An all-fiber chirped pulse velocity interferometer

Abstract

The invention discloses an all-fiber chirped pulse velocity interferometer, comprising a supercontinuous fiber laser, a filter, a fiber isolator, a circulator I, a chirped fiber grating, a fiber beam splitter, a fiber delayer, and a fiber combiner , circulator II, fiber optic probe, fiber amplifier, fiber optic spectrometer; the supercontinuum fiber laser, filter, fiber isolator and circulator I are connected in sequence, and the circulator I is connected with a chirped fiber grating and a fiber beam splitter, and the optical fiber The beam splitter is respectively connected to the fiber beam combiner through the fiber delayer and the fiber jumper, and the circulator II is respectively connected to the fiber beam combiner, the fiber probe and the fiber amplifier, and the fiber amplifier is connected to the fiber spectrometer. The interferometer has a simple structure and is easy to debug. Using this interferometer to measure the speed of a high-speed moving body, the time resolution can reach the level of picoseconds, and its optical path design is conducive to obtaining data with a high signal-to-noise ratio, and the data can be directly reconstructed Speed ​​signal, improve speed measurement accuracy.

Description

technical field [0001] The invention relates to a laser testing device, in particular to an all-fiber chirped pulse velocity interferometer. Background technique [0002] The research on the dynamic response characteristics of materials under the action of strong shock waves is one of the frontier physics topics. It is an important research content to load metal materials with high-power pulsed lasers and accurately measure their free-surface velocity profiles with high time resolution. For the velocity measurement of high-speed moving objects, commonly used diagnostic equipments include velocity interferometer with arbitrary reflective surface (VISAR), all-fiber laser displacement interferometer (DISAR) and laser frequency domain interferometer, among which VISAR uses an expensive fringe camera or oscilloscope As a recording device, limited by the time resolution capability of these devices and other factors, it is difficult for VISAR to achieve time-resolved measurements b...

AI Technical Summary

Problems solved by technology

For the velocity measurement of high-speed moving bodies, the commonly used diagnostic equipment includes the velocity interferometer on any reflective surface (VISAR), the all-fiber laser displacement interferometer (DISAR) and the laser frequency domain interferometer. Among them, VISAR uses expensive streak cameras or oscilloscopes. As a recording device, limited by the time resolution capability of these devices and other factors, it is difficult for VISAR to achieve a time resolution measurement of less than 10 ps; when DISAR is used as a displacement interferometer to measure speed signals, it is difficult for low speeds with very high acceleration Signal measurement is powerless. In addition, considering the data processing process and oscilloscope recording equipment, the speed measurement time resolution of DISAR is usually not lower than 100ps; the laser frequency domain interferometer has unique advantages in measuring high-speed signals. It uses ordinary As a recording device, a spectrometer can achieve picosecond or even sub-picosecond time-resolved measurement. Based on laser frequency domain interferometry technology, the Laser Fusion Research Center of the Chinese Academy of Engineering Physics has applied for two Chinese invention patents: a chirp Pulse velocity interferometer (Patent No. ZL201310706464.X) and an all-fiber frequency domain interferometer (Patent No. ZL201420658771.5), however, the former is composed of discrete optical components, the system is large in size, high in cost, and the debugging process is complicated, while the latter The recorded data is obtained by the interference of two separately transmitted reference light and signal light, which will reduce the signal-to-noise ratio of the data, and the displacement differential operation in the data processing process makes the obtained velocity signal have a strong oscillation, thus Detrimental effect on the accurate interpretation of the speed signal

Images