大功率半导体激光器腔面的光学结构优化

采用转换矩阵的处理方法,对大功率半导体激光器腔面光学灾变阈值与膜层结构的关系进行了分析.从理论上给出了膜层的设计方法和计算结果,解释了不同腔面反射率对应的腔光学灾变阈值变化的实验结果,并首次提出后腔面的优化结构以避免后腔面烧毁.     

硫化的激光器腔面上溅射ZnS钝化膜的研究

提出了一种新的激光器腔面钝化方法.先用(NH4)2S溶液硫化解理后的激光器腔面,然后使用磁控溅射方法对激光器的前腔面镀ZnS钝化膜、后腔面镀Si/SiO2高反射膜.ZnS钝化层光学厚度为λ/4,在中心波长为808 nm处透过率可达95.5%.钝化前激光器的光学灾变损伤(COD)阈值为1.6 W,钝化后为2.0 W,提高了25%倍;未镀膜的激光器阈值电流为0.25 A,经硫化再镀ZnS后阈值电流为0.20 A,降低了20%.实验结果表明,经硫化后溅射ZnS对激光器腔面具有良好的钝化和增透效果.     

550 K高温下激光器腔面温度的影响研究

针对激光器长期高温工作时腔面温度急剧升高产生灾变性光学损伤(COD)的问题,文章提出在半导体激光器腔面处加入Al₂O₃膜和陶瓷隔热共同作用,其可以降低激光器腔面温度,防止COD的产生。文章首先建立了半导体激光器简化模型分析固体传热。然后对550 K高温下无镀膜无隔热结构、有镀膜无隔热结构、无镀膜有隔热结构及镀膜与隔热结构共同作用时激光器模型的腔面温度进行仿真。其中镀膜选用Al₂O₃,隔热结构选用陶瓷隔热,腔面材料选用GaAs,热沉选用Cu热沉,接触层选用AlGaAa。4组对比实验结果表明,镀膜与隔热结构共同作用时,能将激光器的腔面温度控制在393.15 K以下。550 K高温在激光器腔面处镀膜和隔热结构双重作用下,能够有效防止COD产生,提高激光器的使用寿命。     

大功率半导体激光器的腔面钝化

大功率半导体激光器的腔面退化是影响其寿命和可靠性的重要因素,长期以来一直是人们关注和研究的重点。本文利用离子铣结合腔面钝化还原层的方法对大功率半导体激光器的腔面进行处理。结果显示,离子铣腔面钝化能够在一定程度上减少半导体激光器的功率退化,168h加速老化后退化幅度降低4.5%;同时该技术对老化过程中COD阈值降低有明显的抑制作用,可有效减少使用中的突然失效。结果表明,该技术能够改善半导体激光器的腔面特性,器件的可靠性和使用寿命可望得到提高。     

半导体激光器中的光学灾变

介绍了用(NH4)2S和P2S5-NH4OH处理半导体激光器的表面来避免光学灾变的方法.重点介绍用氮离子注入形成窗口结构来避免光学灾变.     

808 nm掺铝半导体激光高损伤阈值腔面膜制备

研究了808 nm量子阱脊型波导结构掺铝半导体激光器在空气中解理不同镀膜方法对激光损伤阈值的影响.将半导体激光器管芯分别采用前后腔面不镀膜、前后腔面镀反射膜和前后腔面先镀钝化薄膜,再镀腔面反射膜的方法进行对比.测试半导体激光器输出功率的结果表明:腔面镀钝化薄膜的方法比只镀腔面反射膜的方法的激光损伤闽值高36%,并且能有效防止灾变性光学镜面损伤,同时,还分析了半导体激光器管芯和光学薄膜之间发生的物理效应.在大功率半导体激光器芯片腔面上镀钝化薄膜是提高其激光损伤阈值的一个行之有效的方法.     

