NER: Photoacoustic Characterization of Nanoelectromechanical Systems

在这个建议中，我们将开发高分辨率的光声技术，用于产生和检测纳米级系统中的声振动，并证明该系统在双钳位NEMS梁resonators.The当前NER建议的特性的可行性，旨在克服这些分辨率的光声显微镜的问题，并证明其适用于纳米尺度的设备：NEMS。为了实现这一目标，我们将开发一种光学近场光声显微镜系统，使我们能够在NEMS设备中产生和检测声学和热振动。该系统将有一个调制的CW激光器（高达5 GHz）的激励和CW探测激光器将用于监测局部位移和温度，分别。采用高折射率固体浸没透镜（SIL）克服空气中的衍射极限，将获得高的空间分辨率。基于SIL的技术非常适合NEMS设备中声波的产生和检测，因为它允许将激光光斑尺寸减小到空气中的衍射极限以下，同时保持高灵敏度干涉检测所需的光通量。拟议的研究工作旨在评估这种实验技术，这将作为一种使能技术，并帮助回答有关通过这些设备的能量流的基本问题。这一NER的努力将允许对NEMS的高分辨率光声显微镜进行初步可行性研究，并为未来的近-场光学探针，用于纳米结构中声学声子的产生和检测。研究生的支持也包括在这方面的努力。学生将有一个真正的跨学科的教育经验，并接受近场光学，声学和纳米力学领域的培训。该NER特别涉及以下主题：

In this proposal, we will develop high-resolution photoacoustic techniques for generating and detecting acoustic vibrations in nanoscale systems and demonstrate the feasibility of this system in the characterization of doubly clamped NEMS beam resonators.The current NER proposal seeks to overcome these resolution problems in photoacoustic microscopy and demonstrate its applicability to nanometer scale devices: NEMS. To accomplish this, we will develop an optical near-field photoacoustic microscopy system that will allow us to generate and detect acoustic and thermal vibrations in NEMS devices. This system will have a modulated CW laser (up to 5 GHz) for excitation and a CW probe laser will be used to monitor the local displacement and temperature, respectively. High spatial resolution will be obtained by incorporating a high refractive index solid immersion lens (SIL) to overcome the diffraction limit in air. The SIL based technique is well suited for the generation and detection of acoustic waves in NEMS devices because it allows for reduction of laser spot size below the diffraction limit in air while maintaining the optical throughput necessary for high sensitivityinterferometric detection. The proposed research effort is aimed at evaluating this experimental technique, which will act as an enabling technology and help answer fundamental questions regarding the energy flow through these devices.This NER effort will allow for an initial feasibility study on high-resolution photoacoustic microscopy of NEMS and provide the foundation for future development of near-field optical probes for the generation and detection of acoustic phonons in nanoscale structures. Graduate student support is also included in this effort. The students will have a truly interdisciplinary educational experience and receive training in the areas of near-field optics, acoustics, and nanoscale mechanics. This NER specifically addresses the following themes: