Research

Passive photonic circuits can only take you so far. At some point, every optical system reaches the same limit: you wish you had more light, more control, or a way to generate and shape the field directly on chip. My work in active photonics aims to fill this gap.

Active photonics spans amplifiers and lasers across a range of material platforms, including III-V semiconductors and rare-earth systems. I am particularly interested in treating gain not as a standalone source coupled to a photonic chip, but as an integrated building block within photonic circuits. In the case of mid-infrared QCLs, this approach has enabled active resonators, tunable ring and racetrack lasers, and on-demand sources of pulsed light. Similar concepts, translated to the near-infrared, could help address bottlenecks in high-speed communications, including data-center and undersea links.

Relevant papers

The mid-infrared, broadly defined here as 3-12 µm, is one of the richest regions in optics because many molecules have strong, distinctive spectral fingerprints there. My work in sensing is driven by the challenge of turning that spectral richness into compact, fast, and practical systems using QCLs, either as single-mode tunable lasers for identifying narrow absorption features or as dual-comb spectrometers that cover broad spectral ranges in microseconds.

Much work is still needed to realize these devices. Future work aims to combine the necessary electronics and photonic components, including drivers, sources, detectors, and optical circuitry, on a single chip.

Relevant papers

Lasers are often thought of as sources that emit a single color of light, but that is not always the case. Under the right conditions, a laser can emit many evenly spaced colors at once, and if these colors remain phase-locked they form what is known as an optical frequency comb. Frequency combs are useful for applications ranging from precision spectroscopy and chemical sensing to metrology, timing, and optical communications.

A major theme of my work is understanding how these coherent multi-frequency states emerge in III-V semiconductor lasers. Because these systems have ultrafast gain dynamics, they can spontaneously form mode-locked and comb-like states, along with other structured nonlinear dynamics such as solitons and soliton pairs. I am interested both in the physics of how these states arise and in how they can be engineered in more complex laser geometries, including coupled and actively driven resonators.

Relevant papers