Keynote Speakers

Picture of Prof. Dr. Carsten Rockstuhl Picture of Prof. Dr. Carsten Rockstuhl Image: Private

Prof. Dr. Carsten Rockstuhl

Karlsruhe Institute of Technology, Germany

Climbing down the length scales: Computational Nanophotonics over time

Computational Nanophotonics explores in silico the interaction of light with structured materials. It does so out of intellectual curiosity but also to perceive applications of societal importance. Even though a 25-year experience says that the time that elapses from submitting a job to a computer system until it is executed remains constant, despite all the advances in hardware- and software, the type of systems that can be explored has changed drastically over time.

Whereas a long time ago, rather macroscopic dielectric structures in a simplified setting, e.g., in 2D, and with a restricted spatial extent were considered, we can nowadays study light in macroscopically large (many tens and even hundreds of wavelengths) 3D geometries while considering details at the nanoscale. Moreover, we can even solve inverse problems. It suggests that we can not just study the optical response of a given structure, but also identify the structure that offers a predefined optical response.

Even more fascinating, seamless multiscale modeling techniques have recently been developed where quantum chemical tools are used to study individual molecules' properties and consider them afterward in the design of macroscopically large photonic devices.

This presentation will sketch these larger trends in computational photonics along the lines discussed above and highlight future research directions. 

Picture of Prof. Dr. Nahid Talebi Picture of Prof. Dr. Nahid Talebi Image: Private

Prof. Dr. Nahid Talebi  

Institute for Experimental and Applied Physics, Kiel University, Germany


Probing Optical Excitations with Electron Beams

Electron microscopes are not only powerful imaging tools, but they also enable scientists to study quantum phenomena at the nanoscale. The flourishing field of ultrafast electron microscopy in recent years allows for exploring the quantum aspects of electron-photon interactions with electron microscopes and enables the investigation of the dynamics at the nanoscale spatial and femtosecond time resolution. Here, I outline our recent results where we have used cathodoluminescence spectroscopy to investigate the formation and propagation of exciton polaritons in van der Waals materials [1, 2]. Moreover, I will demonstrate and discuss a novel type of ultrafast electron microscopy that utilizes electron-driven photon sources [3] as internal radiation sources to map the dynamics of exciton polaritons and acquire their spectral phases [4]. Finally, our numerical investigations of the evolution of the electron wavepackets interacting with free-space and near-field light are demonstrated and will be highlighted as a roadmap for realizing the next generation of ultrafast electron microscopes flavoring the interaction of shaped electron wavepackets with light and matter [5].


[1] M. Taleb, F. Davoodi, F. Diekmann, K. Rossnagel, N. Talebi, Adv. Photonics Res. 3, 210012 (2022).

[2] F. Davoodi, M. Taleb, F. K. Diekmann, T. Coenen, K. Rossnagel, N. Talebi, ACS Photonics 9 (7), 2473–2482 (2022).

[3] N. Talebi, S. Meuret, S. Guo, M. Hentschel, A. Polman, H. Giessen, P. A van Aken, Nat. Commun. 10 (1), 599 (2019).

[4] M. Taleb, M. Hentschel, K. Rossnagel, H. Giessen, N. Talebi, Nat. Phys. (2023); link 

[5] N. Talebi, Phys. Rev. Lett. 125, 080401 (2019).

Picture of Dr. Falko Schmidt Picture of Dr. Falko Schmidt Image: Private

Dr. Falko Schmidt

PostDoctoral Researcher at ETH Zürich, Switzerland

2023 OPTICA Ambassador

To be announced...
Photo of Dr. Nadia Belabas Photo of Dr. Nadia Belabas Image: Private

Dr. Nadia Belabas

Centre de Nanosciences et de Nanotechnologies C2N, CNRS, Université Paris-Saclay, France


Many photons or many modes in the hollow of your hand: Semiconductors for quantum information processing

Quantum-dot-based semiconductor sources offer unprecedented brightness. Feeding synchronized indistinguishable photons emitted by such an efficient single-photon source into integrated reconfigurable photonic chips enables the implementation of multiphoton protocols. These on-chip protocols harness quantumness with remarkable performances and represent small-scale quantum computation in the "noisy intermediate scale" regime with linear optical gates. I shall detail instances and associated protocols. 

