CAREER: Integrated Lithium Niobate Femtosecond Mode-Locked Lasers and Ultrafast Photonic Systems

Research Foundation Cuny - Advanced Science Research Center, New York NY

Investigators

Abstract

The key to unlocking the secrets of the fastest timescales in nature lies with femtosecond mode-locked lasers (MLLs) - powerful devices that emit ultrashort, coherent optical pulses at an astonishing quadrillionth of a second. Realizing femtosecond MLLs and ultrafast photonic systems on chip-scale, integrated photonic circuits can unlock a multitude of applications previously beyond the reach of conventional tabletop setups. These applications, such as portable atomic clocks and advanced biological imaging tools, have the potential to bring transformative impacts across biomedical science, national defense, and information processing. However, existing chip-scale integrated MLLs lack the peak intensities and degrees of controllability, which impede the realization of integrated ultrafast photonic systems. This project addresses these challenges by leveraging novel laser gain media and the emerging thin-film lithium niobate integrated photonic material platform, with the goal of realizing high-power, reconfigurable femtosecond MLL and novel integrated ultrafast photonic systems. In addition, the PI and his team will establish several new outreach activities and training programs that prepare students for the nation’s semiconductor and optoelectronic workforce. These include (1) new modules and remotely accessible teaching labs on semiconductor devices and integrated photonics; (2) a workshop series empowering science teachers at local high schools with cutting-edge advances in semiconductor and photonics and collaborating on effective teaching strategies for physics; (3) “Science Night” events to promote scientific exploration among high school students and nurture their interest and (4) Summer Internship at the PI’s lab at CUNY’s Advanced Science Research Center, which exposes high school students to state-of-the-art facilities and cutting-edge research projects in semiconductor and integrated photonics. Technical description: In this CAREER program, the principle investigator and his team aims to (1) develop chip-scale, fully-integrated mode-locked lasers (MLL) on thin-film lithium niobate (TFLN) that can generate femtosecond pulses at microwave repetition rate with a high on-chip peak power exceeding 10 watts, and to (2) realize fully integrated ultrafast photonic systems such as integrated supercontinuum lasers and self-referenced frequency combs by seamlessly integrating high-peak power MLL with other TFLN-based nonlinear photonic devices. At the core of these innovations lies the investigation and utilization of a novel laser gain medium, and an unexplored regime of light-matter interaction in integrated photonics. Within this new regime, the on-chip laser gain interplays with the energy-efficient, and instantaneous quadratic optical nonlinearity of TFLN nanophotonics, promising efficient, stable, and reconfigurable femtosecond light pulse formation. The successful development of high peak power integrated MLLs and their seamless integration with other TFLN-based nonlinear photonic devices can enable a suite of system-level functionalities that have not yet been realized in integrated photonics, which will play major roles in next-generation optical imaging, metrology, and photonic information processing. 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.