NSF-SNSF: Multilayer Oxide-clad LIthium Niobate On-chip (MOLINO) devices for mid-IR frequency comb generation

Stanford University, Stanford CA

Investigators

Abstract

This project aims to develop an integrated photonic platform called MOLINO (Multilayer Oxide-clad LIthium Niobate On-chip) for efficient and compact generation of mid-infrared frequency combs. Frequency combs are precise tools for measuring different colors of light and have revolutionized metrology, spectroscopy, and sensing. However, current mid-infrared frequency comb sources are limited by high cost, low efficiency, and large size. By leveraging recent advances in lithium niobate nanophotonics and ultrafast laser technology, this project will create chip-scale mid-infrared frequency comb sources that require orders-of-magnitude less power than current systems while having much broader bandwidth and lower cost. If successful, this project will dramatically expand accessibility to mid-infrared frequency combs, accelerating scientific discovery and enabling new technologies to monitor greenhouse gasses, analyze chemicals, and sense biomolecules for health monitoring. This project will also train graduate students in cutting-edge skills in ultrafast optics and nanophotonics, supporting a diverse high-tech workforce. The collaboration between US and Swiss research teams will strengthen international scientific ties and leverage complementary expertise to maximize the project's impact. Technical description: The goal of this project is to develop the MOLINO platform, a chip-scale platform for generating broadband mid-infrared frequency combs pumped by ultrafast near-infrared lasers. This will be achieved through a collaboration between teams at Stanford University and University of Neuchâtel with three synergistic thrusts: (1) developing advanced GHz-repetition-rate, ultrashort-pulse-duration lasers in the 1-2 µm band based on Yb and Tm gain media; (2) creating multilayer-clad, dispersion-engineered lithium niobate nanophotonic waveguides and resonators with low loss, high nonlinearity, and low sensitivity to fabrication imperfections; and (3) demonstrating broadband, coherent mid-infrared light generation in MOLINO devices through nonlinear optical effects such as supercontinuum generation, difference frequency generation, and synchronously-pumped optical parametric oscillation. The teams will leverage their world-leading capabilities in ultrafast solid-state laser development, ion-beam-sputtered optical coatings, thin-film lithium niobate nanofabrication, and characterization of nonlinear photonic devices. The Swiss team will focus on laser development and coating fabrication, while the US team will lead MOLINO device design and fabrication, and the teams will work together to demonstrate and characterize the nonlinear dynamics of the MOLINO devices. If successful, this project could extend the bandwidth, efficiency, and repeatability of chip-based mid-infrared frequency comb sources by orders of magnitude beyond the state-of-the-art. This collaborative U.S.-Swiss project is supported by the U.S. National Science Foundation (NSF) and the Swiss National Science Foundation (SNSF), where NSF funds the U.S. investigator and SNSF funds the partners in Switzerland. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.