吕林杰, 武腾飞, 韩继博, 赵力杰, 马鹏谋, 陈相淼. 时间拉伸光子多普勒测速技术研究[J]. 红外与激光工程, 2022, 51(9): 20210809. DOI: 10.3788/IRLA20210809
引用本文: 吕林杰, 武腾飞, 韩继博, 赵力杰, 马鹏谋, 陈相淼. 时间拉伸光子多普勒测速技术研究[J]. 红外与激光工程, 2022, 51(9): 20210809. DOI: 10.3788/IRLA20210809
Lv Linjie, Wu Tengfei, Han Jibo, Zhao Lijie, Ma Pengmou, Chen Xiangmiao. Research on time-stretched photon Doppler velocimetry[J]. Infrared and Laser Engineering, 2022, 51(9): 20210809. DOI: 10.3788/IRLA20210809
Citation: Lv Linjie, Wu Tengfei, Han Jibo, Zhao Lijie, Ma Pengmou, Chen Xiangmiao. Research on time-stretched photon Doppler velocimetry[J]. Infrared and Laser Engineering, 2022, 51(9): 20210809. DOI: 10.3788/IRLA20210809

时间拉伸光子多普勒测速技术研究

Research on time-stretched photon Doppler velocimetry

  • 摘要: 在瞬态高速测速场景中,目标物体在几十ns时间内能加速到几~几十km/s,因此光子多普勒测速系统中电学数模转换器件带宽要求达到GHz甚至上百GHz。时间拉伸光子多普勒测速系统利用飞秒激光时间拉伸特性,在光域中完成信号降频处理,降低了光电信号探测器件和电学数模转换器件带宽压力。提出了改进的时间拉伸光子多普勒测速系统,飞秒脉冲经过第一级色散器件充分展宽铺满整个时域,避免了速度信号的采样间断;信号解调上采用误差补偿算法对频移信号进行补偿,减小了因为位移引入的系统误差,从而增加了有效记录时间。实验使用纳秒激光驱动铝膜产生高速飞片,测试了文中测速系统在记录时间1.2 µs内的实验效果。实验使用重频50 MHz飞秒光源,第一级和第二级色散器件分别使用200 km和100 km单模光纤,构成比例因子2/3。最终实验表明系统将3.6 GHz的多普勒频移信号降低为2.4 GHz,通过与光子多普勒测速系统进行结果比对,实验动态误差小于5%。该系统将能够应用于多种动高压技术加载飞片场景下的速度进行测量,为瞬态高速测量领域提供了新的测量手段。

     

    Abstract: In the transient high-speed velocity measurement scene, the target accelerates to several-tens of km/s in tens of ns. Therefore, the Doppler frequency shift can reach GHz or even hundreds of GHz. The velocity measurement range of photon Doppler velocimetry was limited by the current electrical digital to analog conversion technology. The time-stretched photon Doppler velocimetry used the time-stretched characteristic of femtosecond laser to reduce the signal frequency in the optical domain, which reduced the pressure of photoelectric signal detector and electrical digital-to-analog conversion device. An improved time-stretched photon Doppler velocimetry system was proposed in this paper. The femtosecond pulse was fully widened and spread over the whole time domain through the first stage dispersion fiber, in order to avoid the sampling interruption of velocity signal; In signal demodulation, error compensation algorithm was used to compensate the frequency shift signal, which reduced the system error caused by displacement and increased the effective recording time. Nanosecond laser was used to drive the aluminum film to produce high-speed flyer in the experiment, and the experimental results of the paper speed system were tested in the recording time of 1.2 µs. The repetition frequency 50 MHz femtosecond laser was used in the experiment. The first and second stage dispersion devices used 200 km and 100 km single-mode fiber, forming a scale factor of 2/3. In the end, the experiment showed that the Doppler shift signal of 3.6 GHz was reduced to 2.4 GHz, which was compared with the photon Doppler velocimetry system, and the experimental error was less than 5%. The system will be able to apply velocity measurement under dynamic high pressure technology loading flyer scene, and provides new measures for transient high-speed measurement area.

     

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