PhD defense Shirley Prado de la Cruz: Semi-Insulating Buried Heterostructures integration approaches and building blocks for next generation of transceivers on InP
Auditorium de Thales TRT, III-V Lab 1 Av. Augustin Fresnel, F-91120 Palaiseau
Jury
- Frédéric Grillot, Professeur, Télécom Paris, France (Thesis Supervisor)
- Vladyslav Vakarin, Docteur – Ingénieur, III-V Lab, France (Co-supervisor in industry)
- Sophie Bouchoule, Directeur de Recherche, C2N, France (Reviewer)
- Olivier Gauthier-Lafaye, Directeur de Recherche, LAAS-CNRS, France (Reviewer)
- Eric Tournié, Professeur, Université de Montpellier, France (Examiner)
- Adel Bousseksou, Maître de conférences, Université Paris-Saclay (C2N), France (Examiner)
- Guilhem Almuneau, Directeur de Recherche, LAAS-CNRS, France (Examiner)
Abstract
Data traffic has significantly increased in recent years and is expected to keep rising due to bandwidth-intensive services such as Artificial Intelligence (AI) and high-definition gaming. One approach to enhance transmission data rates is to develop transceivers based on photonic integrated circuits (PICs), which are the key elements responsible for transmitting and receiving signals in Passive Optical Networks (PONs). The fundamental components forming a PIC, known as building blocks (BBs), are the focus of this work.
Three approaches were investigated to improve the transmission capabilities of next-generation transceivers. The first concerns the development of SIBH technology used for the fabrication of active BBs. A one-step SIBH structure incorporating a blocking layer was developed. Several studies were conducted to evaluate the influence of growth temperature and layer thickness, with the optimal parameters identified as a growth temperature of 520 °C and a thickness of 40 nm. Additional investigations were also carried out on alternative materials for the semi-insulating layers of the SIBH structure, such as InP:Be and InP:Ru.
The second approach focuses on passive BBs. Fabrication processes were developed to enable the monolithic integration of passive and active components despite their two different waveguide architectures (SIBH and deep-ridge). The main challenge encountered was the formation of polycrystals due to the SIBH regrowth, resulting in propagation losses exceeding 10 dB/cm for 1.5 µm deep-ridge waveguides. This issue was successfully resolved using an improved second fabrication process.
Finally, a new InP (de)multiplexer structure based on a tilted angled multimode interferometer (AMMI) was developed. The device exhibits a compact footprint of 0,09 mm2, a crosstalk level of 14.35 dB, and an insertion loss of 8 dB.