Mid-infrared reconfigurable pulse generators

中红外可重构脉冲发生器

• 批准号: 2221715
• 负责人: Federico Capasso
• 金额: $ 36万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2221715&HistoricalAwards=false
• 关键词: Mid; infrared; reconfigurable; pulse; generators

Lasers are indispensable tools that benefit our society on many different avenues. Laser utility comes from it being able to emit light of precisely defined wavelength –– and an extremely stable intensity, making it especially suitable for measurements requiring utmost precision and in connecting the world by using laser light as a carrier of digital information in undersea fiber optic cables. More applications, however, would benefit from a new kind of laser, that emits simultaneously not one, but many wavelengths of light. The goal of the project is to realize precisely this kind of laser. The output intensity of such a laser is no longer constant, but is a train of short light pulses, all spaced by equal time intervals. These pulses will attain extremely high optical intensities –– much higher than a single- wavelength laser could provide. Such intense pulses would be especially useful to optical spectroscopists –– scientists who strive to deepen our understanding of matter by studying how it absorbs and emits laser light. Short intense pulses of light can serve as a precise clockwork mechanism to time the response of the material to laser radiation, which can be used for real time monitoring of chemical reactions and for the studies of the nonlinear optical response of atomic vapors, gas molecules and semiconductor crystals, directly impacting disciplines from solid-state physics to biology, with potential applications in the medical research. The primary goal of the project is the demonstration of a new device architecture ¬¬–– a mid-infrared ring quantum cascade laser with an integrated active directional coupler, driven by a coherent external laser source. By acting on the drive laser intensity and its detuning from the ring laser frequency it will be possible to reconfigure the state of the ring laser on-demand, ranging from bright and dark cavity solitons, representing respectively ultrashort pulses of light that propagate without broadening in the laser medium and “dark pulses” in a background of continuous laser light, respectively, to more complex waveforms known as Turing rolls and phase solitons –– all in one, all-electrically controlled device. Starting with the design and modeling of laser resonators using commercial electromagnetic mode solvers and an in-house custom laser simulator the researchers will proceed with nanoscale semiconductor processing according to the developed designs. Characterization of fabricated devices will be based on basic emission spectroscopy of laser output as well as complex temporal waveform reconstruction using already existing optical interferometers and the setups constructed within the timespan of the project. The project will encompass broader theoretical studies in mathematical physics centered around pattern formation in nonlinear active resonators and will deepen the understanding of the similarities and the differences of the physics of frequency comb formation in passive and active optical resonators. Achieving ultrashort pulse generation in the mid-infrared from compact chip-scale devices may be transformative for fundamental science allowing to probe the temporal dynamics of ultrafast material processes occurring at mid-infrared frequencies — from phonons to polaritons to interactions of complex organic molecules.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.

激光是在许多不同方面造福我们社会的不可或缺的工具。激光的实用性在于它能够发射精确定义的波长和极其稳定的强度，这使得它特别适合需要最高精度的测量以及通过连接世界。然而，更多的应用将受益于一种新型激光器，它可以同时发射多种波长的光，而不是一种光。该项目的目标是实现精确的发射。这这种激光器的输出强度不再是恒定的，而是一系列短光脉冲，所有脉冲都以相等的时间间隔间隔，这些脉冲将获得极高的光强度——远高于单波长激光器。这种强脉冲对于光学光谱学家特别有用，科学家们致力于通过研究物质如何吸收和发射激光来加深我们对物质的理解。短强光脉冲可以作为精确的发条机制来计时响应。的材料到激光辐射，可用于实时监测化学反应以及研究原子蒸气、气体分子和半导体晶体的非线性光学响应，直接影响从固态物理学到生物学的学科，在医学领域具有潜在的应用该项目的主要目标是展示一种新的设备架构——带有集成有源定向耦合器的中红外环量子级联激光器，由相干外部激光源驱动，作用于驱动激光强度。及其失谐根据环形激光器频率，可以按需重新配置环形激光器的状态，范围从亮腔孤子到暗腔孤子，代表在激光介质中传播而不会展宽的超短光脉冲和背景中的“暗脉冲”分别从连续激光到被称为图灵辊和相位孤子的更复杂的波形——全部在一个全电控设备中，从使用商用电磁模式的激光谐振器的设计和建模开始。研究人员将根据已开发的设计，基于激光输出的基本发射光谱以及使用现有光学干涉仪和复杂的时间波形重建，继续进行纳米级半导体加工。该项目将涵盖以非线性有源谐振器中的图案形成为中心的更广泛的数学物理理论研究，并将加深对无源和有源频率梳形成物理学的相似性和差异的理解。从紧凑的芯片级设备中实现中红外超短脉冲的产生可能会对基础科学产生革命性的影响，从而能够探测中红外频率下发生的超快材料过程的时间动力学——从声子到极化子再到复杂有机物的相互作用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。