干涉测量技术被广泛应用于纳米级的微观形貌测量，为了提高干涉测量的精度和灵敏度，提出一种基于白光干涉和激光二次干涉相结合的高灵敏度零差干涉测量方法。设计了高灵敏度零差干涉系统，利用激光二次干涉的零点对白光干涉的暗纹进行定位，使其在零光程差时达到斜率最大值。利用波动原理和干涉条纹的强度公式分别对白光信号和激光信号进行分析，并提出将白光和激光干涉信号相结合的灵敏度计算方法。对系统及其灵敏度进行了仿真，最后搭建光路，将白光干涉条纹调至暗纹位置，以此来定位激光二次干涉的零位，并进行数据采集。所述测量方法的灵敏度相比激光二次干涉至少提高1 832倍，相应的测量不确定度仅为±0.288 7 mV。所述测量系统能够有效解决传统干涉测量中计算量大的问题，灵敏度高、稳定可靠。

Interferometry is widely used in nano-scale micro-topography measurement. In order to improve its accuracy and sensitivity, a high-sensitivity homodyne interferometry based on white light interference and laser secondary interference was proposed. A high-sensitivity homodyne interferometry system was designed, and the zero point of the laser secondary interference was used to locate the dark striation of white light interference, so that it could reach the maximum slope when optical path difference was zero. The signals of white light and laser were analyzed by using the wave principle and intensity formula of interference fringes, and a sensitivity calculation method based on the combination of white light and laser interference signal was proposed. The system and its sensitivity were simulated. Finally, the optical path was built, and the white light interference fringes were adjusted to the dark striations position, so as to locate the zero position of laser secondary interference and carry out the data acquisition. It is showed that the sensitivity of the measurement method is at least 1 832 times higher than that of the laser secondary interference, and the corresponding measurement uncertainty is only ±0.288 7 mV. The measurement system can effectively solve the problem of large amount of calculation in traditional interferometry, and has high sensitivity, stability and reliability.