Hybrid QCL-SiGe photonics circuits for mid-IR frequency comb sources. (M/F)

19 Mar 2024
Job Information

Organisation/Company

CNRS

Department

Centre de Nanosciences et de Nanotechnologies

Research Field

Engineering
Physics
Technology

Researcher Profile

First Stage Researcher (R1)

Country

France

Application Deadline

8 Apr 2024 - 23:59 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

35

Offer Starting Date

1 Oct 2024

Is the job funded through the EU Research Framework Programme?

HE

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

The Center for Nanoscience and Nanotechnology (C2N) is a joint research unit between the CNRS, the University of Paris-Saclay and the University of Paris Cité located in Palaiseau, near Paris. The laboratory carries out world-renowned research projects in the fields of photonics, materials, nanoelectronics, microsystems and nanofluidics. The C2N has a staff of nearly 400 people and hosts one of the largest university nanotechnology centers in France, with a 2900 m2 clean room.
Within C2N, the Silicon Photonics group (https://minaphot.c2n.universite-paris-saclay.fr/en/ ) has extensive expertise in passive and active photonic devices on silicon, silicon nitride and germanium. The group is at the forefront of photonics research, with several pioneering demonstrations of optoelectronic devices, including optical modulator, photodetectors, passive devices, metamaterials, and metasurfaces. The group has access to several optical setups for the active and passive characterization of photonic devices from 600 nm to 16μm wavelength. The research group's main anticipated applications are optical telecommunications/interconnects, microwave photonics, biochemical and gas sensing, spectroscopy and datacom.
This position offers the opportunity to work within an enthusiastic and international team in the exceptional C2N environment. We offer access to state-of-the-art manufacturing infrastructure and characterization laboratories, with the ability to propose and investigate new research ideas.

Mid-infrared (mid-IR) spectroscopy is a universal way to identify chemical and biological substances. Indeed, when interacting with a light beam, most molecules are responsible for absorption at specific wavelengths in the mid-IR spectrum, allowing to detect and quantify small traces of substances. Many molecules of major importance for pollution monitoring or healthcare (alkanes, ozone) have their fingerprint in mid-infrared (mid-IR) spectral range, between 5 and 12 µm. To reach this spectral range, the solution of choice for the laser source is based on Quantum Cascade Lasers (QCL) which have reached an impressive level of technological maturity in the recent years. These devices employing intersubband transitions in quantum wells structures now form the basis for an increasing range of applications, particularly in the areas of high-sensitivity trace gas detection and infrared countermeasures. They exhibit a low footprint, up to watt-level average power with a broad spectral bandwidth.
The development of frequency combs in this mid-IR spectral range is currently attracting a lot of attention. An optical frequency comb is of a set of regularly spaced laser lines of the same frequency in the spectrum and mutually coherent. Frequency combs have enabled many scientific advances, first in metrology and then extended to many fields. Dual comb spectroscopy has been proposed as a powerful technique for real time sampling of optical spectra, enabling fast and accurate measurement for high sensitivity spectroscopy. In this scheme, two optical frequency combs with slightly different repetition rates are mixed and detected by a photoreceiver that translates the optical signal into the radiofrequency (RF) domain. As a result, each pair of comb lines produces a signal at a unique RF frequency, allowing a single shot measurement of the optical spectra.
Many approaches for frequency comb generation have been and are currently being explored, including frequency-comb QCL, non-linear frequency conversion from doped-fiber lasers, microresonators, spectrum broadening in non-linear waveguides or electro-optic devices. However today the main challenge of mid-IR frequency combs is to achieve compact, turn key systems, compatible with compact QCL sources.
In this context the objective of the PhD is to explore the potential of non-linear optics and self-injection locking in hybrid QCL-SiGe photonics circuit to generate stable and compact frequency combs.
Within the PhD, different strategies will be explored, and the research activity will include:
- theoretical study, optical and electro-optical simulations, device designs
- clean room fabrication including definition of process flows, and mask designs
- experimental characterizations of passive and active devices within mid-IR optical bench
The work will be developed with many EU partners, in the framework of UNISON Pathfinder project (2024-2028)
Profile :
We are looking for a candidate holding a master degree in photonics. Some knowledge about photonics simulation and clean room fabrication will be appreciated.

Requirements

Research Field

Engineering

Education Level

Master Degree or equivalent

Research Field

Physics

Education Level

Master Degree or equivalent

Research Field

Technology

Education Level

Master Degree or equivalent

Languages

FRENCH

Level

Basic

Research Field

Engineering

Years of Research Experience

None

Research Field

Physics

Years of Research Experience

None

Research Field

Technology

Years of Research Experience

None

Additional Information

Website for additional job details

https://emploi.cnrs.fr/Offres/Doctorant/UMR9001-DELMOR-004/Default.aspx

Work Location(s)

Number of offers available

1

Company/Institute

Centre de Nanosciences et de Nanotechnologies

Country

France

City

PALAISEAU

Geofield

Where to apply

Website

https://emploi.cnrs.fr/Candidat/Offre/UMR9001-DELMOR-004/Candidater.aspx

Contact

City

PALAISEAU

Website

http://www.c2n.universite-paris-saclay.fr/fr/

STATUS: EXPIRED