IFFabbr.当且仅当(=if and only if)IFF.abbr.敌我识别器(=Identification；Friend or Foe)IFFAn.国际电影资料馆联合会

1. The light is emitted by the laser diode and enters a diffraction grating.
   激光束从激光二极管中发出，射入衍射光栅。
2. When the laser beam goes through the diffraction grating, it is split up into a central bright beam plus a number of side beams.
   当激光束射入衍射光栅后，被分成一个中间的明亮光束和一些处于旁边的光束。