GOALI: Mid-infrared quantum-cascade metasurfaces for external cavity lasers

本研究介绍了一种新的方法，使量子级联半导体激光光源，发射电磁波在中红外光谱区。高效、高功率的中红外激光光源在天体物理光谱测量、遥感、气相光谱和红外对抗等领域有着广泛的应用。在这项拟议的工作中，我们的团队将研究一种新的策略，用于开发具有优异光束质量的高功率激光器，即量子级联（QC）垂直外腔面发射激光器（VECSEL）。我们团队的一部分最近在太赫兹光谱区域（波长大于60微米）开发了这项技术，在这个项目中，我们将重新设想更短的中红外波长的概念。我们提出了一套适合于各种光谱子区域的方法，包括中红外，包括甚长波红外（VLWIR）光谱区域（16-28微米波长），长波红外（LWIR）（8-13微米波长），和中波红外（MWIR）（4-5微米波长）。这项工作是加州大学洛杉矶分校的PI和诺斯罗普·格鲁曼航空航天系统公司的工业合作伙伴之间的GOALI大学-工业合作。作为该项目的一部分，该研究将培训研究生和本科生，并将通过参与有针对性的研究项目课程来支持招聘和保留代表性不足的少数民族工程师。技术支持该研究的目标是开发中红外光谱范围的量子级联（QC）垂直外腔面发射激光器（VECSEL）。这被提议作为（a）在圆形衍射限制光束中具有可缩放输出功率（高达数十瓦）的高亮度中IR源的路径，以及（B）与局部设计超表面的振幅、相位和偏振响应的能力相关联的多功能激光器的平台。我们提出了一套独特的方法，适合于各种光谱子区域，包括中红外。在所提出的工作中的智力价值是目前在多个层面上。主要的创新是开发用于实现中红外量子级联激光器的VECSEL的新方案，特别是在基于表面发射光栅的MWIR和LWIR中。更广泛的影响在几个层面上得到解决，包括本科生和研究生的研究经验，传播成果，技术进步，推广到代表性不足的少数民族，和工业互动。对代表性不足的少数民族（URM）的宣传将具体通过PI进行？的研究项目的发展，为URM工程新生的招聘和保留设计的课程。该GOALI计划将导致大学和工业合作伙伴之间的互动，潜在的技术转让和学生培训/行业内的曝光。该奖项反映了NSF的法定使命，并已被认为是值得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的支持。

Non-technical descriptionThis research introduces a new approach for making quantum-cascade semiconductor laser light sources that that emit electromagnetic waves in the mid-infrared spectral region. Efficient and high-power mid-infrared laser sources are desired for a wide range of applications, including astrophysical spectral measurements, remote sensing, gas-phase spectroscopy, and infrared countermeasures. In this proposed work, our team will investigate a new strategy for developing high-power lasers with excellent beam quality, the quantum-cascade (QC) vertical-external-cavity surface-emitting-laser (VECSEL). Part of our team has recently developed this technology in the terahertz spectral region (wavelengths greater than 60 microns), in this project we will re-envision the concept for the shorter mid-infrared wavelengths. We propose a suite of approaches tailored for the various spectral sub-regions that comprise the mid-infrared, including the very-long-wave-infrared (VLWIR) spectral region (16-28 micron wavelength), the long-wave infrared (LWIR) (8-13 micron wavelength), and the mid-wave infrared (MWIR) (4-5 micron wavelength). This work is a GOALI university-industry collaboration between the PI at UCLA and an industrial partner at Northrop Grumman Aerospace Systems. As a part of the project, the research will train graduate and undergraduate students, and will support recruitment and retention of underrepresented minorities to engineering through participation in a targeted research project course.Technical descriptionThe research goal is to develop quantum-cascade (QC) vertical-external-cavity surface-emitting-lasers (VECSELs) in the mid-infrared spectral range. This is proposed as path for (a) high brightness mid-IR sources with scalable output power (up to tens of watts) in a circular diffraction-limited beam, and (b) a platform for multifunctional lasers associated with the ability to locally engineer the amplitude, phase, and polarization response of the metasurface. We propose a set of distinct approaches tailored for the various spectral sub-regions that comprise the mid-IR. The intellectual merit in the proposed work is present on multiple levels. The primary innovation is the development of novel schemes for implementing VECSELs for mid-infrared quantum-cascade lasers, in particular in the MWIR and LWIR based upon surface-emitting gratings. The broader impacts are addressed at several levels including undergraduate and graduate research experiences, dissemination of results, technology advancement, outreach to underrepresented minorities, and industrial interaction. Outreach to underrepresented minorities (URM) will specifically occur through the PI?s development of research projects for a course designed for the recruitment and retention of URM engineering freshman. This GOALI program will result in interaction between the university and industrial partner, potentially for technology transfer and student training/exposure within industry.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.