Jiang Xiaoping, Shen Mengqi, Lun Daniel Pak-Kong, Chen Wen, Somekh Michael G
Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Nanophotonics Research Centre, Shenzhen Key Laboratory of Micro-Scale Optical Information Technology, Shenzhen University, Shenzhen 518060, Guangdong, China.
Photoacoustics. 2023 Feb 24;30:100466. doi: 10.1016/j.pacs.2023.100466. eCollection 2023 Apr.
In photoacoustic and ultrasound imaging, optical transducers offer a unique potential to provide higher responsivity, wider bandwidths, and greatly reduced electrical and acoustic impedance mismatch when compared with piezoelectric transducers. In this paper, we propose a total-internal-reflection-based Fabry-Pérot resonator composed of a 12-nm-thick gold layer and a dielectric resonant cavity. The resonator uses the same Kretschmann configuration as surface plasmon resonators (SPR). The resonators were analyzed both theoretically and experimentally. The experimental results were compared with those for an SPR for benchmarking. The 1.9-μm-thick-PMMA- and 3.4-μm-thick-PDMS-based resonators demonstrated responsivities of 3.6- and 30-fold improvements compared with the SPR, respectively. The measured bandwidths for the PMMA, PDMS devices are 110 MHz and 75 MHz, respectively. Single-shot sensitivity of 160 Pa is obtained for the PDMS device. The results indicate that, with the proposed resonator in imaging applications, sensitivity and the signal-to-noise ratio can be improved significantly without compromising the bandwidth.
在光声和超声成像中，与压电换能器相比，光学换能器具有独特的潜力，能够提供更高的响应度、更宽的带宽，并大大降低电和声阻抗失配。在本文中，我们提出了一种基于全内反射的法布里-珀罗谐振器，它由一个12纳米厚的金层和一个介质谐振腔组成。该谐振器采用与表面等离子体谐振器（SPR）相同的克雷奇曼配置。对谐振器进行了理论和实验分析。将实验结果与用于基准测试的SPR的结果进行了比较。基于1.9微米厚的聚甲基丙烯酸甲酯（PMMA）和3.4微米厚的聚二甲基硅氧烷（PDMS）的谐振器分别显示出与SPR相比响应度提高了3.6倍和30倍。PMMA、PDMS器件的测量带宽分别为110兆赫兹和75兆赫兹。PDMS器件的单次灵敏度为160帕斯卡。结果表明，在所提出的谐振器用于成像应用时，在不影响带宽的情况下，可以显著提高灵敏度和信噪比。
