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

解开自然界中最快时间尺度秘密的关键在于飞秒锁模激光器（MLL）-强大的设备，以惊人的千万亿分之一秒发射超短相干光脉冲。在芯片级实现飞秒MLL和超快光子系统，集成光子电路可以解锁许多以前传统桌面设置无法实现的应用。这些应用，如便携式原子钟和先进的生物成像工具，有可能在生物医学科学、国防和信息处理领域带来变革性的影响。然而，现有的芯片级集成MLLs缺乏峰值强度和可控程度，这阻碍了集成超快光子系统的实现。该项目通过利用新型激光增益介质和新兴的薄膜锂酸盐集成光子材料平台来解决这些挑战，目标是实现高功率，可重构的飞秒MLL和新型集成超快光子系统。此外，PI和他的团队将建立几个新的推广活动和培训计划，为国家的半导体和光电劳动力准备不同背景的学生。这些措施包括：（1）关于半导体器件和集成光子学的新模块和远程访问教学实验室;（2）一系列讲习班，使处境不利的地方高中的科学教师能够了解半导体和光子学的最新进展，并就有效的物理教学战略进行合作;（3）“科学之夜”活动，以促进高中生的科学探索和培养他们的兴趣和（4）在PI的实验室在纽约市立大学的先进科学研究中心的暑期实习，该中心为来自弱势群体的高中生提供最先进的设施以及半导体和集成光子学领域的前沿研究项目。技术描述：在这个CAREER计划中，主要研究者和他的团队的目标是（1）在薄膜锂酸盐（TFLN）上开发芯片级全集成锁模激光器（MLL），该激光器可以在微波重复率下产生飞秒脉冲，片上峰值功率超过10瓦，以及（2）实现完全集成的超快光子系统，例如集成超连续谱激光器和自通过将高峰值功率MLL与其他基于TFLN的非线性光子器件无缝集成，实现了参考频率梳。这些创新的核心在于研究和利用一种新型的激光增益介质，以及集成光子学中光-物质相互作用的未探索机制。在这种新的制度下，片上激光增益与TFLN纳米光子学的能量效率和瞬时二次光学非线性相互作用，有望形成高效，稳定和可重构的飞秒光脉冲。高峰功率集成MLL的成功开发及其与其他基于TFLN的非线性光子器件的无缝集成可以实现一套尚未在集成光子学中实现的系统级功能，这将在下一代光学成像，计量，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准。

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 of diverse backgrounds 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 disadvantaged 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 from underrepresented groups 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.