Grouping mode-hopping time domain modulation method and Fourier mode-locked laser

Abstract

The invention provides a grouped mode-hopping time domain modulation method and a Fourier mode-locked laser, and the method comprises the steps that a sweep frequency filtering unit is connected witha first drive signal, an intensity modulation unit is connected with a second drive signal synchronously, and the second drive signal is provided with N groups of unidirectional pulse sequences or 2Ngroups of bidirectional pulse sequences; the first driving signal drives the sweep frequency filtering unit to work at the N resonance values to obtain a sweep frequency signal; a swept-frequency signal passes through the light amplification unit, the light beam splitting unit, the light delay unit and the polarization control unit and then enters the intensity modulation unit, and a second driving signal drives the intensity modulation unit to perform grouping chopping on the swept-frequency signal after the polarization state is adjusted; the intensity modulation unit generates N groups of unidirectional swept-frequency signals or 2N groups of bidirectional swept-frequency signals with the same free spectral range, and the free spectral range becomes 1/N or 1/2N of the original free spectral range. According to the invention, a relatively small free light range is obtained, and the frequency sweeping speed of the Fourier mode-locked laser is improved by N times. 本发明所提供的一种分组跳模时域调制方法及傅里叶锁模激光器，包括：扫频滤波单元接入第一驱动信号，强度调制单元同步接入第二驱动信号，第二驱动信号中具有单向N组脉冲序列或双向2N组脉冲序列；第一驱动信号驱动扫频滤波单元工作在N次谐振值得到扫频信号；扫频信号经光放大单元、光分束单元、光延迟单元、偏振控制单元后进入强度调制单元，第二驱动信号驱动强度调制单元对调节偏振状态后的扫频信号进行分组斩波；强度调制单元产生自由光谱范围相同的单向N组扫频信号或双向2N组扫频信号，自由光谱范围变为原来的1/N或1/2N。本发明获得了较小的自由光范围，同时将傅里叶锁模激光器的扫频速度提高N倍。