Research Projects

 
PULSE.jpg

Publications

No publication yet

PULSE : Plastic UltraFast Lasers
ongoing project

The objective of the ANR project PULSE (for Plastic Ultrashort LaSErs), started in 2021, is to demonstrate the possibility of obtaining laser operation in unprecedented temporal regimes, namely  an ultrashort pulse regime with high repetition rates . We will thus seek to produce the first mode-locked organic semiconductor laser.

 

 

Global strategy consists in implementing recently developed organic materials in innovative laser architectures. Achieving this goal requests adressing two important challenges. The first one is linked to the piling up of triplet excitons, which prevents organic lasers from operating in the CW regime, which in turn does not allow for a stable mode-locking regime to set up. Second challenge is to find an adequate saturable absorber. To solve these two issues, novel materials have been identified.

Collaborations

This project is a collaborative work between the Organic Photonics group at Laser Physics Lab (S. Chénais, S. Forget) in Université Sorbonne Paris Nord (Villetaneuse), and the Laser Group at Laboratoire Charles Fabry (LCF), Institut d’Optique Graduate School (P. Georges, F. Druon) in Saclay. Other collaborations in relation with this project are also active with several groups of chemists in France and the Adachi group in Kyushu University, Japan.  

Funding : ANR 2020-2024

Diapositive5.JPG

Publications

No publication yet

NEW LIGHT : building the new generation of luminescent concentrators for illumination
ongoing project

An LED-pumped luminescent concentrator (LC) is a parallelepiped-shaped luminescent material with LEDs on its large sides. After absorbing light from the LEDs, the material re-emits light into the LC which is guided to its edges. Concentration is achieved through total internal reflections. This leads to a luminance 10 to 20 times higher than that of the LEDs. This is an emerging field of research with a very high disruptive potential.

 

The aim of the NewLight project is to develop concentrators over a large part of the optical spectrum (visible SWIR-short-wavelength infrared- and MWIR-medium-wavelength infrared) with a systematic, multidisciplinary approach, combining materials and systems.

Collaborations :

Laboratoire Charles Fabry (LCF), Institut d'Optique, Université Paris Saclay

Institut de Recherche de Chimie Paris (IRCP)

Institut des Sciences Chimiques de Rennes (ISCR)

Funding : ANR 2021-2025

IMG_8995.JPG

Publications

​Y. Hu, F. Bencheikh, S. Chénais, S. Forget, X. Liu, and C. Adachi
High Performance Planar Microcavity Organic Semiconductor Lasers Based on Thermally Evaporated Top Distributed Bragg Reflector
Applied Physics Letters – Editor’s pick - 117, 153301 (2020)

 

A.Hamja, S.Chénais and S.Forget,
Temporal dynamics of diode-pumped circulation-free liquid dye lasers
Journal of Applied Physics 128, 015501 (2020)

New organic sources : towards Continuous-Wave organic lasers and organic polariton devices
ongoing project

This project aims at pushing organic lasers beyond today’s limits in terms of temporal regimes in order to make them compatible with a much wider range of applications. Our main objective will be to seek True continuous-wave operation in a Vertical Cavity Resonator, establishing guidelines for the choice of new materials and device structures. Attaining such a regime will unlock the possibility for ultrafast pulse generation, and will open the way towards electrical pumping.

Collaborations :

Opera Lab (Kyushu University, Japan)

Fundings :  BQR Sorbonne Paris Nord, ERATO Project (Japan)

IMG_8821.JPG

Publications

T. Ishii, F. Bencheikh, S. Forget, S. Chénais, B.Heinrich, D. Kreher, L. Sosa Vargas, K. Miyata, K. Onda, T. Fujihara, S. Kéna-Cohen, F. Mathevet, and C. Adachi“Enhanced light-matter interaction and polariton relaxation by the control of molecular orientation”Advanced Optical Materials (2021)

MELODIE : searching innovative materials for the organic laser diode
ongoing project

In this project, our ambition is to combine for the first time theoretical calculations of triplet absorption bands, chemical synthesis of both small and macromolecules, as well as photophysical characterizations in order to realize a screening of novel molecular structures and identify new candidates for electrically-pumped organic lasers covering the whole visible spectrum.

Collaborations :

Institut Parisien de Sciences Chimiques (F.Mathevet)

Opera Lab (Kyushu University, Japan)

Fundings :  IEA CNRS

Diapositive6.JPG

Publications

T. Gallinelli, A. Barbet, F. Druon, F. Balembois, P. Georges, T.Billeton, S. Chénais and S. Forget
Enhancing brightness of Lambertian light sources with luminescent concentrators: the light extraction issue
Optics Express Volume 27, issue 8, Pages 11830-11843 (2019)

 

P. Pichon, A. Barbet, D. Blengino, P. Legavre, T. Gallinelli, F. Druon, J.-P. Blanchot, F. Balembois, S. Forget, S. Chénais, P. Georges
High-radiance light sources with LED-pumped luminescent concentrators applied to pump Nd:YAG passively Q-switched laser”,
Optics and Laser Technology, Volume 96, Pages 7–12 (2017)

 

A.Barbet, A. Paul, T. Gallinelli, F. Balembois, J-P. Blanchot, S. Forget, S.Chénais, F.Druon, and P. Georges,
LED pumped luminescent concentrators: a new opportunity for low cost solid-state lasers
Optica 3, 465-468 (2016)

EDELVEIS 
Completed project

The goal of the EDELVEIS projectwas to develop new tunable lasers in the visible (organic materials) and in the near infrared (bulk crystals including Ti:saphirre crystals). These laser systems will combine simplicity and compacity at an ultra low cost compared to today laser sources, thanks to the LEDs as pump sources.

