一种提高垂直腔面发射激光器性能的新工艺

采用一种新的工艺方法提高了垂直腔面发射激光器的输出功率.采用开环分布孔代替环形沟槽,使器件的输出功率提高了0.34倍.14μm孔径的器件输出功率超过10mW,工作电流为29.6mA时,最大输出功率达到12.48mW.而且,这些开环分布孔为电注入提供了便捷的桥通道,很好地解决了电极易过沟断线问题.器件表现了良好的高温工作特性,当温度高达60℃时输出功率仍可达到8mW.     

A New Process for Improving Performance of VCSELs

采用一种新的工艺方法提高了垂直腔面发射激光器的输出功率.采用开环分布孔代替环形沟槽,使器件的输出功率提高了0.34倍.14μm孔径的器件输出功率超过10mW,工作电流为29.6mA时,最大输出功率达到12.48mW.而且,这些开环分布孔为电注入提供了便捷的桥通道,很好地解决了电极易过沟断线问题.器件表现了良好的高温工作特性,当温度高达60℃时输出功率仍可达到8mW.     

新型结构垂直腔面发射激光器的研制

为改善垂直腔面发射半导体激光器(VCSEL)的热特性.提高其光电性能,研制了新型辐射桥结构的VCSEL,即采用辐射桥状的电流注入通道取代以往传统结构VCSEL的环形电流注入通道.研究表明辐射桥结构可以降低VCSEL器件的体电阻和热阻,改善器件的模式特性.在同一外延片上,采用相同的工艺制备了辐射桥结构与传统结构两种VCSEL器件,并对两种器件的光电性能进行了对比测试.结果表明,辐射桥结构VCSEL比传统结构的VCSEL微分电阻降低25%,输出功率提高到1.6倍;辐射桥结构的VCSEL具有良好的温度特性与模式特性,80℃时仍能正常激射,60℃时最大输出功率可达17 mW,器件的热阻可达1.95℃/mW;器件单模工作,其总体性能远优于传统结构的VCSEL器件.     

新型辐射桥结构VCSEL的设计、制作和热特性分析

为了改善垂直腔面发射半导体激光器(VCSEL)的热特性,提高器件的输出功率,设计并制作了一种新型辐射桥结构VCSEL。利用有限元热分析软件ANSYS,模拟了常规结构和辐射桥结构VCSEL内部的热场分布和热矢量分布。经模拟得到,常规结构器件的热阻为4.13K/W,辐射桥结构的热阻为2.64K/W。而经实验测得,常规结构器件的热阻为4.40K/W,辐射桥结构器件的热阻为2.93K/W,实验测试结果与模拟结果吻合较好。同时测得,常规结构器件的最大输出功率为305mW,辐射桥结构器件的最大输出功率为430mW,后者的输出功率提高了40%。     

1.3μm波段单横模大功率输出量子点激光器

为了制备大功率、单横模输出的量子点激光器,对有源多模干涉波导结构进行了研究。通过优化器件结构设计,采用1×1型有源多模干涉波导结构,以均匀多层InAs/InGaAs/GaAs量子点材料作为有源区,制备了1.3μm波段的有源多模干涉结构量子点激光器。连续电流注入条件下的测试结果表明,与传统的均匀波导结构器件相比,有源多模干涉结构器件具有更低的串联电阻和更好的散热性能;在连续电流为0.5A的小注入情况下,器件的输出功率可达114mW、中心波长为1332nm。结果表明,有源多模干涉结构器件是制备大功率、单横模输出光发射器件的一种有效的器件结构。     

1.3μm波段单横模大功率输出量子点激光器

为了制备大功率、单横模输出的量子点激光器,对有源多模干涉波导结构进行了研究。通过优化器件结构设计,采用1×1型有源多模干涉波导结构,以均匀多层InAs/InGaAs/GaAs量子点材料作为有源区,制备了1.3μm波段的有源多模干涉结构量子点激光器。连续电流注入条件下的测试结果表明,与传统的均匀波导结构器件相比,有源多模干涉结构器件具有更低的串联电阻和更好的散热性能;在连续电流为0.5A的小注入情况下,器件的输出功率可达114mW、中心波长为1332nm。结果表明,有源多模干涉结构器件是制备大功率、单横模输出光发射器件的一种有效的器件结构。     

