and Introduction to SPIE Conference 11771

Welcome to the SPIE Quantum Optics and Photon Counting 2021, a part of Optics + Optoelectronics Digital Forum 2021! Conference co-chairs Ivan Prochazka, Roman Sobolewski, Martin Stefanak, Aurel Gabris and our Program Committee members, we all thank you for joining us in this exciting event and sharing your cutting-edge research with the colleagues from around the world.