光电反馈垂直腔表面发射激光器双稳特性的研究

发布时间：2018-03-20 21:20

本文选题：偏振双稳(PB)　切入点：光电反馈　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：垂直腔表面发射激光器(vertical cavity surface emitting lasers,VCSELs)因有源区小,阈值电流低,易集成二维激光阵列,造价低廉以及容易与光纤耦合等优点而受到广泛的关注。特别地,VCSELs有源区的圆形对称结构和各向异性的增益材料导致它的基横模具有较差的偏振稳定性,当偏置电流、温度等参量改变时,两相互正交的偏振分量(X-PC和Y-PC)可能发生相互转换,即出现偏振开关(PS)。此外,研究表明VCSELs在光反馈、光注入等外部扰动下也会发生PS现象,且当电流、反馈强度等系统参量沿不同路径变化时,系统在相同的参量下两正交偏振分量输出的能量可能不同,即出现偏振双稳(PB)现象。VCSELs这种PB现象在光学逻辑开关、光互连、光存储等领域具有巨大的潜在应用价值。目前,关于外部扰动下VCSELs的偏振双稳特性研究主要集中在光反馈和光注入的情况,而光电反馈情况的研究相对较少。因此,本文实验研究了光电正反馈和光电负反馈两种情况下1550 nm-VCSEL的偏振双稳特性,讨论了反馈强度对PS的开关点电流大小和PB宽度的影响。研究结果表明:自由运行1550 nm-VCSEL在逐渐增加或逐渐减少注入偏置电流的过程中会发生I类PS或II类PS,且这两种类型PS的开关点出现在不同的电流值处,即自由运行1550 nm-VCSEL可呈现出偏振双稳(PB)特性;引入光电正反馈后,两类PS的开关点电流将随反馈强度的变化而有所改变,当反馈强度相对较小时,I类PS和II类PS的开关点电流几乎与自由运行的情况保持一致,随着反馈强度的增加,两类PS开关点电流将发生改变,且双稳环宽度呈现出逐渐减小的趋势;引入光电负反馈后,随着反馈强度的加大,I类PS和II类PS的开关点电流总体向更小电流方向移动,但变化趋势相对复杂,其双稳环宽度总体上呈现下降的趋势,且下降过程中伴随着较大波动。
[Abstract]:Vertical cavity surface emitting lasers (VCSELs) have small source region and low threshold current, so it is easy to integrate two-dimensional laser arrays. The advantages of low cost and easy coupling with optical fiber have attracted wide attention. In particular, circular symmetric structure and anisotropic gain materials in the active region of VCSELs lead to poor polarization stability of the base transverse mold, when the bias current, When the temperature and other parameters are changed, the two orthogonal polarization components (X-PC and Y-PC) may be converted to each other, that is, the polarization switch may occur. In addition, the study shows that the PS phenomenon also occurs in VCSELs under external disturbances such as optical feedback and optical injection, and when the current, When the system parameters such as feedback intensity change along different paths, the output energy of the two orthogonal polarization components of the system may be different under the same parameters, that is, the phenomenon of polarization bistable PB.VCSELs, such as PB phenomenon in optical logic switch, optical interconnection, Optical storage and other fields have great potential application value. At present, the research on polarization bistability of VCSELs under external disturbances is mainly focused on the case of optical feedback and optical injection, but the research on optoelectronic feedback is relatively rare. In this paper, the polarization bistability of 1550 nm-VCSEL is experimentally studied under both optoelectronic positive feedback and optoelectronic negative feedback. The effect of feedback intensity on the switching current and PB width of PS is discussed. The results show that class I PS or PSII will occur in the process of increasing or decreasing the injection bias current during the free operation of 1550 nm-VCSEL. Two types of PS switch points appear at different current values, That is, the free operation of 1550 nm-VCSEL can show polarization bistable PBs, and the switching point current of the two kinds of PS will change with the change of feedback intensity after the introduction of optoelectronic positive feedback. When the feedback intensity is relatively small, the switching point current of Class I PS and Class II PS is almost the same as that of free operation. With the increase of feedback intensity, the switching point current of the two kinds of PS will change. The width of bistable ring is decreasing gradually, the switching point current of Class I PS and Class II PS moves towards smaller current with the increase of feedback intensity, but the change trend is relatively complex. The width of the bistable ring is decreasing and fluctuating.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248

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