1. JULIEN
LE CLEC'H
Multidisciplinary
ENGINEER
o 30 years old
o French nationality
o Work permit B
o Driving license B
Profile, Professional Ambitions
Multidisciplinary young engineer, with 8 years of working experience, as a Researcher, a
Research Engineer and as an Application Engineer.
I would like to get the opportunity to improve my skills through different fields of activities,
by facing new challenges, and by meeting new people.
I am also interested in developing my management responsibilities, and in sharing my former
experiences, to give you the opportunity to benefit from my expertise.
Education
o 2011 Laureate "24 heures chrono de
l'entrepreneuriat"
- ADVANCIA, Business school | ANRT – Paris
o 2008-2012 PhD-Student in Physics
Material Sciences field of study
- Matter, Molecules, Materials in Pays de la Loire Doctoral School
o 2007-2008 Research Master level 2
Materials, Matter & Components
- University of Nantes, Faculty of Sciences et Techniques
o 2005-2008 Engineering studies
Material Sciences, R&D specialization
- Polytech Nantes, Nantes University Engineering Graduate School
Career History
o 2014 – Present Application Engineer
Synova S.A. | Lausanne (CH)
o 2008 – 2014 Research Engineer
3S Photonics | Nozay (FR)
o 2008 – 2008 Researcher
Max Born Institute | Berlin (DE)
o 2007 – 2008 Research Student
MHS Electronics | Nantes (FR)
o 2007 – 2007 Research Assistant
Faculty of Forestry | Toronto (CA)
Computer Skills
o Office software Microsoft Office, …
o Scientific JMP, OriginLab, Zemax, …
o Programming VBA, C++, G-Code, …
o MDA – CAD/CAM AutoCad, SolidWorks, Catia, AlphaCam, …
o FEM Comsol, Ansys, …
Linguistic proficiency
o French Native language
o English C2 (CECR)
o German B1 (CECR)
Technical & Scientific Skills
o 5-axis machines optimization
o Development, technical validation of process & products
o Customer request analysis / Feasibility demo
o Back-up supplier search & validation
o Technical & Quality audit of suppliers
o First Article Inspection
o Cost optimization / yield improvement
o On-site operator training
o Equipment Maintenance
o DEO, FEM modeling
o Material characterization
Alicona, MEB, nano-SIM, Micro-Thermographie IR, …
o Flexibility, Autonomy, Multitasking
o Team work, inter-department collaborations
o Scientific publications & talks, technical reporting
Chemin de la Prairie 5D
CH-1007, Lausanne
0041 78 793 23 90
julienleclech@gmail.com
https://ch.linkedin.com/in/julienleclech

2. Contributions & Collaborations
Julien LeClecH, Mathias Ziegler, Jayanta Mukherjee, Jens W. Tomm, Thomas Elsaesser, Jean-Pierre Landesman, Brian Corbett,
John G. Mclnerney, Johann Peter Reithmaier, Stefan Deubert, Alfred Forchel, Włodzimierz Nakwaski, and Robert P. Sarzała,
« Microthermography of diode lasers : The impact of light propagation on image formation », Journal of Applied Physics, vol.
105, no
1, janvier 2009.
Jayanta Mukherjee, Mathias Ziegler, Julien LeClecH, Jens W. Tomm, Brian Corbett, John G. McInerney, Johann Peter
Reithmaier, S. Deubert and A. Forchel, « Bulk temperature mapping of broad area quantum dot lasers: modeling and micro-
thermographic analysis », Proc. SPIE 7230, 72300W, San Jose (CA, USA), janvier 2009.
Julien LeClecH, D. T. Cassidy, M. Biet, F. Laruelle, M. Bettiati et J.-P. Landesman, « GaAs-based laser diode bonding-induced
stress investigation by means of simulation and degree of polarization of photoluminescence measurements », EuroSimE
Proceedings 2010, IEEE Catalog number CFP10566-CDR, ISBN 978-1-4244-7025-9, Bordeaux, avril 2010.
Julien LeClecH pour 3SP, LPICM, HJB, CEA-LETI et STM, « ContRam Project », Journées Nationales en Nanosciences et en
Nanotechnologies (J3N - Pnano), Lille, novembre 2010.
Julien LeClecH, D. T. Cassidy, F. Laruelle, M. Bettiati et J.-P. Landesman, « Physical modeling of mechanical and thermal
properties of 980nm high-power laser diodes on composite submounts », Lasers and Electro-Optics Europe (CLEO
EUROPE/EQEC), 2011 Conference on and 12th
European Quantum Electronics Conference, Munich, mai 2011.
Julien LeClecH, D. T. Cassidy, F. Laruelle, M. Bettiati et J.-P. Landesman, « Residual mechanical stress decrease in GaAs-based
laser diodes via a bi-material submount investigation », Proc. SPIE 8080, 808006 (2011), SPIE Optics + Optoelectronics
Proceedings 2011, Prague, avril 2011.
French project ContRam number ANR-09-NANO-041-05, in pertnership with le Laboratoire de Physique des Interfaces et
Couches Minces (LPICM) de l’école Polytechnique de Palaiseau, Horiba Jobin Yvon GmbH, le Laboratoire d’Électronique des
Technologies de l’Information (CEA-LETI), ST Microelectronics and 3SPhotonics.
Julien LeClecH, “Physical Study of High-Power Laser Diodes: Stress, Thermal Management, and Reliability”, PhD Thesis,
Université de Nantes, UFR de Sciences et Techniques, Polytech Nantes, February 2012.
Abstract:
Mechanical stress in high-power single-mode pump GaAs-based laser diodes emitting at 980 nm has been studied. The goal is
twofold: first of all an understanding of the origin of the stress generated in laser diodes is needed, to then be able to manage
this induced stress when manufacturing laser modules. In this document, we focus on the stress generated when soldering a
laser diode on its submount.
In fact, it appears that the submount itself, the pick-and-place tool used, and the thermal conditions set for the brasing cycle
play a crucial role in the manufacturing of high-performance and reliable devices, via the induced stress management.
Thereby, we show in this document, that it is possible to design a bi-material submount, generating a low and homogeneous
stress level in laser diodes, and preserving the thermal and electrical characteristics offered by efficient submounts. We also
discuss the stress applied to the laser diode by the pick-and-place tool, with respect to its surface state, and we show the link
between the laser diode profile and the solder joint integrity. Finally, we also address the topic of soldering parameters via
successive series of tests, highlighting the optimal conditions to be set in terms of temperature and duration of brasing cycle, in
terms of applied force on laser diodes, and in terms of metallic vertical structure of the submount.
Keywords:
Laser diodes on submounts, packaging of high-power optoelectronic devices, thermo-mechanical stress, reliability, numerical
simulation, FEM calculation, metallurgy.