大功率半导体激光器腔面氮钝化的研究

针对980 nm大功率半导体激光器腔面离子铣氮钝化处理工艺进行了研究,发现腔面离子铣氮钝化可以提高激光器的输出特性及COD功率,器件输出功率提高了32.14%;老化实验后,经过氮钝化的半导体激光器没有明显退化,而未经氮钝化处理的激光器退化严重;使用俄歇谱测试仪(AES)对钝化处理后的半导体激光器试验片进行测试,发现有部分的氮离子遗留在腔面处;氮元素含量由原有的0%上升到20%,与此同时,氧元素的含量由原来的61%降至30%。结果表明,该技术能够改善半导体激光器的腔面特性,器件的可靠性和使用寿命可望得到提高。     

808nm半导体激光器腔面硫钝化工艺研究

对808 nm大功率半导体激光器腔面硫钝化处理的工艺进行了研究,发现腔面硫钝化可以提高激光器的输出特性以及其可靠性,输出功率提高了16.7%;经过1 500 h老化实验后,硫钝化的半导体激光器没有明显退化,而未处理的激光器退化严重,输出功率降低了36.8%。实验表明,硫钝化时间对激光器钝化效果有很大影响,激光器腔面硫钝化时间过长会造成其损伤,使其可靠性反而下降;硫钝化5 m in效果为最佳。     

大功率半导体激光器腔面抗烧毁技术

首先介绍了连续激光器单管老化试验,试验通过测试不同老化时间激光器腔面的烧毁功率,对腔面烧毁发生的过程进行了分析。分析认为,大功率半导体激光器腔面烧毁失效的根本原因是腔面烧毁功率在老化过程中持续减小,最终低于激光器输出功率,造成激光器灾变性光学镜面破坏(COMD)。随后对腔面烧毁的微观物理机理进行了介绍,重点讨论了腔面缺陷相关的非辐射复合、量子阱带边吸收、自由载流子吸收造成的腔面温度升高以及腔面高温导致腔面缺陷密度增加并且向腔内攀移的微观过程。最后,介绍了电流非注入腔面、大光腔材料、长腔长设计、腔面离子铣钝化工艺等腔面抗烧毁技术研究情况,并对这些技术提高腔面抗烧毁功率以及改善腔面长期稳定性的效果进行了讨论。     

二维光子晶体对面发射激光器横模控制研究

垂直腔面发射激光器的单模输出特性在光网络数据传输光互连、光存储和激光打印中有重要的应用.传统的氧化限制型垂直腔面发射半导体激光器由于串联电阻大、发热严重而很难工作在单模状态.二维光子晶体结构可以有效地控制垂直腔面发射激光器的横向模式,使器件工作在单模状态下.从理论上系统研究了光子晶体垂直腔面发射半导体激光器的单模条件,成功设计了一组单模光子晶体垂直腔面发射半导体激光器,并通过常规工艺制作出功率0.6 mW、边模抑制比大于30 dB、阈值电流4 mA、远场发散角8.4°、不受电流注入影响的单模光子晶体垂直腔面发射半导体激光器.实验证明:光子晶体可有效地进行横模控制.     

Stability of sulfur-passivated facets of InGaAs-AlGaAs laser diodes

The facets of GaAs-AlGaAs ridge waveguide (RW) laser diodes were passivated using (NH/sub 4/)/sub 2/S/sub x/. The effectiveness of this procedure was checked by electroluminescence power-voltage-current (P-V-I) measurements that provide information on the changes in the density of surface states. Using this nondestructive method, the degradation of the passivation under ambient atmosphere has been studied. Capping with silicon nitride is found to stabilize the sulfur passivation and avoid degradation.     

Enhancement of output intensity limit of semiconductor lasers by chemical passivation of mirror facets

Reported is chemical treatment of the mirror facets of semiconductor lasers used to reduce nonradiative recombination centers, thereby enhancing their peak output power capabilities. Treatment of the surface with P/sub 2/S/sub 5/-NH/sub 4/OH coupled with washing by (NH/sub 4/)/sub 2/S can more than double the output intensity limit. However, the enhancement that can be obtained on a consistent basis is lower. It is expected that the chemically treated facet will remain passivated for times up to at least two months in air. However, to avoid photochemical processes during laser operation which could degrade the chemically passivated facet, it should be covered by an appropriate protective coating soon after the chemical treatment.<>     

对GaAs衬底表面进行氩离子清洗的研究

介绍了离子清洗技术在提高980nm半导体激光器可靠性方面的应用。外延片在空气中解理后，半导体激光器的腔面会吸附上碳和氧等杂质。腔面吸附的氧和碳严重影响了器件的可靠性。本文用GaAs衬底表面模拟半导体激光器的解理腔面，并对其进行氩离子清洗，俄歇电子能谱（AES）分析显示氩离子清洗可以有效地清除GaAS表面的氧和碳等杂质。     

Passivation of the facets of 980 nm GaAs pump lasers by a pulsed UV laser-assisted technique

