An ultrafast ellipsometer device and measurement method

Abstract

The invention discloses an ultrafast ellipsometer and a measuring method. The ultrafast ellipsometer comprises a chirped pulse generation unit used for generating picosecond-order chirped pulse, a pump light path unit, a probe light path unit and a reflected light path unit, wherein the chirped pulse is divided into pump light and probe light after passing through an unpolarized spectroscope, the pump light carries out pump impact on a sample via the pump light path unit, the probe light is obliquely incident on the surface of the sample via the probe light path unit, and reflected light obtained after reflection of the probe light by the surface of the sample is divided into light P and light S. The light P and the light S are allowed to undergo interference so as to produce a frequency domain interferogram; changes of the polarization states of polarized light, including amplitude ratio and phase difference, are calculated according to the frequency domain interferogram; and impact dynamic and optical parameters are obtained by subjecting theoretical expressions of the amplitude ratio and phase difference of the polarized light and measuring results to fitting. According to the invention, the impact dynamic characteristic and optical characteristics of a material are measured at the same time by using single-shot pulse, and the response characteristics of the material under the action of impact waves can be accurately described.

Description

technical field [0001] The invention belongs to the field of ultrafast measurement, and more specifically relates to an ultrafast ellipsometer device and a measurement method. Background technique [0002] Studying the dynamic response characteristics of materials under extreme conditions such as high pressure and high strain rate is a frontier topic in the field of material physics, and shock wave loading is an important technical means to generate such extreme conditions inside materials. Since the generation and disappearance of shock waves takes place in an extremely short time of tens to hundreds of picoseconds, the measurement of shock dynamics places very high demands on the time resolution of the test technology. When a shock wave propagates in a material, the study of the shock wave and the response characteristics of the material usually requires the measurement of the dynamic parameters of the material, such as the shock wave velocity, the particle velocity after ...

AI Technical Summary

Problems solved by technology

These methods can increase the time resolution to the level of picoseconds or even femtoseconds, but they can only measure the displacement of the reflective surface, and cannot measure the optical properties of the material, so they cannot give the impact dynamic process from the internal structure and performance changes of the material. Moreover, these measurement methods are all discrete point measurements, and the repeatability of the experimental conditions affects the accuracy of the measured experimental data, resulting in large errors.

Images