在飞秒激光频率梳系统中,通常采用自参考技术测量飞秒激光脉冲的载波包络相移,但该技术需要采用光子晶体光纤进行光谱扩展从而增加了系统的不稳定性,这种技术已经制约了高稳定度的飞秒激光频率梳的发展.采用PPLN晶体差频法测量了宽谱钛宝石振荡器输出的7fs激光脉冲的载波包络频移,得到了大于30dB的拍频信号,为研制无光纤的新一代高稳定度光学频率梳奠定了基础. In femtosecond laser frequency combing systems, the carrier envelope phase shift of femtosecond laser pulses is usually measured using a self-reference technique, but this technique requires spectral expansion using photonic crystal fibers to increase system instability, which has been Which restricts the development of the high stability femtosecond laser frequency comb.The frequency shift of the 7fs laser pulse output from the broad-spectrum Ti: sapphire oscillator was measured by the PPLN crystal difference frequency method, and the beat frequency signal of more than 30dB was obtained as The development of a new generation of fiber-optic high-stability optical frequency comb has laid the foundation.