复合腔锁模激光器超模噪声问题的研究

为了研究复合腔抑制超模噪声的问题,基于传输函数法建立了复合腔等效结构模型,从理论上分析了复合腔主动锁模光纤激光器的结构特性,论证了等效复合腔基频与两子腔腔长的关系。在1GHz射频调制频率下,给出了复合腔各参量与超模噪声的关系。结果表明,复合腔可以减小超模数目,超模噪声的抑制与单腔相比并不具有优势。该结果对复合腔主动锁模光纤激光器的实验研究有一定的参考意义。

Theoretical analysis of supermode noise in mode-locked fiber laser with composite cavity

In order to study the supermode noise suppression in a mode-locked fiber laser with composite cavity,an effective structure model of the composite cavity was built based on the transfer function.The characteristic of an active modelocked ring fiber laser with composite cavity was investigated theoretically.The dependence of the effective basic frequency of the composite cavity on the length of two sub-cavities was demonstrated in detail.Setting the RF modulation frequency at 1 GHz,the relation between the supermode noise and parameters of the composite cavity were listed in a table.It was shown that the number of supermodes was reducedhowever,the reduction of overall supermode noise was not remarkable in comparison with the standard single-cavity configuration.The result is helpful for experimental study of supermode noise of active mode-locked ring fiber laser with composite cavity.