Nonlinear Quantum Optics

Nonlinear quantum optics is based on the generation of quantum states of light using nonlinear processes. In this context, the Theoretical Quantum Optics group investigates possibilities to introduce novel correlations and entanglement between a different number of photons generated through special pump beams or a combination of nonlinear processes. Since one of the prime uses of entangled photons are quantum communication and quantum key distribution, this topic fits perfectly into the research direction of the Institute of Applied Physics. In the same way, such unique states foster the development of new quantum-imaging schemes based on correlation measurements.

At the same time, the group studies the generation of light through scattering processes of relativistic electrons at optical potentials and investigates the properties of the generated radiation, as well as the transition to classical free-electron lasers.

S. Schaffrath, D. Derr, M. Gräfe, & E. Giese
Quantum imaging beyond the standard-quantum limit and phase distillation
New Journal of Physics 26, 023018 (2024)
C. M. Carmesin, P. Kling, E. Giese, R. Sauerbrey & W. P. Schleich
Quantum and classical phase-space dynamics of a free-electron laser
Physical Review Research 2, 023027 (2020)
W. Zhang, R. Fickler, E. Giese, L. Chen & R. W. Boyd
Influence of pump coherence on the generation of position-momentum entanglement in optical parametric down-conversion
Optics Express 27, 20745–20753 (2019)
S. Lemieux, E. Giese, R. Fickler, M. V. Chekhova & R. W. Boyd
A primary radiation standard based on quantum nonlinear optics
Nature Physics 15, 529–532 (2019)
M. I. Kolobov, E. Giese, S. Lemieux, R. Fickler & R. W. Boyd
Controlling induced coherence for quantum imaging
Journal of Optics 19, 054003 (2017)