Coupling efficiency not only affects fiber communication relay distance , but also affects the performance of edfa and semiconductor light amplifier ( sla ) . so it is very important to improve coupling efficiency and reduce its cost . according coupling theory , the coupling of laser diode to single mode fiber is to meet the mode field diameter match and the phase match 它不仅直接影响光纤传输的中继距离，而且对改善ld泵浦掺铒光纤放大器( ldp - edfa ) ， ld泵浦固体半导体激光器( ldp - ssl ) 、半导体光放大( sla )等光通信器件及系统的性能上，在提高他们的性价比有着十分重要的意义。
