Diagnosis Based On Chirped Pulse Shock Wave Frequency Domain Interferometry Techniques

Chirped Pulse Spectral Interferometry (CPSI) is a new optical detection technique which is developing fast recent years. CPSI has the capability of measuring target with ultrafast, high-time-resolution and non-touch. Because of the rapid development in astrophysics, plasma physics and nuclear physics, the time resolution achieved by the traditional instruments is not enough to satisfy the resolution requirement. The technique that has the femtosecond level resolution is then desired and has the potential of wide applications. CPSI, usually be used to obtain characteristic spectral which carried with time-and-displacement data, is based on Fourier optics and Spectral Interferometry. To determinate if CPSI has some advantages in ultrafast measurement, the paper studied the applications about to measure the surface’s time-history of target under pulse-drive-shockwave.First the principles of the Frequency-domain interferometry were discussed and the method of using to measure the motion properties of under-shockwave-target. The methods were then discussed of using gratings to generate chirped pulses and employing spectral components of the chirped pulses to simplify diagnostic process. The performance of CPSI as simulated and the data are compared with the ones predicted by the theory, showing that the difference between two is less than0.0003rad. The time and space synchronization among light fields from the pumped laser, detected laser and reference laser were also analyzed. Experimental system was constructed and the experimental data were captured and processed. A software was then written for analyzing the reconstruction errors. The result shows that the time resolution of the system is within3.7ps and the time frame is within500ps.