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As we transition into a new era of the information age—fueled by intelligent algorithms, advanced classical and quantum sensors, and ever-expanding computing resources alongside vast amounts of data—we also face significant technological challenges and scientific questions in chip-scale optoelectronics. For example, can we further push the bandwidth limits of optical interconnects? How can quantum signals be efficiently transduced from the visible to the telecom bands to enable scalable quantum interconnects? How can we generate, and process optical information in an ultrafast and energy-efficient manner? Addressing these challenges demands the strategic selection and engineering of scalable, multi-functional optoelectronic materials, along with innovative device physics and architectures.

Despite its long history in bulk form, lithium niobate (LN) in its thin-film form has recently emerged as one of the most promising material platforms for integrated photonics. This is due to its strong electro-optic (Pockels) effect, large quadratic ( optical nonlinearity, the availability for ferroelectric domain engineering and quasi-phase-matching, and the broad optical transparency window. In this talk, I will first review the rich optoelectronic properties of LN, and illustrate how LN nanophotonics unlocks new regimes in ultrafast and ultra-wide bandwidth nonlinear photonics. I will then present our recent experimental advancements in engineering the thin-film lithium niobate (TFLN) material platform to enable ultra-wide bandwidth, ultrafast, and ultra-low energy integrated photonic devices. These include the realization of 100 dB/cm on-chip optical parametric amplification, widely wavelength-tunable (1.5–3 µm) optical parametric oscillator, electrically reconfigurable octave-bandwidth optical amplifier from visible to telecom bands, femtosecond and femtojoule on-chip all-optical switching, and integrated ultrafast mode-locked lasers on TFLN.

Qiushi Guo is an Assistant Professor at the Advanced Science Research Center (ASRC) at the City University of New York (CUNY). Before joining ASRC and the CUNY Graduate Center in 2023, he was a postdoctoral research associate at the California Institute of Technology. He earned his Ph.D. in Electrical Engineering from Yale University in December 2019 and was awarded the 2020 Henry Prentiss Becton Prize for his outstanding research achievements on mid-infrared optoelectronics in 2-D van der Waals materials and heterostructures. Dr. Guo is a recipient of the Office of Naval Research Young Investigator Award, the Army Research Office Early Career Award, and the NSF CAREER Award, and was named one of the 2022 Rising Stars of Light. His research interests span integrated nonlinear and quantum photonics, mid-infrared optoelectronics, and low-dimensional quantum materials. He has authored over 50 peer-reviewed publications in leading scientific journals, with more than 6,000 citations. He is also a co-founder of AmpVisions LLC, which commercializes the Silicon Thermal Transistor technology for thermal imaging.