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Thursday 26th of september 2019, 2:00 pm, INSA Rennes

Salvatore PES defends his PhD thesis

« Nanostructures-based 1.55 μm emitting Vertical-(External)-Cavity Surface-Emitting Lasers for microwave photonics and coherent communications »

V(E)CSELs, quantum dashes, tunable devices, liquid crystals, bi-frequency lasers


The work presented in this dissertation focus on the development of InP-based semiconductor vertical-cavity lasers, based on quantum nanostructured and emitting at the telecom wavelengths (1550-1600 nm). A new technological process for the realization of compact VCSEL is described. This process (named TSHEC) has been employed to realize optically-pumped VCSELs, integrated on a host Si-platform, with good performances. The same process has been adapted to develop an electrically-driven version of VCSEL: a preliminary study of the confinement section based on InGaAs-BTJ is presented, together with the development of a mask set. Thanks to the development of the LC µ-cell technology (in collaboration with LAAS, IMT Atlantique et C2N), we realized a tunable photodiode at 1.55 µm, and a tunable VCSEL is currently under development. This work also presents the first realization of a 1.6 µm-emitting optically-pumped quantum dashes-based VECSELs, and its characterization in multi-mode and single frequency regime. Finally, the realization of an experimental setup for the investigation of the coupling between two orthogonal eigenstates of a bi-frequency 1.54 µm-emitting SQW-VECSEL has been conceived and realized. This setup, which allowed the direct quantification of the coupling constant on such a device, in the near future will allow performing the same study on anisotropic structures like quantum dashes or quantum dots, with the objective of studying the inhomogeneous broadening effect observed in these gain regions.

(a) Scheme of the investigated electrically-pumped VCSEL obtained by the TSHEC process (inset: SEM photo of a test device), (b) Structure of the 1.6 µm-emitting VECSEL based on quantum dashes nanostructures (inset: AFM photo of a quantum dashes layer), (c) Experimental setup used to investigate the coupling constant in dual-frequency VECSELs
Committee members
Isabelle SAGNES Director of research, C2N, CNRS, FranceExaminator
Daniel DOLFI Director of Physics Group, TRT, FranceExaminator
Mircea GUINA Professor, TUT, FinlandMember
Stéphane CALVEZ Researcher , LAAS, CNRS, FranceMember
Philippe ADAM Person in charge of photonics , DGA-MRIS, FranceInvited
Cyril PARANTHOEN Assistant Professor, Institut FOTON, INSA Rennes, FrancePhD Manager
Mehdi ALOUINI Professor, Institut FOTON, Rennes University, France PhD Supervisor
Hervé FOLLIOT Professor, Institut FOTON, INSA Rennes, FrancePhD Supervisor