Automatic calibration optical interferometer and automatic calibration method of optical interferometer

An automatic calibration optical interferometer, comprising:

• a light source configured to emit a low coherent light;
• an optical interference assembly coupled to the light source and configured to divide the low coherent light into a first incident light and a second incident light;
• an optical sampling assembly coupled to the optical interference assembly, wherein the optical sampling assembly comprises a first end and a second end, the first end couples to the optical interference assembly to receive the first incident light, the second end is configured to face a test sample, a partially reflective window at the second end is configured to divide the first incident light into a first reflected light and a first penetrating light, and the first penetrating light is configured to be emitted to the test sample;
• an optical reference assembly coupled to the optical interference assembly, wherein the optical reference assembly comprises a reference mirror and an actuator, the optical reference assembly receives the second incident light and emits the second incident light to the reference mirror so as to generate a second reflected light, and the actuator is configured to move the reference mirror;
• a polychromator coupled to the optical interference assembly, wherein the polychromator is configured to output a displacement signal according to an optical path difference variation between the first and second reflected lights;
• and
• a displacement controller electrically connecting to the polychromator and configured to control the actuator according to the displacement signal, wherein the second reflected light is added up by the optical path difference variation between the first and second reflected lights.