基于双片锯齿电极的宽带声光偏转器  

Wideband Acousto-Optic Deflector Based on Double Sawtooth Electrodes

作　　者：汪昱聪 王梓 梁力 冯奇斌[1] 吕国强[2] Wang Yucong;Wang Zi;Liang Li;Feng Qibin;LüGuoqiang(Special Display and Imaging Technology Innovation Center of Anhui Province,National Engineering Laboratory of Special Display Technology,Academy of Photoelectric Technology,Hefei University of Technology,Hefei 230009,Anhui,China;School of Instrument Science and Opto-Electronics Engineering,Hefei University of Technology,Hefei 230009,Anhui,China)

机构地区：[1]合肥工业大学特种显示与成像技术安徽省技术创新中心,特种显示技术国家工程实验室,光电技术研究院,安徽合肥230009 [2]合肥工业大学仪器科学与光电工程学院,安徽合肥230009

出　　处：《光学学报》2023年第20期216-223,共8页Acta Optica Sinica

基　　金：国家重点研发计划项目(2021YFB3602500,2021YFB3602502);国家工程技术研究中心开放课题项目(OCM-2020-03)。

摘　　要：传统具有单片换能器结构的声光偏转器存在布拉格带宽与衍射效率的权衡关系。为了增加布拉格带宽而又不降低衍射效率,提出一种基于双片锯齿电极的换能器结构的声光偏转器。首先采用双片换能器结构实现超声跟踪,使超声波方向能随频率改变,提高布拉格带宽。在此基础上应用锯齿形电极增大超声波的发散程度,进一步提高布拉格带宽。仿真结果表明,电极的锯齿边缘使声波波动性增大,即增大了超声波的发散程度。实验结果表明,在相同实验条件下,具有双片锯齿电极换能器结构的声光偏转器的3 dB带宽比单片矩形电极换能器结构的声光偏转器高62.5%。Objective Acousto-optic deflectors,which constitute a class of precision optical functional components,play a central role in modern optoelectronics technology owing to their excellent performance.Bandwidth,a key performance indicator,determines the frequency range of these devices.Conventional acousto-optic deflectors with single transducer structures face challenges related to bandwidth and diffraction efficiency.To increase the bandwidth,the transducer length must be reduced;however,this may lead to low diffraction efficiency.Therefore,the influence of transducer length on diffraction efficiency and bandwidth must be considered to maintain a balance between the two factors when designing an acoustooptic deflector.The proposed ultrasonic tracking technique addresses this challenge and provides simultaneous improvements in bandwidth and diffraction efficiency.Further optimization of the device's performance requires investigation of additional methods that can ensure high diffraction efficiency while enhancing bandwidth.Methods This paper proposes a design method that enhances the bandwidth of an acousto-optic deflector while maintaining high diffraction efficiency.Utilizing the principle of ultrasonic tracking,the proposed method employs two transducers in series to form an antiphase drive.This configuration generates an ultrasonic beam that can change its propagation direction according to frequency,enabling the device to achieve Bragg diffraction over an extended frequency range,thereby improving ultrasonic energy utilization and increasing Bragg bandwidth.By maintaining the same acoustooptical interaction area for single-and double-blade transducers,the overall transducer length remains constant,ensuring high diffraction efficiency.Additionally,the surface electrode of the two-piece transducer features a serrated design,which further enhances ultrasonic wave dispersion and Bragg bandwidth.To validate this method,the phase distribution of the acoustic field generated by the serrated and rectangular electrodes

关 键 词：声光偏转器 超声跟踪 锯齿电极 布拉格带宽 衍射效率 

分 类 号：TN65[电子电信—电路与系统]