photon echo

例句：

1. 1.The photon echo from the distant star was so faint that it was barely detectable.
   远处恒星的光子回声如此微弱，几乎无法察觉。
2. 2. The team used a special device to capture the photon echo of the ancient ruins.
   团队使用了一种特殊设备来捕捉古遗迹的光子回声。
3. 3.The researcher analyzed the photon echo signals to determine the location of the alien spacecraft.
   研究员分析了光子回声信号以确定外星飞船的位置。