新型垂直腔面发射激光器的研制北大核心CSCD

热问题是制约垂直腔面发射半导体激光器(VCSEL)的关键难题之一。为改善垂直腔面发射激光器的热特性,提高输出功率,设计并制备了一种新型内腔接触式结构VCSEL。在出光孔径为16μm时,同时制备传统结构和新型结构两种器件并对其进行测试,传统结构VCSEL的阈值电流为11.5 mA,当注入电流为34 mA时,最大输出功率达到7.3 mW;新结构器件的阈值电流为9 mA,当注入电流为35 mA时,最大输出功率达到10.2 mW;新结构的阈值电流降低了21.7%,最大输出功率提高了28%。结果表明,这种内腔接触式电极结构有望改善器件的热特性和光电性能。     

新型垂直腔面发射激光器的研制

热问题是制约垂直腔面发射半导体激光器(VCSEL)的关键难题之一。为改善垂直腔面发射激光器的热特性,提高输出功率,设计并制备了一种新型内腔接触式结构VCSEL。在出光孔径为16μm时,同时制备传统结构和新型结构两种器件并对其进行测试,传统结构VCSEL的阈值电流为11.5 mA,当注入电流为34 mA时,最大输出功率达到7.3 mW;新结构器件的阈值电流为9 mA,当注入电流为35 mA时,最大输出功率达到10.2 mW;新结构的阈值电流降低了21.7%,最大输出功率提高了28%。结果表明,这种内腔接触式电极结构有望改善器件的热特性和光电性能。     

大功率宽条分布反馈激光器研究

大功率半导体激光器一般用作抽运源,但其抽运的离子吸收峰带宽一般都比较小。为提高大功率半导体激光器对固体或光纤激光器等的抽运效率,就要降低半导体激光器的输出波长随注入电流和热沉温度的漂移系数。分析了光栅深度和光栅填充因子对激光器输出波长锁定效果的影响,实验验证确定出合适的光栅参数,依据优化条件得出合适的激光器腔长,制备出锁定效果良好的宽条分布反馈激光器。该激光器的单管腔长2.4mm,发光条宽100μm,连续最大输出功率400mW,热沉温度为15℃时的输出波长为954nm,输出波长随注入电流的漂移系数为0.67nm/A,输出波长的温漂系数为0.046nm/K。     

1120nm窄线宽掺镱光纤激光器

为了获得窄线宽、高功率、长波长(相对于1030nm~1080nm)的1120nm光纤激光器,采用普通单模掺镱光纤和一对光纤布喇格光栅构建了该光纤激光器的谐振腔,为保证抽运光的完全吸收和避免非线性效应,对有源光纤的最佳长度进行了理论分析和实验验证。结果表明,激光器的阈值抽运功率为40mW、注入抽运功率为265mW时,激光器输出信号光功率35mW,光光转换效率为13.2%,激光器中心波长为1120.9nm,输出激光的谱线宽度为0.03nm。这种激光器的获得是因为采用了高反射率耦合输出光纤布喇格光栅、短谐振腔结构和低功率运转状态。该激光器可作为种子光注入光纤放大器。     

MOVPE-grown GaInNAs VCSELs at 1.3 /spl mu/m with conventional mirror design approach

1.3 /spl mu/m oxide confined GaInNAs VCSELs designed using the same design philosophy used for standard 850 nm VCSELs is presented. The VCSELs have doped mirrors, with graded and highly doped interfaces, and are fabricated using production-friendly procedures. Multimode VCSELs (11 /spl mu/m oxide aperture) with an emission wavelength of 1287 nm have a threshold current of 3 mA and produce 1 mW of output power at 20/spl deg/C. The maximum operating temperature is 95/spl deg/C. Emission at 1303 nm with 1 mW of output power and a threshold current of 7 mA has been observed from VCSELs with a larger detuning between the gain peak and the cavity resonance.     

A new process to improve the performance of 850 nm wavelength GaAs VCSELs

In this article, we propose a new process method to improve the light output power of GaAs vertical-cavity surface-emitting lasers (VCSELs). The VCSELs with filling Al metal into the ring trench will exhibit a higher quantum efficiency and have a light output power of 1.45 times higher than those without filling Al. In addition, the trench filled with Al metal can benefit in the bonding process and behavior as a mirror to reduce the output power loss. These VCSELs show good output characteristics and high-temperature operation.     

1.3-/spl mu/m Vertical-cavity surface-emitting lasers with double-bonded GaAs-AlAs Bragg mirrors

We demonstrate, for the first time, double-bonded AlGaInAs strain-compensated quantum-well 1.3-/spl mu/m vertical-cavity surface-emitting lasers (VCSELs). GaAs-AlAs Bragg mirrors were wafer-bonded on both sides of a cavity containing the AlGaInAs strain-compensated multiple-quantum-well active layers sandwiched by two InP layers. The lasers have operated under pulsed conditions at room temperature. A record low pulsed threshold current density of 4.2 kA/cm/sup 2/ and a highest maximum light output power greater than 4.6 mW have been achieved. The maximum threshold current characteristic temperature T/sub 0/ of 132 K is the best for any long wavelength VCSELs. The laser operated in a single-longitudinal mode, with a side-mode suppression ratio of more than 40 dB, which is the best results for 1.3-/spl mu/m VCSELs.     

