光纤激光阵列自组织相干合成的性能研究

Coherent combining of evanescent coupled fiber laser array

研究了基于倏逝波耦合的自组织相干合成激光阵列。应用静态"本征模/超模"理论推导阵列模式;通过数值方法考察阵列激光系统的动态特性进而分析输出功率的稳定性、阵列的扩展能力和阵列模式;并对两种方法得到的阵列模式进行了比较分析。结果表明:输出功率的稳定性以及输出功率的大小受阵列的锁相性能和阵元间的相位差影响;随着激光单元数目的增加,阵列总输出功率会非线性增大。通过跟踪各个阵元的相位变化并考察阵列模式的近场和远场特性,初步验证了37单元阵列的相干合成,随着阵元数目的增加,中心阵元与其邻近层阵元的振幅差会逐渐减小。

Evanescent coupled fiber laser array was described and studied.Array modes were derived by applying the static eigenmode/supermode theory.The stability of output power,the array scalability and the array mode were analyzed by numerically studying the dynamical characteristics of the laser array system.The array modes based on the above two methods were compared and analyzed.The results show that the output power level and the power stability are directly affected by the phase locking property and the relative phase errors respectively.With the increase of laser elements,the total output power of the array increases nonlinearly.By tracking the phases of array elements and examining the laser array property in both near and far fields,the evidence that at least 37 fibers can be coherently combined,is given.With the increase of fiber elements,the power differences between central element and its neighbors become smaller gradually.