光纤激光频谱组束的仿真研究

基于利用透射体布拉格光栅 准直透镜所设计的非相干组束方案,建立了光纤激光组束的理论模型.依据所建模型,对光栅的组束效果进行了分析.结果表明:最佳组束时,不同的光栅厚度须选择不同的光栅参数;随着光栅厚度的减小,满足最佳组束条件的空间频率和折射率调制将逐渐增大;在折射率调制和空间频率不变的情况下,随着光栅厚度的减小,角或谱的选择性逐渐增大;随着光束发散角和光谱宽度的增大,衍射效率逐渐减小.

Simulation Study on Spectral Beam Combining of Fiber Lasers

Based on a scheme for incoherent beam combining designed with transmitting volume Bragg grating and collimating lens,spectral beam combining of fiber lasers was modeled.On the basis of the model,the combining effect is analyzed.The simulation results show that different parameters must be selected for different grating thickness.The thinner the grating,the greater spatial frequency and refractive index modulation are needed for the optimal combining.Both spectral and angle selectivity widen gradually with decrease of grating thickness under the same refractive-index modulation and spatial frequency.In addition,diffraction efficiency of grating decreases gradually with increase of beam divergence and spectral width.