650-nm vertical-cavity surface-emitting lasers: laser properties and reliability investigations

650-nm AlGaInP-AlGaAs-based oxide-confined VCSELs are investigated in dependence on the current aperture size. VCSELs with small aperture (a=5 /spl mu/m) have a maximum continuous-wave (CW) output power of about 1 mW at room temperature. They reach higher operating temperatures (T/sub max/=55/spl deg/C), have narrower beam profiles, less transverse modes, and a higher side mode suppression compared to large aperture VCSELs (a>13 /spl mu/m). The latter devices emit a CW-output power P=3 mW at 20/spl deg/C. Reliability tests of 655-nm devices show at 20/spl deg/C an output power of P/spl ap/0.4 mW over more than 1000 h and at 40/spl deg/C P/spl ap/0.1 mW over 500 h.     

Room temperature continuous-wave operation of GaInNAs/GaAs VCSELsgrown by chemical beam epitaxy with output power exceeding 1 mW

The authors present a near 1200 nm wavelength vertical-cavity surface-emitting laser (VCSEL) the active region of which is formed by GaInNAs/GaAs quantum wells grown by chemical beam epitaxy. Room temperature continuous-wave operation has been demonstrated with a high slope efficiency of 0.23 W/A, a high output power of over 1.0 mW, and a singlemode output power of 0.34 mW. The fabricated devices with different aperture sizes show low threshold currents of 1.2-2.1 mA and a record low threshold current density of 2.6 kA/cm² in GaInNAs VCSELs     

High-performance 1.3 /spl mu/m InGaAs vertical cavity surface emitting lasers

A report is presented on high-performance InGaAs/GaAs double quantum well vertical cavity surface emitting lasers (VCSELs) with record long emission wavelengths up to 1300 nm. Due to a large gain-cavity detuning these VCSELs show excellent temperature performance with very stable threshold current and output power characteristics. For 1.27 /spl mu/m singlemode devices the threshold current is found to decrease from 2 to 1 mA between 10 and 90/spl deg/C, while the peak output power only drops from 1 to 0.6 mW. Large-area 1300 nm VCSELs show multimode output power close to 3 mW.     

1.3 /spl mu/m InGaAsN vertical cavity surface emitting lasers grown by MOCVD

The first InGaAsN VCSELs grown by MOCVD with CW lasing wavelength longer than 1.3 /spl mu/m are reported. The devices were of conventional p-i-n structure with doped DBR mirrors. CW lasing up to 65/spl deg/C was observed, with a maximum output power at room temperature of 0.8 mW for multimode devices and nearly 0.3 mW for single-mode devices.     

GaAs/AlGaAs multiple quantum well GRIN-SCH vertical cavity surfaceemitting laser diodes

Vertical cavity surface emitting lasers (VCSELs) with GaAs/AlGaAs multiple quantum well (20 wells) graded-index separate-confinement-heterostructure (GRIN-SCH) active regions are discussed. The VCSEL structures, which also contained two Al_xGa_1-xAs/Al_yGa_1-yAs distributed Bragg reflectors, were grown by molecular beam epitaxy and had a threshold current and current density at room temperature pulsed excitation of 16 mA and 14 kA/cm², respectively, near 0.85-μm wavelength. Both single-longitudinal and fundamental transverse mode emission characteristics were observed with a light output greater than 3 mW and a slope efficiency of 0.12 mW/mA     

Cavity Mode—Gain Peak Tradeoff for 1320-nm Wafer-Fused VCSELs With 3-mW Single-Mode Emission Power and 10-Gb/s Modulation Speed Up to 70 °C

Room-temperature cavity mode red-shift of about 45nm from the photoluminescence peak is found to be optimal for tradeoff between high modulation bandwidth and good high-temperature performance for InAlGaAs(InP)-AlGaAs fused vertical-cavity surface-emitting lasers (VCSELs) employing tunnel junction carrier injection. Single-mode output power up to 5.4 and 3.1 mW, at 25 degC and 75 degC, respectively, and open eye diagrams exhibiting fall time values close to 40 ps at 10-Gb/s modulation up to at least 70 degC have been obtained for such VCSELs emitting at 1320-nm wavelength