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用干涉法测量光波长移动所产生的相位，是光纤布喇格光栅解调系统等光电传感系统中广泛采用的测量技术。本文对采用该方法所引入的测量原理误差进行理论分析和计算机仿真。在光纤布喇格光栅传感系统中，直接用锁相放大器测量布喇格波长移动所对应的相位变化时，如果布喇格波长与其相关的锯齿波光程差幅值不相等，将产生准周期性的测量原理误差。假设锯齿波的初始偏差为２０ｎｍ，那么测量原理误差将大到全量程的５％。如果使用双相锁相放大器，并且用于测量交变的应变等交变参量，其测量原理误差将减小到全量程的０．４％以内。
Measuring the phase produced by the wavelength shift of light using the interferometry is a widely used measurement technique in photoelectric sensing systems such as fiber Bragg grating demodulation systems. In this paper, the measurement principle error introduced by this method is analyzed theoretically and computer simulation. In the fiber Bragg grating sensing system, the direct phase lock-in amplifier to measure the Bragg wavelength shift corresponding to the phase change, if the Bragg wavelength and its associated sawtooth wave amplitude difference is not equal, will produce quasi-periodic The principle of measurement error. Assuming the initial deviation of the sawtooth wave is 20 nm, the measurement principle error will be as large as 5% of the full scale. If a dual-phase lock-in amplifier is used and is used to measure alternating parameters such as alternating strain, the measurement principle error will be reduced to within 0.4% of full scale.