With ordinary photocells, one can pick up the frequency between two different lasers.

用普通光电池，人们就能够探测到两个不同的激光之间的拍频。

youdao

With ordinary photocells, one can pick up the frequency between two different lasers.

用普通光电池，人们就能够探测到两个不同的激光之间的拍频。

youdao