基于光谱控制与色散优化的飞秒啁啾脉冲放大系统

Femtosecond Chirped-Pulse Amplifier System Based on Spectrum Control and Dispersion Optimization

飞秒激光在工业加工、精密测量、军事国防、科学研究等领域具有广阔的应用前景。报道了基于光谱控制与色散优化的高功率、高脉冲质量飞秒啁啾脉冲放大系统。利用与压缩器色散量相匹配的色散可调啁啾布拉格光纤光栅(CFBG)作为展宽器,通过微调CFBG色散量补偿系统的残余色散使整个系统的净色散趋于零;同时引入光谱滤波等手段,保证入射到主放大器之前的脉冲光谱形状不发生畸变,避免了放大过程中脉冲质量的劣化。最终获得了重复频率为50 MHz、平均功率为24 W、脉冲宽度为198 fs的高脉冲质量飞秒激光输出。

Femtosecond laser has many potential applications in various fields,such as industrial processing,precision measurement,defense,and scientific research.A high-power and high-pulse-quality femtosecond chirpedpulse amplifier system based on spectrum control and dispersion optimization is reported.In the proposed system,the chirped fiber Bragg grating(CFBG)with tunable dispersion is designed to match the compressor and can be finetuned.Thus,the net dispersion of the system approaches zero by controlling the residual dispersion of CFBG dispersion compensation system.Furthermore,the degradation of the pulse quality in the amplification processing is avoided by controlling the spectral shape via spectral filtering before the main amplifier to prevent distortion.Finally,high-quality femtosecond laser pulses as short as 198fs with an average power of 24Wat a repetition rate of 50MHz are generated.