【摘要】 针对光电类课程实验教学需求，提出基于外差干涉技术的铌酸锂薄膜电光系数测量方案．通过外差干涉系统探测施加调制电压引起的薄膜折射率变化，利用贝塞尔函数展开与频谱分析方法解调相位信号，结合多光束干涉效应构建相位调制幅度与电光系数的量化模型，实现电光效应机理的可视化教学与参数精准测量．测得铌酸锂薄膜的电光系数为（19.37±0.25）pm/V，验证了方案的有效性．通过可观测的干涉信号演变与频谱特征直观揭示了电光调制的物理过程，可支撑学生掌握相位调制原理、外差检测技术及电光材料特性分析方法，适用于光电专业综合性实验教学．更多还原

【Abstract】 Addressing the experimental teaching requirements of optoelectronic courses,a scheme for measuring electro-optic coefficient of lithium niobate film was proposed based on heterodyne interferometry.The scheme utilized a heterodyne interference system to detect refractive index changes induced by applied modulation voltage on the film.Phase signals were demodulated using Bessel function expansions and spectral analysis methods.A quantitative model for phase modulation amplitude and electro-optic coefficient was constructed using multi-beam interference effects,facilitating visualized teaching of electro-optic effect mechanisms and precise parameter measurements.Experimental results yieldedγ₃₃=（19.37±0.25）pm/V,validating the effectiveness of the proposed approach.The experimental system visually revealed the electro-optic modulation physical process through observable interference signal evolution and spectral characteristics.This system supported students in mastering phase modulation principles,heterodyne detection techniques,and electro-optic material characteristic analysis methods,suitable for comprehensive experimental teaching in optoelectronic disciplines.更多还原