约定光路自左向右。发射平面<img src="https://static.pphuashu.com/wangke/imgs/topic/2e26230362bb504758fdd7f58f513aef.png.png.png"/>在接收平面<img src="https://static.zxtiku.com/wangke/imgs/topic/96b1d9456236540c7560a6692910cab2.png"/>左侧，两者纵向距离<img src="https://static.zxtiku.com/wangke/imgs/topic/bf6438ff2e2917059c7b6e36dcec57d8.png"/>。在发射平面上有三个点源，其横向位置坐标<img src="https://static.zxtiku.com/wangke/imgs/topic/f6aa5e8ccefdd79d40bde573fee5d860.png"/>分别为<img src="https://static.zxtiku.com/wangke/imgs/topic/781e213eae0bb323a1abdd3a0d118200.png"/>，<img src="https://static.zxtiku.com/wangke/imgs/topic/5c7bc848ed08fb7a2831bd785f51e763.png"/>和<img src="https://static.zxtiku.com/wangke/imgs/topic/16d9a9c584dfd80b8e4dc022bf3abbba.png"/>，且同相位。<br/> 1）设其波矢的绝对值均为<img src="https://static.zxtiku.com/wangke/imgs/topic/3321e3de5f7f473e80b736308566eaa2.png"/>,振幅均为<img src="https://static.zxtiku.com/wangke/imgs/topic/01dd02947e4fb20041aa157485eab9d4.png"/>。这三个点源所产生的波前函数为。