腔面反射对锥形激光器光束质量的影响  

Effect of Facet Reflection on Beam Quality of Tapered Laser

作　　者：游道明 谭满清[1,2] 陈文彬 刘维华 You Daoming;Tan Manqin;Chen Wenbin;Liu Weihua(State Key Laboratory of Integrated Optoelectronics,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;College of Materials Science and OptoElectronic Technology,University ofChinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院半导体研究所集成光电子学国家重点实验室,北京100083 [2]中国科学院大学材料科学与光电技术学院,北京100049

出　　处：《中国激光》2023年第2期29-37,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(61935018)。

摘　　要：高功率下光束质量恶化问题制约着锥形激光器的发展,基于腔面光学薄膜,研究了腔面反射对光束质量的影响。建立了不包含抗反射结构的物理模型,采用锥形激光器的电光模型进行仿真,分析了不同腔面反射率下器件的光场分布。结果表明,在传统锥形激光器中,存在强烈的光泵、光束成丝、自聚焦和空间烧孔效应,来自腔面的剩余反射引发了上述非线性效应,最终影响光束质量。前腔面反射在此过程中起着关键作用,后腔面同样对光束质量有较大影响。通过优化腔面反射率,提出了两种优化路径,部分设计的光束质量因子小于2,实现了高光束质量。研究结果为锥形激光器的设计提供了参考。Objective Tapered lasers undergo severe beam quality deterioration under high powers.Optical pumping,selffocusing,spatial hole burning,and beam filamentation are some phenomena that occur in traditional tapered lasers,severely degrading the beam quality.Facet reflection causes these problems,but the specific influence mechanism of facet reflection on beam quality is unclear.This study aims to clarify the effect of facet reflection on the beam quality of tapered lasers and proposes an optimization scheme to improve the beam quality.Methods Based on facet coating,this study establishes a physical model of a tapered laser without an antireflection structure.By varying the reflectivity of the front and rear facets and using the electro-optic model of the tapered lasers for simulations,the optical field distributions at different positions in the transmission direction in the facet are analyzed.In addition,the effect of facet reflection on the beam quality of the tapered laser is investigated.The output characteristics and beam quality factor of the optimized design are also verified using the simulation method.Results and Discussions In traditional tapered lasers,phenomena such as optical pumping,spatial hole burning,and beam filamentation cause the beam quality to deteriorate rapidly under high powers(Fig.3).The residual reflected light on the front facet is transmitted in the tapered waveguide,and the optical field exhibits a significantly uneven distribution.With a decrease in the reflectivity of the front facet,the side lobes are suppressed.When the reflectivity of the front facet decreases below 1%,the light-field distribution tends to be stable.In particular,when the reflectivity of the front facet is0.01%,the beam intensity in waveguide increases significantly(Fig.4).The reflectivity of the rear facet directly induces an optical pumping effect.Reducing the reflectivity of the rear facet can weaken the optical pumping in the cavity(Fig.5).Combined with the optimization of the front facet reflection,the mode cha

关 键 词：激光器 锥形激光器 腔面反射 光学薄膜 光束质量 

分 类 号：TN248.4[电子电信—物理电子学]