Why light?

When I started my B.Eng. Physics at Carleton University, it was supposed to be a segue into aeronautical engineering. However, I discovered that the flow light was analogous to aerodynamics, that optics had better career prospects, and that B.Eng. Physics was more challenging and interesting. So I completed internships in fiber optic sensing with Prof. Jacques Albert at Carleton, telecommunication devices at JDSU (now Lumentum), nuclear energy with Victor Sanchez at the Helmholtz nuclear institute in KIT, and ultrafast optics with Prof. Roberto Morandotti at INRS-EMT, along with many research and teaching assistantships at Carleton. The results of my last internship won me a Co-op Student of the Year prize at Carleton University in 2015 right before graduating.

I developed a passion for solid-state physics, chip technologies, and optics/photonics.

Why nano-light?

For my M.Eng., I won a SiEPIC scholarship which funded me to work in the field, and this sealed the deal. In 2018, I was invited to attend a Student Leadership Conference by OSA in Washington D.C.

During this time, I was also invited by Prof. Mark Andrews to work with Dan (whom I talk about in For Dan, From Us) to how the shell of a diatom affects its ability to harvest sunlight. This project combined my passions for optics, nature, sustainability, and diving so naturally, I jumped on it. During this time, I was offered to fast-track to a Ph.D. and took the opportunity. Soon after, I competed in a Pechakucha competition (fixed presentation consisting of 20 slides with a duration 20s per slide) with the diatom project, and won!

Our work on diatoms was also featured in Optica, Phys.org, ScienceDaily, AZO Optics, McGill Chemistry, and Physics World as well as my Ph.D. thesis titled…

Harvesting solar energy on a silicon photonic chip

An hour of sunlight can satisfy global power consumption for a year, yet solar energy contributes to only 2% of electricity generation. This gap is due to the high price per watt of capture, conversion, and retention. Solar panels capture only direct sunlight, and it depends on weather conditions. The fraction of the solar spectrum that is converted into electricity is limited by the absorption spectrum of silicon (Si). This electricity is retained in batteries whose capacity is further limited by the fermionic nature of electrons. These limitations on the electrical process of harvesting solar energy made me wonder whether it was possible to design an optical process instead.

My thesis shows that sunlight can be captured into optical modes, retained via the bosonic nature of photons, and transferred to electron kinetic energy. Hence, rather than transferring energy from sunlight to bound electrons and then storing electrical energy, our scheme captures and stores optical energy and then transfers it to free electrons. It employs complementary metal oxide-semiconductor technology to ensure inexpensive mass-manufacturability and leverages the maturity of the Si photonic (SiP) platform to design wavelength-dependent but scale-invariant optical devices. We present this scheme as a SiP circuit consisting of 6 devices which perform the following functions: (i) capture ambient light into confined modes, (ii) split the modes based on polarization, (iii) rotate one polarization, (iv) match the phases, (v) combine them into a single mode, and (vi) transfer the energy to free electrons.

The investigation revealed that solar energy could be harvested optically, and that this process could be used as either a substitute or a complement to the current electrical process. The novel device designs from my thesis already offer direct applications to a variety of fields including telecommunications, sensing, and quantum information science. Their separate applications incentivize further development, which is supported by the modularized design of our circuit. In this context, the thesis provides a starting point on the roadmap towards harvesting solar energy on a SiP chip.

Here is my Ph.D. defence presentation, which summarizes the entire thesis. Enjoy!

And if you’re feeling particularly curious, feel free to read my thesis below…

Key publications

• Harvesting solar energy on a silicon photonic chip (PhD thesis), 2023
• Efficient coupling between free electrons and the supermode of a silicon slot waveguide, 2023
• Solar energy harvesting mechanisms of the frustules of Nitzschia filiformis diatoms, 2022
• Standalone, CMOS-based Faraday rotation in a silicon photonic waveguide, 2022
• Integration of periodic, sub-wavelength structures in silicon-on-insulator photonic device design, 2020
• Compact, Angled Polarization Splitter: Characterization of Broadband Performance and Fabrication Tolerance, 2018
• Silicon-Organic-Hybrid Independent Simultaneous Dual-Polarization Modulator: Device Theory and Design, 2017

The rest are available on my Google Scholar. If you can’t access the pdf, feel free to send me a request.