Hiring Institution
École Centrale de Lyon (EC Lyon)

PhD-Awarding Institutions
École Centrale de Lyon (EC Lyon)
RMIT University (RMIT)

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Option 1

Fully reconfigurable chip-based Mid-IR supercontinuum source

The Mid-infrared (Mid-IR) wavelength range – from 2.5 to 13 µm – is currently experiencing a huge surge in interest for an enormous range of applications that affect almost every aspect of our society, from compact and highly sensitive biological and chemical sensors, imaging, defense and astronomy.

Despite their recognized potential, Mid-IR technologies are still limited in their range of applications, largely because of the size of the Mid-IR devices and the prohibitive costs of the instruments used due to the lack of compact Mid-IR optical devices and in particular compact and broadband sources despite recent breakthrough in integrated mid-IR supercontinuum sources.

The PhD’s project will address the current –bulkiness and tunability– challenges of the mid-IR supercontinuum technology through realizing a robust, reliable and miniaturized broadband supercontinuum source with highly tunable performance.

The two main objectives of the PhD’s project will be to:
– co-integrate a compact and powerful fiber-based optical pump with a highly nonlinear photonic chip;
– exploit electrically controlled phase change materials at the core of the device.

[1] F. K. Tittel, D. Richter, and A. Fried, “Mid-Infrared Laser Applications in Spectroscopy,” in Solid-State Mid-Infrared Laser Sources, (Springer Berlin
Heidelberg, 2003).
[2] M. Sinobad, et al., Optica 5, 360 (2018).
[3] M. Sinobad, et al., J. Opt. Soc. Am. B 36, A98 (2019).
[4] M. Sinobad, et al., Opt. Lett. 45, 5008 (2020).
[5] A. Della Torre, et al., “Mid-infrared supercontinuum generation in a low-loss germanium-on-silicon waveguide,” APL Photonics 6, 06102 (2021),
https://doi.org/10.1063/5.0033070

Option 2

Mid-IR Optical Frequency Comb on a chip

Research conducted at the beginning of the millennium on optical frequency comb generation was crowned in 2005 by the Nobel Prize in Physics awarded to John Hall and Theodore Haensch. The need for more compact, robust, and energy efficient sources offering high repetition rates (> 1 GHz) has favoured the emergence of a different approach to comb generation, based on nonlinear chip-based microresonators [1,2] that are manufactured by leveraging microelectronics processes and infrastructure. These “MicroCombs” have recently led to an explosion of record demonstrations, e.g. optical clocks on a chip [3], LIDAR [4], data transmission [5], neural networks [6], mostly using the Si3N4 or Hydex platform. INL/ CEA-Leti contributed to these efforts, with the development of Si3N4 dispersion engineered waveguides with very low loss [7], making possible the co-integration of combs with silicon optoelectronics [8] and the demonstration of an integrated Si3N4 comb source pumped by a butt-coupled DFB III-V laser (InGaAsP/InP) [9]. All these demonstrations are mainly centred around 1550 nm at telecom wavelength whereas many applications such as spectroscopy, gas detection, environmental surveillance, free space communication etc require combs in the mid-infrared (mid-IR – in the molecular fingerprint region beyond 3 µm).

Our first objective is to demonstrate the first “Micro-comb” on a CMOS compatible platform to cover the actual mid-IR region. We will exploit the SiGe and Ge platform to create highly nonlinear resonators in the mid-IR with high Q-factor, suitable dispersion and repetition rate (from tens GHz to few GHz FSR as required for direct gas sensing). We will also explore other platforms like LNOI, LNOS or GaP.

Our second objective is to demonstrate an on-chip dual-comb spectrometer operating in the mid-IR. We will aim at demonstrating the usefulness of these compact spectrometers for sensing applications such as pollution monitoring, breath analysis.

There will be opportunities to travel and interact with our partners on a national and international level (both Europe/France and Australia).

1. L. Razzari, et al. “CMOS-compatible integrated optical hyper-parametric oscillator,” Nat. Photonics 4, 41-45 (2010).
2. T. J. Kippemberg, R. Holzwarth and S.A. Diddams, ”Microresonators-based optical frequency combs,” Science 332, 555-559 (2011)
3. S. A. Diddams, K. Vahala, T. Udem, Science, vol. 369, p. 267, 2020.
4.J. Riemensberger, A. Lukashchuk, M. Karpov, W. Weng, E. Lucas, J. Liu, T. J.Kippenberg, Nature, vol. 581, p. 164, 2020.
5.B. Corcoran, et al., Nat. Commun., vol. 11, p. 2568, 2020.
6. X. Xu, et al., Nature, vol. 589, p. 44, 2021.
7. H. El Dirani, et al. Opt. Express 27, 30726-30740 (2019)
8.H. El Dirani, et al., Appl. Phys. Lett. 113, 081102 (2018); https://doi.org/10.1063/1.5038795
9. Sylvain Boust, Houssein El Dirani, et al., J. Lightwave Technol. 38, 5517-5525 (2020)

Option 3

Mid-IR Integrated Nonlinear Optics

The Mid-infrared (Mid-IR) wavelength range – from 2.5 to 13 µm – is currently experiencing a huge surge of interest for an enormous range of applications that affect almost every aspect of our society, from compact and highly sensitive biological and chemical sensors, to imaging, defence and astronomy.

Despite their recognized potential, Mid-IR technologies are still limited in their range of applications, largely because of the bulky size of the Mid-IR devices and the prohibitive costs of the instruments used. Compact Mid-IR optical devices are indeed currently lacking and despite recent breakthroughs related to integrated mid-IR supercontinuum sources, compact and broadband sources in particular are critically missing.

Our strategy is therefore based on the development of an integrated hybrid Mid-IR platform, involving the miniaturization of optical components and their integration on a planar substrate made of materials with remarkable optical properties (particularly in terms of transparency and non-linearities) at MIR wavelengths like SiGe alloys, LiNbO3 or emerging III-V semi-conductors like GaP.
The student’s project will focus on one of the fundamental issues of integrated Mid-IR, namely efficient and broadband MIR sources and their integration into an optical circuit. In this thesis, we will exploit nonlinear-phenomena over an unprecedented wavelength range (from visible to Mid-IR). The aim will be to develop an on-chip supercontinuum (and potentially combs) that can cover a broad wavelength span, from the visible to the mid-IR.
There will be opportunities to travel and interact with our partners on a national and international level (both Europe/France and Australia) including European industry (CEA-LETI and others).

[1] F. K. Tittel, D. Richter, and A. Fried, “Mid-Infrared Laser Applications in Spectroscopy,” in Solid-State Mid-Infrared Laser Sources, (Springer Berlin
Heidelberg, 2003).
[2] M. Sinobad, et al., Optica 5, 360 (2018).
[3] M. Sinobad, et al., J. Opt. Soc. Am. B 36, A98 (2019).
[4] M. Sinobad, et al., Opt. Lett. 45, 5008 (2020).
[5] A. Della Torre, et al., “Mid-infrared supercontinuum generation in a low-loss germanium-on-silicon waveguide,” APL Photonics 6, 06102 (2021), https://doi.org/10.1063/5.0033070

Dr. Christian Grillet
Prof. Christelle Monat
Sebastien Cueff
Dist. Prof. Arnan Mitchell
Andy Boes
Thach Nguyen
Guanghui Ren

Physics, Photonics, Nonlinear Optics