Actively stabilized isolator-free ultranarrow linewidth III-V-on-Si lasers for short-reach optical interconnects
PhD - Gent | More than two weeks ago
Expand imec's photonics technology by developing ultrastable III-V-on-silicon lasers
On-chip III-V-on-Si lasers with very ultranarrow linewidth have recently been demonstrated, leveraging the integration of III-V materials in a low loss Si/SiN platform. Such lasers are in high demand for a wide variety of applications such as telecom/datacom, optical sensing, microwave and quantum photonics thanks to their extremely low-noise and high coherence. A narrow linewidth laser is typically shielded from external reflections by an optical isolator (OI) in the laser package. 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. This is even more challenging in the context of multi-wavelengths light sources on chip that are needed for dense wavelength-division multiplexing (DWDM) in short-reach optical interconnects.
The goal of the proposed PhD is to investigate actively stabilized isolator-free ultranarrow linewidth III-V-on-Si lasers developed in imec’s Si/SiN 200-300 mm photonic platforms using an opto-electronic feedback loop. The PhD student will also carry out the design of laser diodes naturally less sensitive to external reflections such as quantum dot lasers. This work is expected to result in the demonstration of multi-wavelength light sources bypassing the need of an OI and with a much narrower linewidth than in the case of a free-running laser shielded by an OI. Those multi-wavelength light sources will find their way in a broad range of applications and are particularly appealing for datacenters.
What you will do
Over the course of the PhD, your work will cover all aspects of research, from optical simulations and laser design, fabrication of heterogeneously integrated lasers in a clean room, to electro-optical characterization of fabricated devices. Focus will be on the characterization of fabricated devices and on the development and demonstration of an opto-electronic feedback system to maintain a narrow laser linewidth under varying external optical reflections. This will involve some system integration and electronics work. You will learn about the design of advanced III-V-on-Si/SiN lasers, their fabrication and their characterization. You will gain experience in advanced characterization techniques for measuring laser linewidth and intensity noise, as well as assembling laser modules that include electronics components on printed circuit boards. This PhD will encompass everything from design to assembly of laser modules for real applications.
What imec will offer you
Working at imec as a PhD student will bring you:
- Going from design, fabrication process to demonstration/characterization
- Access to state-of-the-art technology through imec 200-300 mm pilot CMOS lines and a connection with semiconductor industry
- Contact with applications in fields such as optical communications, lidar and optical sensing
Who you are
- You hold a MSc degree in Applied Physics, Electrical Engineering, or Optical Engineering
- You have a strong interest and background in photonics, but you also have a strong background in electronics and systems.
- You have a good knowledge of Python/MATLAB.
- Hands-on experience on an optical setup would be a plus.
- Autonomy, scientific curiosity, and ability to work in an international environment
- A strong commitment towards your work is expected
Type of work: 10% literature study, 35% modeling/simulation, 20% fabrication, 35% characterization
Supervisor: Geert Morthier
Daily advisor: Charles Caer
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: Charles Caer
The reference code for this position is 2023-005. Mention this reference code on your application form.