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

本研究介绍了一种制造中红外光谱区发射电磁波的量子级联半导体激光光源的新方法。高效、高功率中红外激光源被广泛应用，包括天体物理光谱测量、遥感、气相光谱和红外对抗。在这项工作中，我们的团队将研究一种开发具有优异光束质量的高功率激光器的新策略，量子级联（QC）垂直外腔表面发射激光器（VECSEL）。我们团队的一部分人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，我们将重新设想较短的中红外波长的概念。我们提出了一套针对包括中红外在内的各种光谱子区域的方法，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，支持招募和留住代表性不足的少数族裔。研究目标是开发中红外光谱范围的量子级联（QC）垂直外腔表面发射激光器（VECSELs）。这被提议作为(a)具有可扩展输出功率（高达数十瓦）的高亮度中红外源在圆形衍射限制光束中的路径，以及(b)多功能激光器的平台，该平台具有局部设计超表面的幅度，相位和偏振响应的能力。我们提出了一套独特的方法，为包括中红外的各种光谱子区域量身定制。所建议的工作中的智力价值体现在多个层面上。主要的创新是开发了用于中红外量子级联激光器的VECSELs的新方案，特别是基于表面发射光栅的MWIR和LWIR。更广泛的影响涉及几个层面，包括本科生和研究生的研究经验，成果的传播，技术进步，向未被充分代表的少数民族的推广，以及产业互动。向未被充分代表的少数群体（URM）的外展活动将特别通过PI进行。为一门专为招录和留住大学工程学新生而设计的课程，开展研究项目。这个目标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/接触行业。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.