Optically excited nanoscale ultrasonic transducers
Optically excited nanoscale ultrasonic transducers
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DOI：
10.1121/1.4904487
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发表时间：
2015-01-01
影响因子：
2.4
通讯作者：
Clark, Matt
中科院分区：
文献类型：
--
作者：
Smith, Richard J.;Cota, Fernando Perez;Clark, Matt
为了在更高的超声波频率下工作，例如，为了提高分辨率，有必要制造更小和更高频率的换能器。本文介绍了一种能够以非常小的尺寸制作并在GHz频率下工作的超声波换能器。传感器被激活并使用脉冲激光进行光学读取，仪器和传感器之间没有物理接触。这消除了传统压电结构的一些实际障碍（如布线），并允许器件立即放置在样品上或样品内，减少了衰减的显著影响，衰减在1 GHz以上的频率上非常强烈。本文提出的换能器利用同时的光学和机械共振将光输入耦合到超声波中，反之亦然。本文讨论了在适度尺度（几微米）下器件的机械和光学设计，并探讨了传感器向亚微米尺度的缩放。结果表明，换能器的响应如何随其局部环境而变化，以及当换能器被打印的蛋白质样品加载时，谐振频率如何变化。(C) 2015年美国声学学会。
In order to work at higher ultrasonic frequencies, for instance, to increase the resolution, it is necessary to fabricate smaller and higher frequency transducers. This paper presents an ultrasonic transducer capable of being made at a very small size and operated at GHz frequencies. The transducers are activated and read optically using pulsed lasers and without physical contact between the instrumentation and the transducer. This removes some of the practical impediments of traditional piezoelectric architectures (such as wiring) and allows the devices to be placed immediately on or within samples, reducing the significant effect of attenuation which is very strong at frequencies above 1 GHz. The transducers presented in this paper exploit simultaneous optical and mechanical resonances to couple the optical input into ultrasonic waves and vice versa. This paper discusses the mechanical and optical design of the devices at a modest scale (a few mu m) and explores the scaling of the transducers toward the sub-micron scale. Results are presented that show how the transducers response changes depending on its local environment and how the resonant frequency shifts when the transducer is loaded by a printed protein sample. (C) 2015 Acoustical Society of America.