New Microlasers: Structuring and Twisting Laser Radiations at a Microscale

非技术描述：激光是光学和光子学领域中超越其他光子元件的关键驱动因素。自发现以来，激光技术已经对各种各样的应用产生了强大的影响，特别是在当今支持快速增长的云计算和通信的信息技术中。然而，由于信息信道可用的电磁频谱有限，目前基于波分复用的信息基础设施已接近瓶颈。利用光的轨道角动量作为一种新的信息传输自由度的新技术将进一步推动现代信息系统的发展。在本项目中，利用最先进的集成光子学技术，将研究一种破坏性微激光技术，以直接编码微激光辐射的轨道角动量信息。创造新形式的微尺度激光产生和执行复杂的光学响应的能力为推进基础激光科学和下一代用于计算和通信的光子设备和系统提供了前所未有的前景。该研究与现有的教育活动紧密结合，通过让本科生和研究生接触到有源纳米光子器件的令人兴奋的发展，以解决光通信和信息处理中的重要社会问题，从而激发他们追求工程事业。此外，政府亦会提供教育外展活动，以促进小至十二年级学生的兴趣和参与，并扩大弱势群体的参与。技术描述：基于结构光束角动量的变革性技术可以在独特的多维空间中实现全新的高速安全光通信系统。然而，将这种独特的基于角动量的信息空间移动到通信系统中的关键问题在于激光源。本项目将开发新型集成纳米光子激光源，实现光子轨道角动量信息的存储和处理。本项目的目的是，从对称的角度，确定光场拓扑和光子结构对称性之间的相互作用，以设计微激光作用中规定的光-物质相互作用。通过设计的光-物质相互作用，可以有效地调整光子系统的对称性，重塑光子态的密度；从而导致在微/纳米尺度上对光发射的按需元控制。因此，在光子集成芯片上可以充分探索光的丰富性质，包括自旋（即圆极化）、手性、角动量和自旋-轨道耦合，提供具有多种不同和可重构轨道角动量的新形式的微/纳米激光。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 description: Laser is the key driver in the field of optics and photonics over other photonic components. Since its discovery, laser technology has demonstrated strong impacts on a broad variety of applications, especially in today's information technology supporting fast growing cloud computing and communication. However, with the limited electromagnetic spectrum available for information channels, the current information infrastructure based on the wavelength division multiplexing is approaching its bottleneck. Novel technologies leveraging the orbital angular momentum of light as a new degree of freedom for carrying information become promising to further advance modern information systems. In this project, utilizing the state-of-the-art integrated photonics technology, a disruptive microlaser technology will be investigated to directly encode information on the orbital angular momentum of the microlaser radiations. The capability of creating new forms of microscale lasing generation and executing complex optical responses offers an unprecedented perspective to advance both fundamental laser science and the next generation of photonic devices and systems for computing and communication. This research is closely integrated with the existing educational activities, stimulating undergraduate and graduate students to pursue engineering career by exposing them to the exciting development of active nanophotonic devices solving important societal problems in optical communication and information processing. The educational outreach activities will also be provided to promote the interests and participations of K-12 students and broaden the participations from underrepresented groups. Technical description: Transformative technologies based on the angular momentum in structured light beams can enable the implementation of entirely new high-speed secure optical communication systems in a unique multidimensional space. A critical problem in moving this unique angular momentum-based information space into the communication system, however, lies in the laser sources. In this project, development of new integrated nanophotonic laser sources will be carried out to enable storing and processing information in the orbital angular momentum of photons. The objective of this project is, from a symmetry point of view, to identify the interplay between the topology of optical fields and the symmetry of photonic structures to design prescribed light-matter interactions in microlaser actions. Through the designed light-matter interaction, the symmetry of the photonic system can be effectively tailored to reshape the density of states of photons; thereby leading to on-demand meta-control of light emission at the micro/nano-scale. Therefore, the rich nature of light can be fully explored on a photonic integrated chip including spin (i.e. circular polarization), chirality, angular momentum, and spin-orbit coupling, delivering new forms of micro/nano-lasing carrying a large variety of different and reconfigurable orbital angular momenta.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.