【摘要】 基于相位测量的外差干涉系统以其信号处理方面的优势在光学计量领域得到了广泛的应用。介绍了采用机械调制方法的差动单频干涉系统的干涉信号小数级次的相位测量实现方法。针对机械调制干涉系统的信号有相位跃变点且周期不均匀的特点 ,提出了利用外触发信号对干涉信号进行整周期截取而后再鉴相的方法。研制了基于 FPGA的外触发式差动数字鉴相系统。实验测试表明 ,该鉴相系统在信号频率为 30 0 Hz～ 10 k Hz范围内达到的指标为 :示值稳定性优于± 0 .0 15°,极限偏差小于± 0 .0 7°更多还原

【Abstract】 Heterodyne interferometric system based on phase measurement can be widely used in the optical metrology fields owing to its advantages of signal processing method In this paper, the phase measurement method to determine the fraction of the interference fringe modulated by a PZT in a differential single frequency interferometer is investigated In order to overcome the problem of phase jump and asymmetry in period of the signal modulated by a PZT in the interferometer, a differential phase discrimination method with an outer trigger signal is presented The phase measurement system is carried out utilizing Field Programmable Gate Array (FPGA) device It is testified by experiments that at a frequency range of 300Hz～10kHz, the phase measurement system has a stability of ±0 015° and a maximum error of ±0 07°更多还原