I study light-matter interaction on an attosecond (1 as = 10-18 s) timescale with a focus on strong-fields in condensed matter.
Attosecond science is uniquely capable of resolving the rapid motion of electrons.
Studying attosecond electron motion in condensed matter will have a major impact in light-matter interactions, namely quantum and nonlinear optics, photonics, electro-optics, condensed matter physics, and materials science.
Developing technologies that have unprecedented sensitivity to attosecond electronic motion in external electric fields have potential applications not only for next-generation electronics, electrical engineering, and photonics, but also for molecular detection, standoff detection, and biosensing.
Current Research
We are currently investigating nonlinear pulse propagation through various materials to understand self-phase modulation, photoionization, and self-focusing. Our goals for this research is to develop compact and efficient ways to generate few-cycle pulses for ultrafast measurements. Theory, simulations, and experiment all work together to help us find materials with interesting properties to maximize bandwidth and minimize dispersion.
We are also interested in extending four-wave mixing to the femtosecond regime at high intensities, called Kerr instability amplification. We have found this to be a highly versatile method for amplifying pulses across a very broad (octave spanning) spectrum. We aim to parametrically amplify extremely weak signals generated by other light-matter interactions to map out the femtosecond response in various materials. We have been investigating this nonlinear amplification process for pulse compression and spectroscopy by developing both simulations and experiments.
Recent Publications
S. Ghosh, N. G. Drouillard, and TJ Hammond, "Supercontinuum amplification by Kerr instability," Phys Rev A 109 043508 (2024) https://doi.org/10.1103/PhysRevA.109.043508
- S. Ghosh, N. G. Drouillard, and TJ Hammond, "Single-stage few-cycle pulse amplification," Phys Rev A 109 013511 (2024) https://doi.org/10.1103/PhysRevA.109.013511
- N. G. Drouillard and TJ Hammond, "Measurement of dispersion and index of refraction of 1-decanol with spectrally resolved white light interferometry," Optics Express, 30 39407 (2022) http://doi.org/10.1364/OE.473178
- J. A. Stephen, C. J. Arachchige, and TJ Hammond, "Spectral broadening for pulse compression using liquid alcohols," Journal of Physics B: Atomic, Molecular, and Optical Physics 55 155402 (2022) http://doi.org/10.1088/1361-6455/ac7990
- C. J. Arachchige, J. A. Stephen, and TJ Hammond, "Amplification of femtosecond pulses based on χ(3) nonlinear susceptibility in MgO," Optics Letters, 46 5521-5524 (2021) http://doi.org/10.1364/OL.437749