【单选题】26 / 52两个周期相差很小的进波叠加后,单个波的波长由哪个因子决定?A4π/(k+k′)4\pi/(k+k')4π/(k+k′)正确B4π/(k−k′)4\pi/(k-k')4π/(k−k′)C2π/k2\pi/k2π/kD2π/(k−k′)2\pi/(k-k')2π/(k−k′)参考答案A参考解析波长 4π/(k+k') 的单个波(K8−17K8-17K8−17)。