News

Optica Incubator on Petahertz Electronics. Together with Donnie Keathley (MIT) and Matthias Kling (Stanford University), we are organizing the Optica Incubator on Petahertz Electronics, to be held November 12–14, 2025, at Optica Global Headquarters in Washington, D.C. The incubator will bring together about 60 leading researchers to explore how light-field–driven electronics can push the limits of speed, control, and integration, from ultrafast currents to quantum technologies. Through invited talks and discussions, we aim to develop a roadmap for the emerging field of petahertz electronics. Learn more on optica.org

Otto Hahn Award 2025. Prof. Peter Hommelhoff, Christian’s Ph.D. advisor, received the Otto Hahn Award 2025 in Frankfurt, one of Germany’s highest honors in physics, for his groundbreaking contributions to ultrafast science. The award ceremony was followed by a symposium highlighting recent advances in lightwave-driven electron dynamics and quantum control on attosecond timescales, areas closely connected to the research in our group at UCF. It was great to meet colleagues and friends from the ultrafast physics community and to discuss the exciting developments shaping the future of lightwave electronics.

Great visit today from Gian Luca Dolso (MIT)! We explored attosecond all-optical spectroscopy and discussed exciting new directions in electric-field sampling for uncovering ultrafast electron dynamics in solids and nanostructures. Gian gave an excellent talk sharing his latest results, followed by discussions about the future of attosecond spectroscopy and potential collaborations. Thanks for visiting us, Gian — we’re looking forward to continuing the conversation and exploring joint ideas in lightwave electronics!

Nonresonant Raman Control of Ferroelectric Polarization — now in Advanced Materials! It was a pleasure to work with Jiojian Shi on this project. He is now starting his group at the University of Washington. Together, we demonstrate all-optical ferroelectric switching in LiNbO₃ using mid-infrared pulses far below the bandgap. By harnessing the Raman force rather than resonant excitation, we achieve ultrafast, reversible polarization reversal with sub-picosecond dynamics and minimal energy consumption. This establishes a new route for light-driven control of material phases via nonresonant lattice forces.
Check it out: https://advanced.onlinelibrary.wiley.com/doi/full/10.1002/adma.202510524 

Emily and Hannah are joining our group!
We are fabricating our first devices. While Emily is finishing her Ph.D. with Masa Ishigamis, she is working with us on our first nanostructures. Hannah joins us as an undergraduate.  

Toward Attosecond Vortices in Semiconductors — now in Ultrafast Science! In collaboration with Shambhu Ghimire and Marcelo Ciappina, we demonstrate theoretically that semiconductor crystals such as ZnO can generate attosecond vortex pulses by combining high-harmonic generation with optical fields carrying orbital angular momentum. Using semiconductor Bloch equations and a thin-slab model, we show that structured attosecond light can emerge from solids, a milestone toward probing and controlling angular momentum dynamics at attosecond timescales.
Check it out: https://spj.science.org/doi/full/10.34133/ultrafastscience.0100 

Welcome, Saad, Denis, and Jacob!
Our group is growing, and we are excited to introduce our new members. Jacob and Denis are joining us as graduate students, and Saad will be joining as a postdoctoral researcher. Saad brings expertise and a deep theoretical background in attosecond science. We are excited to have all three on board and look forward to the exciting discoveries ahead together!

Optical control of electrons in a Floquet topological insulator — now on arXiv!In collaboration with Peter Hommelhoff’s group at FAU Erlangen, we demonstrate all-optical control of electrons in light-dressed graphene. Using circularly polarized femtosecond pulses and a phase-locked second harmonic, we generate a Floquet topological insulator and observe photocurrent circular dichroism, the all-optical anomalous Hall effect, and valley-polarized currents — establishing sub-cycle electron control in topological materials.
Check it out: https://arxiv.org/abs/2407.17917 

Welcome to the Team, Sepideh!
We are excited to welcome Sepideh as the first member of our group! Sepideh completed her PhD studying ultrafast carrier dynamics in 2D van der Waals materials on femtosecond-to-picosend timescales using THz spectroscopy techniques. In a few weeks, she is joining us to push the limits even further - exploring lightwave-driven phenomena in quantum materials at even shorter timescales. 

We are looking forward to the exciting research ahead!

Our group is online!
We are excited to launch our research group at UCF starting January 2025! Our journey will begin with ordering equipment and building state-of-the-art laser labs. We even asked DALL-E to imagine what our lab could look like—take a look at the result on the left! We're committed to bringing our vision to life and making our lab as colorful, vibrant, and innovative as possible.

Our Nature Review Physics Article on Petahertz Electronics is out!

Together with our colleagues Matthias Kling (Stanford) and Philip Keathley (MIT) we explore the cutting-edge advancements in attosecond science and how they have paved the way for petahertz electronics. 

Last year, attosecond science was recognized with the Nobel Prize, and today, we continue to push the boundaries by using tailored optical waveforms to control charge carriers at petahertz frequencies—a potential monumental leap beyond traditional electronics. Current control in solids and nanostructures far beyond gigahertz is a reality, opening up possibilities for direct sampling the electric field of light, similar to what is done in a conventional oscilloscope but at petahertz frequencies - the analog age of petahertz electronics. Today, we work on on-chip integration, next-generation transistors, ultrafast digital logic, and optical communications.

If you are interested in this research direction, check out the Research Section.

Check out our new article on Ultrafast High-Harmonic Spectroscopy in Nature Physics!

We explore the rapidly evolving field of high-harmonic generation (HHG) in condensed matter, a technique that originally emerged in atomic and molecular systems but has now grown into a platform for investigating electronic band structures, topological properties, and many-body correlations in solids.

In the article, we cover the following key topics:

📍 Microscopic Mechanism of High-Harmonic Generation

📍 Probing Atomically Thin Two-Dimensional Materials

📍 Probing Topological Properties

📍 Probing Strongly Correlated Materials

📍 Time-resolved high-harmonic Spectroscopy

The future of attosecond science sits at the exciting intersection of ultrafast and materials science, and we are excited to see where the next years take us! If you are interested in this research direction, check out the Research Section.