Non linearity enhanced by strong coupling

Our latest results have just been accepted for publication in Nature Communications. In this work we strongly couple the exciton of cyanine dye J-aggregates to an optical mode of a Fabry-Perot (FP) cavity, and achieve an enhancement of the complex nonlinear refractive index by two orders of magnitude compared with that of the uncoupled condition. Moreover, the coupled system shows an ultrafast response of ~120 fs that we extract from optical cross-correlation measurements. The ultrafast and large enhancement of the optical nonlinar coefficients in this work paves the way for exploring strong coupling effects on various third-order nonlinear optical phenomena and for technological application. The paper will be soon accessible in Open Access on Nature Communications website and on our publications page.

Double departure

We have started the year with two members less in the group : Robrecht Vergauwe and Samuel Albert have indeed finished their postdoctoral contracts in the end of December 2020. They were both very supportive for younger labs members and involved in organizing conviviality moments, contributing to the good cohesion of the team. We will miss their presence in the lab and we wish them all the best for their future !

Source : Minghao Li

2021

Most of the people were happy to see the end of 2020 and expect the new year as a renewal, more than ever. A lot of pressure on the shoulders of 2021 then ! Let’s hope it will indeed be a “bit more normal”…  We wish happiness, health and success to all our friends and collaborators around the world !

Symmetry yrtemmyS

Vibrational strong coupling (VSC) has recently been shown to change the rate and chemoselectivity of ground state chemical reactions via the formation of light‐matter hybrid polaritonic states.Our recent observation that vibrational mode symmetry has a large influence on charge transfer reactions under VSC suggested that symmetry considerations could be used to control other types of chemical selectivity. We thus explored the stereoselectivity of the thermal electrocyclic ring‐opening of a cyclobutene derivative, a reaction which follows the Woodward‐Hoffmann rules, under VSC. The direction of the change in stereoselectivity depends on the vibrational mode that is coupled, as do changes in rate and reaction thermodynamics. All this is summarized in a new publication, resulting from a collaboration with Joseph Moran‘s group, that just appeared in Angewandte Chemie in Open Access, but also in our publication page.

Welcome to Luis !

Since a week, we have the pleasure to welcome our first brazilian lab member, Luis Pires. Luis is a physicist by education, now specialist of optical tweezers and colloidal interactions. He received his master and PhD from the Federal University of Rio de Janeiro, Brazil, and did a six month internship at Indiana University – Purdue University Indianapolis, USA. Welcome to him !

 

Anoop’s departure

A week ago, it was the last day in the lab of our friend and colleague Anoop Thomas, who spent more than 5 years among us. We will all miss his good mood and curiosity, his knowledge in chemistry, his assistance and availability for the younger students and more generally, for all people in the group… but we are very happy for him that he was offered a great position of assistant professor at the Department of Inorganic and Physical Chemistry, at Indian Institute of Science (IISc) Bangalore. We wish him and his family all the best for the future and will keep in touch !

Minghao phD Defense

It is our pleasure to announce the phD defense of Minghao Li next wednesday, 18th of November, at 2pm. His work, entitled

Mueller polarimetry for probing supramolecular and optical chiralities

has been performed under the supervision of Dr Cyriaque Genet.

The defense, making use of a videoconferencing system, will take place in ISIS2 seminar room but due to sanitary conditions, access will be limited.

Welcome to Sudipta !

A new postdoctoral researcher joined the group one week ago : Sudipta Saha is a physicist with specialization in optical physics and photonics. He received his integrated MS-PhD in physical sciences from the Indian Institute of Science Education and Research Kolkata, India. Subsequently, he conducted his postdoctoral research at the Florida International University, USA. Welcome to him !

Welcome to Shahana !

We have the pleasure to welcome a new phD student coming from India, Shahana Nizar. She completed her master degree from IISER Thiruvananthapuram in June 2020 with chemistry as major subject and physics as minor subject. During her master thesis, she has been working on the chiroptical properties of aggregates, under the supervision of Pr. George Thomas.

Mirrors and nothingness…

An interesting article written by Katrina Krämer just appeared in Chemistry World, about the control of chemical reactions via hybrid-light matter states. It summarizes, via the opinion of some actors of this research field like T.W. Ebbesen, J. Yuen-Zhou or Felipe Herrera, what is known already, what still needs to be understood and what could be the future of the field.