【Date and Time】27-November-2025 15:00 (Beijing time)

【Venue】Room 320

【Host】Quanyong Lu(BAQIS)

【Title】 Optical frequency combs and free space data transmission using quantum cascade lasers at 10 μm

【Speaker】 

Carlo Sirtori is a Chair Professor at the école normale supérieure (ENS) in Paris. After completing his PhD in Milan, Carlo Sirtori moved to Bell Laboratories (NJ, USA) in 1990 working on the quantum properties of low dimensional semiconductor quantum structures. During the year at Bell Labs he made some major contribution such as the first demonstration of the “Quantum Cascade Laser”. In 1998 he joined THALES Research & Technology in France, where he was a group leader and then head of the "Semiconductor Lasers" department. After a few years of experience as a manager, he took an academic position to focus his research on quantum physics and technology. In 2003 he was appointed professor at the University Paris-Diderot where he was director of the MPQ laboratories from 2010 until 2018. The same year he left the University to join, Ecole normale supérieure (Paris) as professor, holder of the ENS-THALES Chair and director of the Master Quantum Engineering.

【Abstract】

Quantum photonics in the mid-infrared and terahertz spectral regions is opening new routes for compact, high-performance sources and detectors that bridge quantum concepts with real-world applications. In this talk, I will begin by discussing the fundamental physical concepts underlying quantum lasers and in particular the optical. Next, I will present the origin of frequency-modulated (FM) mode-locking in quantum cascade (QC) lasers and illustrate the multi-heterodyne setup used to retrieve the temporal evolution of the laser emitted electric field. Then, I will describe the operation of unipolar quantum optoelectronic (UQO) devices, which enable high-speed free-space optical communication systems operating at a wavelength of 10 μm. These devices operate at room temperature and are integrated into metasurfaces for enhanced performance. Data transmission rates exceeding 60 Gbit/s have been achieved using UQO devices together with standard telecom coding schemes and equalization techniques. Finally, I will conclude my talk by highlighting some of the most important applications of mid-IR and THz quantum photonic devices, illustrating how quantum-engineered semiconductor devices continue to expand the frontiers of quantum technology.

Reference:

1.Unipolar quantum optoelectronics for high-speed direct modulation and transmission in 8-14?μm atmospheric window. Nat Commun 15, 8040 (2024).

2.Metamaterial unipolar quantum optoelectronics for mid-infrared free-space optics. APL Photonics 9, 110801 (2024)

3.Heterodyne coherent detection of the electric field temporal trace emitted by frequency-modulated comb lasers Optica 11, 1220-1225 (2024).

4.Electronic transport driven by collective light-matter coupled states in a quantum device. Nat Commun 14, 3914 (2023).

5.Room-temperature nine-μm-wavelength photodetectors and GHz-frequency heterodyne receivers. Nature 556, 85-88 (2018).