基于液晶空间光调制器的脉冲整形系统校准及应用

Calibration and Application of Optical Pulse Shaping System based on Liquid Crystal Spatial Light Modulator

搭建了反射式光脉冲整形系统,通过改变加载到液晶空间光调制器各像素点的调制电压,测定系统分辨率及调制电压与输出信号光强和相位变化的关系,并对液晶空间光调制器进行校准.实验结果表明:光强随调制电压周期变化,相位随调制电压非线性变化;系统分辨率为10GHz,像素调制间隔为0.08nm,即能够实现对频率间隔10GHz的光信号的调制.应用该系统,以谱线间隔为10GHz的光学频率梳为信号源,对脉冲频谱进行整形,产生了平坦、高斯型、三角、倒三角及光学频率梳信号.

A reflective optical pulse shaping system based on liquid crystal spatial light modulator was built. With changing the modulation voltage loading into the pixel on the liquid crystal spatial light modulator, the system resolution and the relationship between the output including intensity and phase and the modulation voltage were measured. And the modulator＇s calibration was discussed. The resules show that the intensity changes with modulation voltage linearly, while the phase is nonlinear. The frequency resolution of pulse shaping system is 10 GHz, corresponding 0.08 nm wavelength resolution, which can realize the modulation of optical signal with frequency interval of 10 GHz. An optical frequency comb with 10 GHz spectral spacing was adoped as the light source. Spectrum shaping was performed and flat spectrum, Gaussian spectrum, triangular spectrum and inverted triangle spectrum were generated experimentally.