提出一种对光脉冲直接相位调制进行光谱展宽的方法,对调制深度、调制信号宽度、同步精度和不同调制信号形状对输出光谱的影响进行了数值模拟。模拟结果表明,调制深度越大,调制信号宽度越小,对光谱的展宽效果越明显,单次调制展宽量越大;不同的调制信号宽度对同步精度有不同的要求,调制信号越窄,对同步精度要求越高;相比于抛物线型调制信号,正弦调制信号会带来光谱两侧明显的幅频调制,降低脉冲可压缩性和再压缩信噪比。实验结果与模拟数值结果相符。 A method of spectral broadening for direct phase modulation of light pulse is proposed. The effects of modulation depth, width of modulation signal, synchronization accuracy and shape of different modulation signals on output spectrum are numerically simulated. The simulation results show that the larger the modulation depth is, the smaller the modulation signal width is, the more obvious the spectrum broadening effect is and the larger the single modulation broadening amount is. The different modulation signal widths have different requirements on the synchronization accuracy, and the narrower the modulation signal is. The higher the synchronization accuracy is required, the sinusoidal modulation signal results in significant amplitude-frequency modulation on both sides of the spectrum compared to the parabolic modulated signal, reducing pulse compressibility and recompressing the signal-to-noise ratio. The experimental results are consistent with the numerical results.