【作者】 钟娟娟；

【导师】 陈才和；

【作者基本信息】 天津大学 ， 光学工程， 2005， 硕士

【摘要】 “用于声光波导相位调制的氧化锌薄膜和叉指换能器的理论和实验研究”是国家自然科学基金资助项目“光电集成加速度地震检波器的理论与实验研究”的子课题。光电集成加速度地震检波器是一种崭新的传感器,是利用集成光学与半导体工艺技术,将波导偏振器、光波导、波导相位调制器、光电探测器以及信号处理电路都集成在同一基底上,达到真正的光电集成一体化。本课题创新性提出声光波导相位调制器,利用声光效应实现对该加速度传感器的相位调制,具有调制频带宽、能量密度高、体积小和易集成的特点,为集成光学的相位调制提供了一个新的思路。本文首先从光电集成加速度传感器的工作原理出发,推导了应力应变与加速度的关系,建立了光波的相位变化与加速度的关系;对于声表面波的激励以及传播方式进行了分析,讨论了声光调制及声光衍射原理,深入研究了声表面波对条波导的相位调制。对氧化锌薄膜和叉指换能器进行了优化设计,权衡薄膜厚度与声光频率、声光频率与转换损耗、声光频率与中心指长、叉指对数与薄膜面积之间的关系,获得了最优设计结果,氧化锌薄膜参数为5000×1000×3μm,叉指换能器参数为:叉指对数N=17、中心距l =27.19μm、声光频率f₀=48MHz、中心指长L₀=4.46mm。深入探讨了氧化锌薄膜、叉指换能器的制备工艺,进行了大量的实验研究,找出了最佳的工艺参数;完成了器件的测试研究:微观结构观察、膜厚精确测试、结晶状态测试、表面形貌测试。获得了优良的实验结果:所制备的氧化锌薄膜具有致密性好、表面平整、完全C轴取向的特点,是一个优良的单轴晶体薄膜;所制备的叉指换能器具有光滑、平整、形貌清晰等特点,因此可望获得传输损耗小、转换损耗低、性能优良的声表面波器件。更多还原

【Abstract】 “Theory and experimental studies on ZnO thin film and IDT using opticwaveguide phase modulator driven by a SAW” is the sub-project of “Theoretical andexperimental research on photo-electronic integrated acceleration Seismic Geophone”supported by Natural Science Foundation of China.photo-electronic integrated acceleration Seismic Geophone is a kind of sensor。The polarizer、optic waveguide、phase modulator、PIN and signal processing circuithave been integrated on the same substrate using the technology integrated optics andsemiconductor., A kind of novel optic waveguide phase modulator driven by a surfaceacoustic wave（SAW）, applied to the signal modulation of photo-electronic-integratedaccelerator using acoustooptic interaction, has been presented in this dissertation. Thismodulator can offer several advantages: ripe preparation technology, high operatingfrequency, long interaction distance, high energy density, small bulk andeasy-integrated, and create a new thinking for the modulation of integrated optics.Staring with the theory of photo-electronic integrated acceleratetion sensor, therelation between stress-strain and acceleration is addressed, and hence does therelation and the phase change;then the theory of the modulation is analyzed. Theprompting and the transfers of the SAW have been researched, and the basic theory ofthe acoustooptic modulation and acoustooptic interaction is analyzed deeply. Throughstudying the theory of acoustooptic modulating in detail, we design the ZnO thin film’and IDT’ structure and fabrication parameter. And we get the optimization bybalancing the thickness of the thin film and the frequency of the SAW、the frequencyof the SAW and the conversion loss、the frequency of the SAW and the electrodeaperture width、the IDT pairs and the area of the thin film. The main designparameters of the modulator is as following: the ZnO thin film with the dimensions of5mm×0.8mm×0.003mm;IDT with the fingers of 17 pairs, the SAW frequency off₀=48MHz, the electrode aperture width of L₀=4.46mm and interdigital periodl =27.19μm .Every technological link which fabricates the ZnO thin film and IDT is discussedin detail, and great deals of experimentation have been done and the optimalparameters of arts have been found. Then we make a series of test including of theobserving of the microstructure、the fine measure of the film thickness、the directionof the crystal axes. The experimental results are quite satisfactory: the high qualityZnO thin film was developed. Being a fine qusi-single crystal thin film, it isabsolutely C-axis oriented and has many good characteristics, such as highcompactness and excellent surface smoothness. As a result, the IDT we obtained isgood in terms of smoothness, flatness and surface features. It is probable to fabricatesteady frequency properties, low propagation loss, low conversion loss and excellentcapability SAW devices.更多还原