Semiconductors are also harnessed in the telecom domain to generate pairs of photons. I shall discuss how we use there the frequency dimension and integrated and fibered photonics together with silicon ring resonators to scale up.

These are steps forward for quantum circuits implemented with scalable technologies, for applications in quantum computing and secure communications.


[1] Mathias Pont, Giacomo Corrielli, Andreas Fyrillas, Iris Agresti, Gonzalo Carvacho, Nicolas Maring, Pierre-Emmanuel Emeriau, Francesco Ceccarelli, Ricardo Albiero, Paulo H. D. Ferreira, Niccolo Somaschi, Jean Senellart, Isabelle Sagnes, Martina Morassi, Aristide Lemaitre, Pascale Senellart, Fabio Sciarrino, Marco Liscidini, Nadia Belabas and Roberto Osellame High-fidelity generation of four-photon GHZ states on-chip, arXiv quant-ph 2211.15626

[2] Mathias Pont, Riccardo Albiero, Sarah E. Thomas, Nicolò Spagnolo, Francesco Ceccarelli, Giacomo Corrielli, Alexandre Brieussel, Niccolo Somaschi, Hêlio Huet, Abdelmounaim Harouri, Aristide Lemaître, Isabelle Sagnes, Nadia Belabas, Fabio Sciarrino, Roberto Osellame, Pascale Senellart, and Andrea Crespi Quantifying n-Photon Indistinguishability with a Cyclic Integrated Interferometer Phys. Rev. X 12, 031033 (2022) 

[3] Andreas Fyrillas, Boris Bourdoncle, Alexandre Maïnos, Pierre-Emmanuel Emeriau, Kayleigh Start, Nico Margaria, Martina Morassi, Aristide Lemaître, Isabelle Sagnes, Petr Stepanov, Thi Huong Au, Sébastien Boissier, Niccolo Somaschi, Nicolas Maring, Nadia Belabas, Shane Mansfield Certified randomness in tight space arXiv:2301.03536

[4] Antoine Henry, Dario Fioretto, Lorenzo M. Procopio, Stéphane Monfray, Frédéric Boeuf, Laurent Vivien, Eric Cassan, Carlos Ramos, Kamel Bencheikh, Isabelle Zaquine, Nadia Belabas Parallelization of frequency domain quantum gates: manipulation and distribution of frequency-entangled photon pairs generated by a 21 GHz silicon micro-resonator arXiv:2305.03457

Dr. Kevin Füchsel

CEO, Quantum Optics Jena GmbH, Germany 

Quantum Key Distribution with Entangled Photons – How Noble Price Physics Revolutionize Cybersecurity

Since the introduction of the "information superhighway" in the 1990s, digital communication has now encompassed all areas of social life and shrunk the world into a "global village”. The enormous reach of this rapid digital development is hard for many people to comprehend today, as email clients, social networks and VoIP services are used with unprecedented technological confidence. Sensitive segments of society include, for example, healthcare and finance, as well as federal and state governments themselves, with their multifaceted offices and agencies.

But the virtual world poses dangers that have real-world consequences. Digital crime with billions of damages, the sabotage of critical infrastructures, and the massive influence on politics and society have been seen in the past. A new threat arises with the usability of a powerful quantum computer, which endangers the cryptographic encryption processes currently in use and thus the security of the data sent. Due to this development, data security is not sustainable or only sustainable in combination with new post-quantum approaches. One of these approaches is quantum key distribution (QKD). This uses the laws of quantum physics to establish a provably physically tap-proof key at the sender (typ. referred to as "Alice") and receiver ("Bob") via a separate quantum channel. An eavesdropping attempt by "Eve" can be detected in the process. This secure key is then used to encrypt the message, send it over a regular internet connection, and decrypt it again at the receiver.  The use of probabilities and randomness in quantum physics to generate the symmetric keys thus enables completely new types of cryptography approaches that can withstand the attacks of high-performance computers and quantum computers, since they are not based on mathematical assumptions but on quantum physical laws and thus on physically verifiable principles.



To be announced...



To be announced...