It is reported on the passivation of the mirror facets, opened in the air, of ridge waveguide InGaAs/GaAs/AlGaAs single quantum well (λ=980 nm) laser diodes. The passivation concept consists of two steps, namely, oxide removal by irradiation of the mirror facets with a pulsed KrF laser, immediately followed by the deposition of a thin silicon layer. The experimental arrangement (the process operation and the aging behavior-resistance to catastrophic optical damage) of the lasers thus treated are described. The structural modification of the laser facets, as probed by micro-Raman spectroscopy and Rutherford backscattering spectroscopy, and the calibration technique used to assess the rate of oxide removal are also presented.     

Si (100) 表面 (NH4)2S 处理及其对Al/Si肖特基势垒的影响

The effect of Si （100） surface S passivation was investigated. A thick film with a high roughness value was formed on the Si surface treated by （NH4）2S solution, which was attributed to physical adsorption of S atoms. SEM and XPS analyses reveal that Si surface atoms were chemically bonded with S atoms after Si surface treatment in NH4OH and （NH4）2S mixing solution. This induces a more ideal value for the Schottky barrier height compared with a diode treated only by HF solution, indicating that surface states originating from dangling bonds are passivated with S atoms.     

Improvements in electrostatic discharge performance of InGaAsPsemiconductor lasers by facet passivation

Chemically treating laser facets with aqueous sulfides can significantly improve the electrostatic discharge (ESD) performance of InGaAsP semiconductor lasers. Commercial lasers free of internal defects were subjected to forward-biased Human Body Model ESD stress pulses. Devices passivated with sulfides exhibited a mean ESD failure voltage more than 400% higher than that of the untreated control group. Subsequent accelerated aging experiments suggest that a thick layer of oxide covering the laser facets, largely removed by the sulfide treatment, is responsible for the low ESD failure voltage on untreated devices. This suggests that sulfide passivation followed by facet encapsulation in a robust dielectric could result in permanent protection against ESD failure     

Novel passivation process for the mirror facets of Al-free active-region high-power semiconductor diode lasers

A novel process for the passivation of mirror facets of Al-free active-region high-power semiconductor diode lasers is presented. Designed for technological simplicity and minimum damage generated within the facet region, it combines laser bar cleaving in air with a two-step process consisting of 1) removal of thermodynamically unstable species and 2) facet sealing with a passivation layer. Impurity removal is achieved by irradiation with beams of atomic hydrogen, while zinc selenide is used as the passivating medium. The effectiveness of the process is demonstrated by operation of 808-nm GaAsP-active ridge-waveguide diode lasers at record optical powers of 500 mW for several thousand hours limited only by bulk degradation.     

SLA端面增透膜设计的理论分析与计算

文章推导了多层平板波导结构的半导体激光放大器 (SLA)端面反射率的计算方法 ,为优化设计SLA端面增透膜参数提供了工具。对InGaAs/InGaAlAs多量子阱SLA端面增透膜参数进行了优化设计 ,并给出优化结果。     

GaAs基半导体激光器真空解理钝化工艺研究

对GaAs基半导体激光器真空解理钝化工艺进行了研究,发现在高真空条件下解理和钝化GaAs基半导体激光器能有效减少激光器腔面缺陷,从而抑制非辐射复合。通过测试光致发光(PL)谱线和X射线光电子能谱(XPS)发现,经过超高真空解理钝化的GaAs基半导体激光器bar条的光致发光特性比没有经过真空解理钝化获得比较大的提升,并且bar条表面污染率有很大改观。对真空解理钝化工艺的钝化膜的厚度进行了优化。     

915 nm半导体激光器新型腔面钝化工艺

针对半导体激光器腔面光学灾变损伤的发生机制,设计了一种单管芯半导体激光器腔面真空解理钝化工艺方法。在真空中解理并且直接对半导体激光器腔面蒸镀钝化膜,提出用ZnSe材料作为单管芯半导体激光器真空解理工艺的钝化膜材料,发现利用真空解理钝化工艺方法和ZnSe材料作为钝化膜可以使器件输出功率提高23%。通过电致发光（EL）对半导体激光器腔面损伤机理进行分析。进一步说明对915 nm半导体激光器制备工艺中引入真空解理钝化工艺技术并且选择ZnSe作为钝化膜可以有效保护半导体激光器腔面,提高器件可靠性。