Missions

We have an opening for a two-year post-doctoral appointment at University Paris Saclay (France) and CNRS, with the Centre for Nanosciences and Nanotechnologies (C2N). You will integrate the Mid-IR / THz Quantum Devices Team, specialized in the development of novel optoelectronic devices exploiting quantum electro-dynamic effects at mid-infrared wavelengths [1] [2]. Located south of Paris, the University Paris Saclay extends across a vast and rich local area and is ranked as France's top university. The salary level can be negotiated depending on the candidate experience. The project is supported by an ERC Advanced Grant (project SMART-QDEV).

The goal of this project is to develop non-linear devices based on intersubband transitions in III-V semiconductor heterostructures, and to use them for the control of frequency combs generated by interband cascade lasers (ICL) and quantum cascade lasers (QCL).

[1] M. Malerba, M. Jeannin, S. Pirotta, L. Li, A. G. Davies, E. Linfield, A. Bousseksou, J.-M. Manceau, and R. Colombelli, Appl. Phys. Lett. 119, 181102 (2021).
[2] E. Cortese, N. L. Tran, J. M. Manceau, A. Bousseksou, I. Carusotto, G. Biasiol, R. Colombelli, and S. De Liberato, Nat. Phys. 17, 31 (2021).

Activités

Scientific project:
Applications based on mid-infrared radiation (MIR, 3-12 um) have rapidly progressed in recent years, due to scientific and technological advances, and because of applications in fields related to spectroscopy, detection and communications. In particular, the generation of frequency combs with compact sources is a key aspect. Quantum cascade lasers already can generate frequency-modulated combs. And the interband cascade laser – a cascade laser source, but based on interband transitions – is very promising. ICLs now operate down to 7 um, and will soon cover a large part of the second atmospheric window (8 -12 um). They are ideal for generating amplitude modulated frequency combs [3], thanks to their dynamics and low threshold currents. Controlling and in particular stabilizing the frequency combs is very important for applications.

The project aims at developing ultra-fast [4] [5] and non-linear [6] devices based on intersubband transitions in III-V semiconductor hetero-structures, a topic the Host Team is intensively working on - and to use them for the control of frequency combs generated by interband cascade lasers (ICL) and quantum cascade lasers (QCL). The activity will rely on intersubband transitions between electronic states confined in semiconductor quantum wells [7]. Such transitions are the basic elements of quantum devices in the mid-infrared (quantum cascade lasers, infrared detectors with quantum wells). They are suitable for exploring new phenomena where cavity electrodynamics plays a fundamental role.
The post-doctoral project will evolve in this context, aiming to (i) develop non-linear mirrors that can electrically controlled amplitude and phase of the reflected beam and (ii) apply them to the control and stabilization of frequency combs generated by the ICLs and QCLs. The project also relies on recent developments by the team, namely ultra-fast (more than 10GHz) mid-IR modulators [5] and the use of strong light-matter coupling to tailor non-linearities [8].

One core idea is as follows: the stabilization of a semiconductor laser is generally obtained by electrical injection of an RF signal, referenced on a stable oscillator. We develop a new approach, when injection locking is not possible: modulating the reflectivity of the non-linear mirror judiciously coupled to the laser.

As a post-doc, you will devote initial efforts to the implementation of tools and measurement benches for frequency combs characterization in the mid-infrared (SWIFT spectroscopy in particular [9]). After which you will focus on the optical reinjection experiments in both QCLs and ICLs, using the ultra-fast mirrors the team recently developed [5]. You will develop new specific devices – supported by the team - and explore new injection schemes, as external cavity lasers instead of the optical re-injection regime.

References
[1] M. Malerba, M. Jeannin, S. Pirotta, L. Li, A. G. Davies, E. Linfield, A. Bousseksou, J.-M. Manceau, and R. Colombelli, Appl. Phys. Lett. 119, 181102 (2021).
[2] E. Cortese, N. L. Tran, J. M. Manceau, A. Bousseksou, I. Carusotto, G. Biasiol, R. Colombelli, and S. De Liberato, Nat. Phys. 17, 31 (2021).
[3] A. Schliesser, N. Picqué, and T. W. Hänsch, Nat. Photonics 6, 440 (2012).
[4] S. Pirotta, N.-L. Tran, A. Jollivet, G. Biasiol, P. Crozat, J.-M. Manceau, A. Bousseksou, and R. Colombelli, Nat. Commun. 12, 799 (2021).
[5] M. Malerba, S. Pirotta, G. Aubin, L. Lucia, M. Jeannin, J.-M. Manceau, A. Bousseksou, Q. Lin, J.-F. Lampin, E. Peytavit, S. Barbieri, L. H. Li, A. G. Davies, E. H. Linfield, and R. Colombelli, Appl. Phys. Lett. 125, (2024).
[6] M. Jeannin, E. Cosentino, S. Pirotta, M. Malerba, G. Biasiol, J.-M. Manceau, and R. Colombelli, Appl. Phys. Lett. 122, (2023).
[7] M. Helm, in Intersubband Transitions Quantum Wells Phys. Device Appl. I, edited by H. C. Liu and F. Capasso (Academic Press, 1999), p. 1.
[8] M. Jeannin, J. M. Manceau, and R. Colombelli, Phys. Rev. Lett. 127, 187401 (2021).
[9] D. Burghoff, T.-Y. Kao, N. Han, C. W. I. Chan, X. Cai, Y. Yang, D. J. Hayton, J.-R. Gao, J. L. Reno, and Q. Hu, Nat. Photonics 8, 462 (2014).
[10] E. Tournie and L. Cerutti, editors , Mid-Infrared Optoelectronics: Materials, Devices, and Applications. (WOODHEAD, 2019).

Compétences

Applicant profile and how to apply:
The project is experimental, but with an important part devoted to quantum/ electromagnetic simulations for device design. We are looking for highly motivated candidates with experience in some (not all) of the following fields: physics and technology of semiconductor devices; electromagnetic modeling; cleanroom manufacturing; laser physics; optoelectronic characterization techniques; design of quantum hetero-structures; RF/microwave technology.

The successful applicant will have completed an experimental PhD program in Physics, Optics or Engineering. The position is available immediately.

Applications, including cover letter and a CV, should be sent by email to Raffaele Colombelli (E-mail: raffaele.colombelli@c2n.upsaclay.fr or r.colombelli@gmail.com).

Contexte de travail

The project will also benefit from collaborations with the laboratories IES (Montpellier), TU Wien (Austria), LPA/ENS (Paris), ETH (Zurich/CH) and Univ. Leeds (UK).

The work will take place at the Center for Nanoscience and Nanotechnology, on the Plateau de Saclay.
The Center for Nanoscience and Nanotechnology (C2N) is a joint research unit of CNRS, Paris Saclay University, and Paris Cité University. The C2N, with approximately 410 staff, is located in Palaiseau (91), at the heart of the Paris Saclay campus.
C2N encompasses four scientific departments (photonics, materials, nanoelectronics, and nanobiofluidic microsystems). This position is located within the photonics department. This position requires access to the cleanroom.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

N/A