光致超声技术及其应用  

Laser-Generated Ultrasound Technology and Its Application

作　　者：王磊 李琳 赵永文 马丁昽 顾瑛[2] 王璞 Wang Lei;Li Lin;Zhao Yongwen;Ma Dinglong;Gu Ying;Wang Pu(Beijing Advanced Innovation Center for Biomedical Engineering,School of Biological Science and Medical Engineering,Beihang University,Beijing 100083,China;Department of Laser Medicine,the First Medical Center,PLA General Hospital,Beijing 100853,China)

机构地区：[1]北京航空航天大学生物与医学工程学院北京市生物医学工程高精尖创新中心,北京100083 [2]解放军总医院第一医学中心激光医学科,北京100853

出　　处：《中国激光》2023年第21期70-87,共18页Chinese Journal of Lasers

摘　　要：换能器作为超声系统的核心部分,起着重要的作用。传统的超声换能器是电驱动器件,利用材料的压电效应实现电-声转换,然而面对应用环境的苛刻要求,其有限的带宽限制了其在高标准要求环境中的应用。光致超声作为一种新型技术,利用激光代替电作为激励源获得超声,拥有传统压电技术无法具备的特性,如高频率和大带宽,这是成像和传感所需要的。同时,光致超声技术具有较为简单的换能器构架,避免了电子元件组装的复杂性,使得各种形状的超声换能器开发成为可能,比如凹形换能器和全向换能器。光致超声技术的这些优势使其有望获得更广泛的应用。对光致超声技术进行了介绍,主要包括光声机制、换能器性能表征和该技术在生物医学领域中的最新应用,并进一步讨论了光致超声技术未来可能的发展方向。Significance Biomedical ultrasound imaging has been widely used as an imaging technology based on ultrasound signals for viewing the internal structure of the body and finding the source of diseases.In recent decades,owing to the development of ultrasonic transducers,ultrasound imaging has made significant progress in obtaining important diagnostic information using rapid and noninvasive methods.Traditional transducers are excited by electricity and take advantage of the piezoelectric effect to achieve a transformation between electricity and ultrasound.However,considering the demanding requirements of application environments,the primary restriction is the limited bandwidth of traditional transducers.Laser-generated ultrasound,a novel technology based on photoacoustic effect,is excited by a laser instead of electricity.Ultrasound pulses are generated by the absorption of a short-pulse laser,thus leading to elastic thermal expansion caused by the transient temperature increase.In this process,the time-varying laser acts as the only excitation source.The upper limits of the energy and frequency of the ultrasound are restricted by the laser.Compared with piezoelectric transducers,the ultrasound generated by lasergenerated ultrasound transducers has the characteristics of high frequency and large bandwidth,which are necessary for sensing and imaging.With the breakthrough of laser-generated ultrasound transducers in the structural simplification and excitation of large-bandwidth ultrasound,laser-generated ultrasound technology has been gradually applied in various fields where traditional piezoelectric ultrasound methods cannot be applied,essentially providing a novel idea for high-precision and high-resolution biomedical applications.Progress The amplitude of ultrasound produced by laser-generated ultrasound technology is related to various characteristics,such as laser energy,transducer absorbance,thermal expansion coefficient,and shape.Moderately high-energy laser,highly absorbing nano-scale light absorbers,and ex

关 键 词：生物光学 光声效应 超声波 光致超声换能器 高频超声 

分 类 号：O426.3[理学—声学]