Walther, Herbert Laser Physics, Max Planck Institute of Quantum Optics, Max Planck Society;
Walther, H. (2003). Generation and Detection of Photon Number States on Demand. In I. Antoniou, V. Sadovnichy, & H. Walther (Eds.), The Physics of Quantum Communication. Proceedings of the XXII Solvay Conference on Physics (pp. 410-426). Singapore: World Scientific.