Proof of distributed feedback was the tuning of the laser wavelength over 130°A by changing the grating period, and the absence of shift in wavelength with increasing excitation current. 存在分布反馈的证据是，改变光栅周期可使激光波长在130°A范围内变化以及波长不随激发电流的增大而移动。
The dependences of gain bandwidth on crystal length and pump intensity are also studied.Selecting appropriate grating period, wider tunable range can be obtained with group velocity matching. 选择合适的光栅周期，能获得调谐范围较宽的群速匹配脉冲参量放大，参量带宽与晶体长度、非共线角及群速色散有关。
