Hybrid III-V-on-Silicon nanophotonics

Non hermitian photonics...

Accounting for losses and their exploitation in photonic devices has proven to be very fruitful in producing new behaviors over the last decade, within the framework of non-Hermitian physics. When several optical resonances are coupled, exceptional points (EPs) correspond to a singularity where several eigenvalues of the system coalesce together with their corresponding eigenvectors. EPs are associated with a wide range of phenomena, including, for example, spectral and spatial nonreciprocal behaviors, enhanced sensing operations, and unique topological properties. While many realizations have been made using passive or active systems, the on-chip realization of these functionalities remains difficult due to the necessity for fine control techniques of the individual properties of the resonators. In Ref (1), we demonstrated pump-controlled directional emission from two III-V semiconductor coupled nanolasers (see SEM image in bottom left figure) that interact distantly via an integrated SOI waveguide (see top artistic view). We use integrated metallic micro-heaters (see right µscope image) to independantly tune the nanolasers emission frequencies, such that EPs can be well identified. This coupling scheme unusually enables both frequency and loss coupling between the two cavities, which can be advantageously exploited to reach EPs by either detuning the cavities or controlling the gain of the nanolasers. The system can be readily reconfigured from bidirectional to unidirectional emission by adjusting the pump power. 

While the above results have mostly been obtained below the lasing threshold, rich nonlinear dynamical phenomena occur once lasing begins. Interestingly, at the nanoscale, it is possible to achieve coupling lengths that are sufficiently small for coupling delays to be neglected compared to the cavities' photon lifetime. Collective modes can, therefore, build up while being generally subjected to highly nonlinear dynamics, which enables a confrontation of both perspectives in the context of, for example, synchronization, self-sustained oscillations, or self-pulsing dynamics. 

Overall, the combined fundamental study of nonlinear dynamics and mode-coupling in nanolaser arrays will uncover new behaviors that can be harnessed in integrated photonic circuits, paving the way for innovative nanophotonic devices.


People involved:
Manar Reriouedj (PhD student)
Roberto Gajardo (Postdoc)
Guilhem Madiot, Fabrice Raineri, Guillaume Huyet (PIs)

Alumni
Kristian Seegert (PhD student at DTU, 2025)
Raphael Sauvage-Marchin (MSc intern, 2025)
Jan Niklas-Topf (MSc intern, 2025)
Quentin Chateiller (PhD student at C2N, 2016-2020)
 

People involved:
Daniel Lizotte (PhD student)
Guilhem Madiot, Fabrice Raineri, Guillaume Huyet (PIs)

Alumni
Maxime Delmulle (PhD student at C2N, 2019-2023)


 

The all-pervading development of photonics in the last decades is intimately linked to the advent of the society of information and communication and to the stupendous growth in world data transfer. As a necessary evolution, attention is now directed to optical datacom and computercom which concern data links down to the mm scale. For these, the issues to tackle are the dispatching and sorting of a mind boggling amount of information. The very nature of optics offers the potential to obtain the required high data transmission and processing rates with low power consumption. The use of Silicon photonics has been clearly identified in all roadmaps  as a means to achieve the most awaited convergence of microelectronics and photonics on a chip by overcoming electrical interconnect limitations in bandwidth and power efficiency.  However to implement this paradigm change, it is crucial to meet up with the exigencies for the performance of the optoelectronic devices which are extremely high.

Novel directions in this domain are of paramount importance to solve this problem. Nanophotonics with its capacity to provide ultimate light-matter interaction will surely be at the centre of the solution. However, in nanophotonics, bridging the gap between fundamental studies and real life device implementation is a formidable task. This is exactly our ambition.

For the last years, our team has been concentrating its efforts on expoiting the unique optical properties of photonic crystals structures. We have been employing these emblematic wavelength-scale strutures to achieve:

 

Inp Nanolasers

 

Involved People: Francesco MANEGATTI (PhD), Dimitris FITSIOS (Postdoc), Fabrice RAINERI (PI)

 

 

NANO-AMPLIFIERS

Involved People: Francesco Manegatti (PhD), Dimitris FITSIOS (Postdoc), Fabrice RAINERI (PI)

 

Involved People: Lea CONSTANS (PhD), Francesco MANEGATTI (PhD), Dimitris FITSIOS (Postdoc), Fabrice RAINERI (PI)

Future developments in optical networks will rely crucially on all-optical processing. All-optical processing is based on optical nonlinear effects where an optical signal impacts on the propagation of another one through their interaction with the matter. One of the advantages of all-optical devices over opto-electronic ones is their inherent potential to provide higher bandwidth for high speed data transmission and treatment.

Recently, the drive towards the miniaturisation and the energy efficiency of such devices motivated important efforts in research especially in the nanophotonics domain. Our team aims at developping innovative nonlinear devices based on III-V/Silicon hybrid nanostructures which take advantage of the large dynamic nonlinearities of quantum-confined III-V active materials (quantum well or quantum dots) embedded in photonic crystal nanocavities. Currently, our interest lies in:

Collaborators:

Alfredo De Rossi and Sylvain Combrié (Thales Research and Technologies)
Theoni Alexoudi and Nikos Pleros (Aristotle University of Thessaloniki)

Involved People: Gabriel MARTY (PhD), Fabrice RAINERI (PI)

We endeavour to tap the properties of semiconductor nanostructures such as photonic crystals for nonlinear optics, especially for second and third order nonlinear effects at telecom wavelengths. Nonlinear optics in nanostructures have grabbed, for quite some time, the attention of many researchers as the structuring of the matter at the wavelength scale promises the achievement of particularly efficient nonlinear processes with reasonable optical powers. This opens up a vast panoply of devices and functionalities such as frequency doublers, parametric amplifier, frequency combs or entangled photon sources, which may be integrated into a photonic circuit. Our current interests in the domain lie in:

Collaborators:

Alfredo De Rossi and Sylvain Combrié (Thales Research and Technologies)
Bart Kuyken and Gunther Roelkens (Ghent University)
François Leo and Simon-Pierre Gorza (Université libre de Bruxelles)