PhD - Leuven | More than two weeks ago
On-chip III-V-on-Si lasers with low-noise and narrow linewidth have recently been demonstrated, leveraging the integration of III-V materials in a low loss Si/ platform. Such lasers are in high demand for a wide variety of applications such as optical fiber communications, optical sensing, microwave, and quantum photonics thanks to their extremely low-noise and high coherence. A high-performance laser is usually vulnerable to external reflections and required an optical isolator (OI) to shield it from unwanted optical feedback. However, the OI cannot be integrated with the laser in a photonic integrated circuit (PIC), leaving the on-chip laser vulnerable to parasitic optical feedback coming from various photonic devices on the PIC, while increasing costs and complexity when adding the OI to the package.
The goal of the proposed PhD is to investigate actively stabilized isolator-free low-noise narrow linewidth multi-wavelength III-V-on-Si lasers using an opto-electronic feedback loop. The student will be able to use Si/ 200- photonic platforms for the III-V-on-Si integrations. The PhD student will also design laser diodes naturally less sensitive to external reflections such as quantum dot lasers and tunable lasers toward DWDM requirement. This work is expected to result in the demonstration of multi-wavelength III-V-on-Si lasers bypassing the need of an OI while maintaining low-noise and narrow linewidth performance.
What you will do
Over the PhD, your work will cover all aspects of research, from optical simulations and laser design, PIC fabrication of heterogeneously integrated lasers in a clean room, to electro-optical characterization of fabricated devices. Focuses will be on the characterization of fabricated devices and on the development and demonstration of an opto-electronic feedback system to maintain laser with low-noise and narrow linewidth under varying external optical reflections. This will involve some system integration and electronics work. You will learn about the design of advanced -on-Si lasers, their fabrication, and their characterization. You will also gain experience in advanced characterization techniques for measuring laser frequency and intensity noises, as well as assembling laser modules that include electronic components on printed circuit boards. This PhD will encompass everything from design to assembly of laser modules for real applications.
Required background: MSc degree in Applied Physics, Electrical Engineering, or Optical Engineering
Type of work: 10% literature study, 35% modeling/simulation, 20% fabrication, 35% characterization
Supervisor: Geert Morthier
Daily advisor: Hsiao-Lun Wang
The reference code for this position is 2024-010. Mention this reference code on your application form.