Ellipsometer light intensity automatic adjusting method and device

The invention provides an ellipsometer light intensity automatic adjusting method and device, and the method comprises the steps: carrying out the integration of a collection point in a set integration time period, and obtaining a light intensity harmonic signal; calculating a Fourier coefficient of a measurement signal according to the set number of sampling points, and when the light intensity signal is saturated or undersaturated, determining and adjusting the integration time of the detector through a light intensity signal threshold, so that the number of frames acquired by the light intensity signal is greater than the Fourier coefficient of the measurement signal. According to the scheme, under the condition that the rotating speed of the motor and the structure of mechanical hardware are not changed, rapid adjustment of the light intensity is achieved by adjusting the integral time, the response speed of automatic adjustment of the light intensity is high, and high signal-to-noise ratio measurement of