摘要
建立了由光纤激光器阵列、薄透镜和衍射光栅组成的频谱叠加理论模型,基于高斯光束的变换和衍射理论,推导出远场光强分布的关系式,探讨了系统参量的优化设计并进行了数值模拟。结果表明:当中心波长激光器的-1级干涉主极大与槽面衍射主极大重合、零级干涉主极大刚好落在槽面衍射的+1级零值极小上、其它波长激光器的-1级干涉主极大与中心波长激光器的槽面衍射主极大重合时,输出光束的衍射效率较高;当光栅平面法线与薄透镜光轴的夹角为衍射光栅槽形角的一半时,输出光束的半角宽度较小。
The theoretical model of spectral beam combining of fiber lasers is presented. It includes a fiber laser array, a lens and a diffraction grating. Based on the conversion and diffraction theories of Gaussian beam, far-field optical intensity expression is derived, and the systemic parameters are optimized. Numerical results show that diffraction efficiency can be improved by over- lapping the negative first-order interference principal maximum and the zeroth-order diffraction maximum of the central-wave- length-laser, overlapping the zeroth-order interference principal maximum and the first-order diffraction minima of the central- wavelength-laser, and overlapping the negative first-order interference principal maximums of other lasers and the zeroth-order diffraction maximum of the central-wavelength-laser. The angular width can be reduced by making the grating normal an angle of half blazed angle with the axis of lens.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2007年第5期723-727,共5页
High Power Laser and Particle Beams
基金
湖北省科技攻关计划项目资助课题(2005AA101B10)
关键词
频谱组束
衍射光栅
光纤激光器
高斯光束
非相干组束
Spectral beam combining
Diffraction grating
Fiber lasers
Gaussian beams
Incoherent beam combining
