Laser interferometry velocimetry with high spatiotemporal resolution based on spatial dispersion

With the development of shock wave physics, the study of shock compression response characteristics of materials at micromesoscopic scale has been gradually deepened, which also puts forward higher performance and more dimension requirements for the diagnostic technology of transient velocity measurement. The microstructure of the surface of the material and the internal defects are usually in the scale range of tens to hundreds of micrometers, which requires high spatiotemporal resolution measurement technology. A multi-wavelength narrow linewidth CW laser was designed and a spatial dispersion probe was developed to achieve high spatial resolution measurement in a single optical fiber, which breaks through the existing close-packed scattered point measurement shortboard. By using the mapping relationship between the frequency domain and the space domain, the breakthrough of laser interferometric velocimetry technology in the three dimensions of time domain, frequency, and space domain is realized. The spatial frequency domain laser interferometry with a spatial resolution better than 35 microns provides technical support for the experimental study of the physical properties of high-pressure materials with higher dimensions and higher precision.