Differents results have been obtained during the project :

 

- first demonstration of a LED pumped Nd:YVO4 laser,

- first demonstration of an indirect LED pumped laser with a light concentrator,

- first demonstration of a LED pumped alexandrite laser.

At LPL, our main contribution was the developpment of luminescent light concentrators (characterisation and modelling essentially)

Collaborations :

The project Leader is Laboratoire Charles Fabry at the Institut d'Optique Graduate School (F.Balembois). Effilux Company was also involved in this study.

Funding : ANR (2012-2016)

vecspresso orange7.jpg

Publications

O. Mhibik, S. Chénais, S. Forget, C. Defranoux, S. Sanaur,
Inkjet-printed vertically-emitting solid-state organic lasers
Journal of Applied Physics, 119, 173101 (2016)

 

O. Mhibik, S. Forget, D. Ott, G. Venus, I. Divliansky, L. Glebov and S. Chénais
An ultra-narrow linewidth solution-processed organic laser
Light: Science & Applications 5, e16026 (2016)

Z.Zhao, O.Mhibik, M.Nafa, S.Chenais and S. Forget,
High brightness diode pumped organic solid-state laser
Appl. Phys. Lett. 106, 051112 (2015)

 

Z.Zhao, O.Mhibik, T.Leang, S. Forget and S.Chenais,
Thermal effects in thin-film organic solid-state lasers
Optics Express Vol. 22, Issue 24, pp. 30092-30107 (2014)

O.Mhibik, T.Leang, A.Siove, S. Forget and S.Chénais,
Low-cost broadly tunable (440-670 nm) solid-state organic laser with disposable capsules
Appl. Phys Lett.  102, 041112 (2013)

VECSPRESSO : solid-state dye lasers with disposable capsules
Completed project

Do you prefer a strong, powerful red laser or a smooth, delicate blue laser with a soft degradation finish ? Pick up the good capsule and travel to your favorite part of the optical spectrum !

Collaboration :

CREOL, Orlando (USA)

Mines de St Etienne

Fundings : ANR "emergence", 2012-2015

exciton diffusion.jpg

Publications

M. Lebental, H. Choukri, S. Chénais, S. Forget, A. Siove, B. Geffroy et E. Tutis
Diffusion of triplet excitons in an operational Organic Light Emitting Diode
Physical Review B, 79, 165318 (2009)

Triplet Diffusion in OLEDs
Completed project

In this project, we moved a thin sensing layer inside a working OLED to probe the triplet diffusion length. A theoretical model was also applied and the interplay of microcavity effects and direct recombinations is demonstrated experimentally.

Collaboration :

Institut of Physics, Zurich (E.Tutis)

CEA Saclay (B.Geffroy)

Fundings : C'nano Ile de France

zoom.jpg

Publications

H. Rabbani-Haghighi, S. Forget, A. Siove and S. Chénais
Analytical study of vertical external-cavity surface-emitting organic lasers”
The European Physical Journal Applied Physics, 56 , 34108 (2011)

S. Forget, H.Rabbani-Haghighi, N.Diffalah, A.Siove, S.Chenais
Tunable Ultraviolet Vertically-emitting Organic Laser
Applied Physics Letters, 98, 131102 (2011)

H. Rabbani-Haghighi, S. Forget, S. Chénais, A. Siove
Highly-efficient, diffraction-limited laser emission from a Vertical External Cavity Surface-emitting Organic Laser
Optics Letters Vol. 35, Iss. 12, pp. 1968–1970 (2010)

BACHELOR : Building Architectures for Organic Lasers
Completed project

We propose a new kind of architecure for organic laser resonators, namely a Vertical External Cavity Surface emitting Organic Laser. Alongside with enhanced performances (diffraction limited beam, record efficiency tahnks to longitudinal pumping), this geometry allows a great versatility. Being very modulable (mirrors, cavity length, intracavity elements), it is a very nice toy to unravel the mysteries of organic lasers !

Fundings : ANR "young researcher", 2009-2010

Lumen_OLEDs.jpg

Publications

H. Choukri, A. Fischer, S. Forget, S. Chénais, M-C Castex, D. Adès, A. Siove, B. Geffroy
Doped and non-doped organic light-emitting diodes based on a yellow carbazole emitter into a blue-emitting matrix
Synthetic metals – 157 pp.198-204 (2007)

 

H. Choukri, A. Fischer, S. Forget, S. Chénais, M-C Castex, D. Adès, A. Siove, B. Geffroy
White Organic Light-Emitting Diodes with fine chromaticity tuning via ultrathin layer position shifting
Applied Physics Letters, 89, 183513 (2006)

 

A.Fischer, S. Chénais, S. Forget, M.-C. Castex, D. Adès, A. Siove, C. Denis, P. Maisse and B. Geffroy,
Highly efficient multilayer organic pure blue light emitting diodes with substituted carbazoles compounds in the emitting layer
Journal of Physics D : Applied Physics  vol 39 pp. 917-922 (2006)

Color control of OLEDs
Completed project

With this project we develop several OLEDs in collaboration with CEA at Saclay, from a state to the art blue fluorescent diode to a red one using new efficient red dyes. A funny part of the project was to design an OLED cavity, playing on the intracavity optical field profile, the singlet diffusion depth and two complementary colors to produce a nice White OLED.

Collaboration :

CEA Saclay

Here is a brief selection of our ongoing and completed research projects. We refer as a "project" a research action which involves at least some specific associated funding and collaborations. This means some of our research interests (presented in the research topics page might not be found here. Most of our research projects are related to organic lasers, but not all. Projects highlighted as "completed" are not active any more now ; but some of them are continued through one or several ongoing projects.