Hiring Institution
Université Claude Bernard Lyon 1 (UCBL)

PhD-Awarding Institutions
Université Claude Bernard Lyon 1 (UCBL)
RMIT University (RMIT)

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Option 1

On chip mid-Infrared convertor

The mid-infrared (Mid-IR) wavelength range is extremely interesting for sensing applications between 2 and 15 um wavelength, but Mid-IR systems are bulky and expensive. Integrated Mid-IR optics are promising for miniaturizing such devices. However, integrating an on-chip source for a fully integrated system is very complex, especially for wavelengths above 2.3 µm [1]. For that purpose, the rare earth wavelength conversion strategy from IR to mid-IR is relevant.

This project aims to create on-chip Mid-IR sources using rare earth down conversion processes in an Al₂O₃ [2,3] host with Dy doping [4]. A standard photonic chip using both SiN and LNOI will be designed with waveguides which can support infrared and mid-infrared light respectively. A ring in the middle will be formed using doped Al₂O₃ formed using pulsed laser deposition (PLD) [5]. The project will explore direct fabrication of waveguides from the doped Al₂O₃ material at UCBL and will also explore hybrid integration of this doped material with waveguides fabricated from SiN and LiNbO₃ devices realised at RMIT.

Devices requirements and state of the art comparison for sensing applications will be studied in strong collaboration with Hemara company.

References:
[1] Ruijun Wang et al. Optica, 2017 https://doi.org/10.1364/OPTICA.4.000972
[2] Gassenq et al., Appl. Phys. A, 2023, https://doi.org/10.1007/s00339-023-06549-6
[3] Hendriks et al., Adv. Phys. X, 2021, https://doi.org/10.1080/23746149.2020.1833753
[4] Gassenq et al., Opt. Express, 2021, https://doi.org/10.1364/OE.416450
[5] Heuer et al., Opt. Mate. Express, 2018, https://doi.org/10.1364/OME.8.003447
[6] Boes et al. Science 2023 https://doi.org/10.1126/science.abj4396

Option 2

Rare earth tunable laser

Detection of chemical species is of interest in a wide range of applications, from biosensing to environmental monitoring. For such a task, precise measurements are made using tunable wavelength sources for spectroscopic evaluations, but equipments are bulky and expensive. Photonic integrated circuit (PIC) aims to miniaturize and combine multiple optical devices on a planar substrate to create compact, energy-efficient and complex on-chip functionalities [1]. In this area, ring resonator designs can be used for chemical sensing [2].

In this project, we want to design, fabricate, and characterize integrated tunable infrared sources based on micro-heaters integrated into doped ring resonators coupled to a SiN waveguide.
The Al₂O₃ doped laser [3] is coupled to a SiN waveguide. The laser is integrated by pulsed laser deposition and lift-off processing [4], [5]. Since a micro-heater is placed in the center of the ring, the resonance can be electrically tuned to control the emitted wavelength for spectroscopy applications.

Devices requirements and state of the art comparison for sensing applications will be studied in strong collaboration with Hemara company.

References:
[1] Baets et al., APL Photonics, 2016, https://doi.org/10.1063/1.5120004
[2] Kazanskiy et al., Micromachines, 2023, https://doi.org/10.3390/mi14051080
[3] Rönn et al., Nat. Commun., 2019, https://doi.org/10.1038/s41467-019-08369-w
[4] Gassenq et al., Opt. Express, 2021, https://doi.org/10.1364/oe.416450
[5] Gassenq et al., Opt. Lett., 2023, https://doi.org/10.1364/OL.486893

Option 3

Multiple source integration

Integrated optics merges the advantage of optics and electronics in a single chip for many applications like communication or sensing. However, the fabrication process for the manufacturing
is expensive and complex, especially for the laser source integrations. For that field, Pulsed Laser Deposition (PLD) is a promising technique since it can provide high-quality materials and micro-structuration without etching [1].

In this topic, we want to fully explore the potential of this method by integrating different PLD materials [2] and doping [3] on the same chip. Integrated ring lasers will be studied mainly with Al₂O₃ host [4,5] but with different doping. Using lift-off based processing, several lasers with different wavelengths will be integrated on the same waveguide with a grating coupler for the light injection. Indeed, lift-off based PLD processing offers the possibility to integrate both doped rings at the same level without etching and complex integration. This project will highlight thus the high potential of this method for multiple micro-devices integration on the same chip mainly for sensing applications.

Devices requirements and state of the art comparison for sensing applications will be studied in strong collaboration with Hemara company.

References:
[1] Gassenq et al., Opt. Express, 2021, https://doi.org/10.1364/oe.416450
[2] Jelínek et al., Laser Phys., 2009, https://doi.org/10.1134/s1054660x09020194
[3] Gassenq et al., Appl. Phys. A, 2023, https://doi.org/10.1007/s00339-023-06549-6
[4] Hendriks et al., Adv. Phys. X, 2021, https://doi.org/10.1080/23746149.2020.1833753
[5] Rönn et al., Nat. Commun., 2019, https://doi.org/10.1038/s41467-019-08369-w

Dr. Alban GASSENQ
Arnan Mitchell

Photonics, Integrated Optics, Opto-electronics, Nano and micro-technology