The Master at the university of Claude Bernard Lyon 1, is a new track launched recently (~2022). The program is mostly dedicated to Optics and Photonics (OPHO). The program offers various courses mainly:

• Quantum and non-linear optics: Quantification of the Electromagnetic fields, Light nature and Photons statistics, Non-linear Optics process (SFG, SHG, THG ...) etc.
• Ultrafast optics: Ultrafast Dynamic, Autocorrelation; Frequency Resolved Optical Gating (FROG) and probe-pump measurements, Femtosecond Chirped Pulse Amplification (CPA) etc.
• Artificial intelligence: Supervised Machine Learning (Regression & Classification), Neural Network and Convolutional Neural Network ...

The Master has been renamed as "Physics of quantum and soft condensed matter (PhyQS)". The program is highly diverse and unique. The lectures cover materials' electronic structure, optical, magnetic properties, and their applications on the nanometer scale, while tracking recent advancements in the fields of nanophysics. The program has three main pillars hovering around solid-state physics:

• Advanced Quantum Mechanics: Quantum theory of diffusion; Landauer-Büttiker approach for the conductance of coherent systems; Kubo formalism and linear response theory for quantum electronic transport; graphene...
• Advanced Statistical Physics: Non-equilibrium statistical physics and transport phenomena: Brownian motion (concept of “coarse-graining”); Markov processes (Fokker-Planck and Langevin equations...); linear response theory (fluctuation-dissipation theorem & Kramers-Kronig relation).
• Light and Matter Interaction: Linear response of a material medium to an electromagnetic excitation; semi-classical approximations and optically induced transitions between electronic states of matter (Franck–Condon) ...

Here marks the beginning of my journey. After three years of studying fundamental physics, I decided to pursue a master's degree in Materials Physics. During this phase, I acquired a robust foundation in solid-state physics. Furthermore, the track I selected was focused on Semiconductors and Dielectric Materials. The program aimed to prepare future materials science researchers, encompassing both experimental and theoretical aspects. The master's program offered a range of lectures, and I will highlight a few of them:

• Physics of Condensed Matters
• Elastic Waves in Fluids and Solids
• Dielectric and Magnetic Properties of Materials
• Advanced Optics and Laser Physics
• Transport Phenomena in Semiconductors
• Materials Characterization

Borophene is a 2D material that has honeycomb structures similar to graphene. Borophene exists in various structures called allotropes. Furthermore, to characterize such materials, a Scanning Tunneling Microscope (STM) is generally used. However, the process is not straightforward and involves comparing experimental data to theoretically simulated images generated from Density Functional Theory (DFT). Although DFT is accurate, it is time-consuming. The intended purpose is to utilize an existing Neural Network Potential (NNP) to create a database of structures and simulated STM images for training and testing a classification neural network.

Borophene Allotropes

High dimensional neural network architecture

Energies & Forces-normes validations

In order to study the kinetics of molecules and probe their optical properties, we employ spectroscopy, which enables us to perform transient absorption and observe the signatures of rapid photo-reactions (e.g., carbon-carbon double bond isomerization) occurring on picosecond or sub-picosecond timescales. However, achieving this requires a well-characterized laser pulse, which means full access to temporal and spectral profiles. Unfortunately, electronic measurement does not accommodate the rapid oscillation of the electric field (few cycles). Here, we call for indirect optical characterization, such as using Frequency Resolved Optical Gating (FROG). For this work, we deployed Time Domain Ptychography techniques to solve a reconstruction problem, in particular, spectral phase retrieval. I implemented the Time Domain Ptychography algorithm to characterize the ultrashort pulses.

Frequency Resolved Optical Gating (FROG)

Retrievement of the pulse profile/phase.

The retrieved 2D FROG map difference between measured & reconstructed spectra.

In order to study the kinetics of molecules and probe their optical properties, we employ spectroscopy, which enables us to perform transient absorption and observe the signatures of rapid photo-reactions (e.g., carbon-carbon double bond isomerization) occurring on picosecond or sub-picosecond timescales. However, achieving this requires a well-characterized laser pulse, which means full access to temporal and spectral profiles. Unfortunately, electronic measurement does not accommodate the rapid oscillation of the electric field (few cycles). Here, we call for indirect optical characterization, such as using Frequency Resolved Optical Gating (FROG). For this work, we deployed Time Domain Ptychography techniques to solve a reconstruction problem, in particular, spectral phase retrieval. I implemented the Time Domain Ptychography algorithm to characterize the ultrashort pulses.

Manufactured m-Si solar cell (before screen printing)

Manufactured m-Si solar cell (after screen printing) with Al leads (contacts)

Dissipated Power in the shunt, the series resistance and in the forward bias diode.

Current Analysis of losses due to reflection and parasitic absorption.