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photochromic thin films for optical neuromorphic computing

photochromic thin films for optical neuromorphic computing

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Stage M2
France
March 2 2026
February 2 2026
4 month
2025-photochromic-thin-films-for-optical-neuromorphic-c-en

Domain, Specialties : Condensed matter physics
Keywords: Photonics, Material science

Research Unit : SPEC/LEPO

Summary

The objective of the internship (M1 or M2) is to characterize the optical switching capabilities of thin photochromic polymer films and to evaluate the feasibility of their implementation as optical synapses for neuromorphic computing.

Full description

This master’s project is part of the PHOTOMIC project, funded by the ANR. This multidisciplinary project explores the use of photochromic materials to create reconfigurable, low-energy photonic synapses. These synapses will be designed to modulate the weights of connections within an artificial photonic neural network.

The main objective of the internship is to implement these photonic synapses, which will involve the fabrication of photo-controllable diffraction gratings. This will require evaluating the optical performance of various photochromic materials. Two potentially synergistic effects will be studied: direct modulation of the refractive index by photoisomerization (using diarylethene derivatives) and fabrication of surface relief gratings following photo-induced mass transport (using azobenzene derivatives).

The intern will be integrated into SPEC/LEPO (CEA-Saclay, site de l’Orme des Merisiers), a research group with extensive expertise at the interface of organic materials, photophysics, nanophotonics, and local probe microscopy. Previous work has led to the selection of various photochromic systems of interest (azobenenes or diarylethenes). An optical bench has also been developed to enable the recording of holograms by photoinduced optical modulation or to test the resulting diffraction properties.

The internship will consist in characterizing the photophysical and optical switching characteristics of thin films of different photochromic polymers. The main tasks will be:

  • Depositing thin films of photochromic polymers.
  • Measuring transient photoinduced index changes in the polymer film.
  • Analyzing the photo-induced patterns formed in the films using either AFM or optical micro-spectroscopy.

Location

CEA Saclay, (91) Essonne, France

Internship conditions

  • Internship duration: 4 months
  • Level of study: Bac+4/5
  • Training: Master 1
  • Continuation in PhD thesis: No
  • Application deadline: 1 mars 2026

Experimental skills

Language : English

Useful methods and technics: Local probe microscopy (AFM), optical microspectroscopy

Computer languages and software: Python

Supervisor

Celine FIORINI
Phone: +33 1 69 08 62 38 / 06 60 49 17 35
Email :

Head of the laboratory

Ludovic Douillard (SPEC/LEPO)