EAGER: Coherent Terahertz Generation in Silica Micro-Resonators

我们计划通过首次利用THz参数振荡器中的回音廊增强来设计、制造和实验演示一种新型的THz发射器。这些微米级的回声廊模谐振器提供了极高的谐振品质因数，不仅为光泵提供了前所未有的腔增强因子，而且为产生的太赫兹波提供了前所未有的腔增强因子。我们的初步计算表明，这种增强可以将太赫兹源转换为相干(10 GHz带宽)、线性极化、频率可调的太赫兹发射，与现有技术相比，功率效率高出100倍。智力优势：拟议的工作为从根本上提高现有太赫兹源的性能提供了一个全新的视角，即利用耳语厨房模谐振器的潜在用途。回声走廊的增强使我们在过去第一次实验演示了(1)微谐振器中的三次谐波，(2)微谐振器中的布里渊散射，以及(3)辐射压力下的机械振动。利用这一经验，我们将探索在二氧化硅微谐振器中使用类似的回音廊增强来提高光到THz的转换效率。理论研究对回音廊增强型太赫兹参量振荡器的基本转换效率极限有了深入的了解。它们还为太赫兹耳语画廊增强的物理要求提供了有价值的见解。此外，实验工作为开发合适的二氧化硅微谐振器太赫兹发射器提供了一个直观的限制和解决方案。广泛影响：拟议的研究成果将使高性能的医学成像、生物传感、安全筛查和化学识别系统目前受到现有太赫兹源的低输出功率的限制。教育与研究活动的整合：将建立一个特殊的培训计划，以吸收从事这种跨学科研究的研究生，将招募本科生和暑期实习生参加研究活动，将特别优先招聘有才华的女性和本科生候选人以及代表性不足的群体成员。我们的博士生已经在教授人口比例偏低的学生；我们打算通过一系列实验将太赫兹研究整合到学校活动中，以吸引这些学生在这个三年项目结束时申请大学。将开发新的研究生课程和跨学科研讨会，并将在本科课程中加入新的教学模块，我们将通过易于浏览的网页、每年两次的研讨会和开放参观以及为高中生安排的科学演示向公众传播我们研究成果的最新信息和教育教程。

Proposal summaryWe propose to design, fabricate, and experimentally demonstrate a new type of THz emitter by exploiting, for the first time, whispering-gallery enhancement in a THz parametric oscillator. The extremely high resonance quality factors offered by these micron-scale whispering-gallery mode resonators offer unprecedented cavity enhancement factors not only for the optical pump, but also for the generated THz wave. Our preliminary calculations show that such enhancement can transform THz sources to allow a coherent (10 GHz bandwidth), linearly polarized, frequency tunable THz emission with 100 times higher power efficiencies compared to the state-of-the art.Intellectual merit:The proposed work presents an entirely new perspective on the potential use of whispering-galley mode resonators to radically improve the performance of existing terahertz sources. Whispering-gallery enhancement allowed us in the past to be the first to experimentally demonstrate (1) Third-harmonic in a micro-resonator, (2) Brillouin scattering in a micro-resonator, and (3) mechanical vibration by radiation pressure. Using this experience we will explore the use of similar whispering-gallery enhancement to benefit optical-to-THz conversion efficiency in a silica micro-resonator. Theoretical investigations provide a deep understanding of fundamental conversion efficiency limitations of whispering-gallery enhanced THz parametric oscillators. They also offer a valuable insight to physical requirements for THz whispering gallery enhancement. Additionally, the experimental efforts provide an intuitive insight to practical constraints and solutions to develop proper silica micro-resonator THz emitters.Broader Impact:The outcome of the proposed research will enable high-performance medical imaging, biological sensing, security screening and chemical identification systems which are currently limited by the low output power of the existing terahertz sources.Integration of education with research activities:A special training program will be constructed to assimilate graduate students working on this type of interdisciplinary research, undergraduate students and summer interns will be recruited for the research activities, special priority will be given to recruitment of talented women undergraduate and graduate candidates and the members of underrepresented groups. Our PhD students is already teaching pupils from underrepresented population; we intend to integrate The THz research into this school activity via a series of experiment in order to attract this students to apply to university at the end of this 3 year project when the children will be 18. New graduate courses and interdisciplinary seminars will be developed and new teaching modules will be included in undergraduate courses, an update on our research results and educational tutorials will be disseminated to the public via easy-to-navigate web pages, bi-annual seminars and open house visits and scientific demos will be arranged for high school students