发射波长1.5μm的InGaAsP/InP分隔多包层条形激光器

本文报导了发射波长为1.5μm的InGaAsP/InP分隔多包层条形激光器。25℃下的CW阈值电流只有82mA,获得CW激射的最高温度为65℃。脉冲阈值电流的特征温度为60K。在CW工作条件下直到1.5倍阈值电流,基横模为基模,纵模为单模。在50℃,5mW/端面的恒定光功率条件下,有几只样品工作已超过1000小时。     

1.3μm波长倒置脊形波导激光器的特性

本文介绍了发射波长为1.3μm的倒置脊形波导激光器的制造和工作特性,在直至20mW的输出功率范围内实现了稳定的基横模CW工作。CW激射温度高达90℃。同时也给出了光谱测量和可靠性数据。     

V形槽衬底InGaAsP/InP BH激光器

<正> 日本富士通实验室研制了一种发射波长为1.3μm的BH激光器:V形槽衬底BH激光器(VSB)。在这种结构中,有源层埋在衬底上的V形槽内。为了制作这种激光器,研制出一种腐蚀方法,用这种方法在<011>方向上形成V形槽。25℃时CW阈值电流范围在10～20mA。一直到20mW/端面的光功率均可获得稳定的基横模激射。CW激射的最高温度为100℃。纵模是多模,然而其包络半最大点的全宽(FWHW)典型值低于3nm。动态特性呈现出     

发射波长为1.55μm范围的扩散条形InP/InGaAsP/InP激光器的特性

本文描述了发射波长约为1.55μm的InGaAsP/InP激光器的制造工艺和激射特性。采用低温液相外延方法制备的InP/InGaAsP/InP双异质结构外延片,制造了发射波长在1.53～1.60μm范围的锌扩散条形几何结构激光器。研究了激射特性与条宽的依赖关系。具有1.3μm条宽的激光器得到了最低的阈值电流(在27℃,CW工作条件下,约为160mA)。热沉温度高达53℃时获得了激光器的CW工作。在条宽足够窄(～6μm)的情况下,CW工作时得到了基横模和单纵模工作,而且激光器具有很好的高频性能。在高频(800Mbit/s)大信号脉冲调制情况下,激光器呈现出极好的动态特性。800Mbit/s时的纵模包络半最大点的全宽约为30(?)。     

氨的激光复相催化氧化反应和氮同位素的分离

本文以多晶铂-10%铑丝为催化剂,将CW CO_2激光束通过热丝圈使氨分子激发,研究了氨的激光复相催化氧化反应的动力学,在热丝温度为525——602K范围内,测得该反应的动力学方程式为v=k_LP_(NH3)·Po_2~(1/2),在激光辐照下的表观活化能为15Kcal/mole,比单纯热反应降低了10Kcal/mole。此外,曾以10.6μmR(40)支线的CW CO_2激光选择性激发~(15)NH_3,控制Pt-Rh丝在反应阈值温度(225℃)时,利用上述反应对~(15)NH_3和~(14)NH_3进行了同位素分离,并获得初步的分离效果。     

发射波长1.5～1.6μm的GaInAsP/InP隐埋异质结构分布布拉格反射器集成双波导激光器的低阈值电流CW工作

波长1.5～1.6μm的GaInAsP/InP隐埋异质结构分布布拉格反射器集成双波导(BH-DBR-ITG)激光器直到12℃均可获得低阈值电流CW工作。在25°温度范围内获得了单波长工作。激射波长与温度的关系为0.10nm/deg。在248K,阈值电流、微分量子效率和最大输出功率分别为37mA、16.3％/端面和6mW。     

1.5μm波长范围的InGaAsP/InP分布反馈式激光器

<正> 日本KDD研究和发展实验室从理论上和实验上研究了1.5μm波长范围的InGaAsP/InP分布反馈式(DFB)激光器的激射特性。分析了5层DFB波导中波的传播,估算出结构参数对阈值条件的影响。在设计低阈值激光器及其激射波长方面进行了主要考虑。用液相外延方法制备了具有1.53μm发射主光栅的DFB隐埋异质结构激光器。在-20℃～58℃的温度范围内实现了CW工作。室温下的CW阈值电流低至50mA。在直流与500Mbit/s的伪随机脉冲电流     

宽接触区InGaAlP可见光激光二极管的大功率CW工作

已制出具有防反射涂层和高反射涂层的宽接触区InGaAlP可见光激光二极管。在2℃热沉温度下可获得高于300mW的大功率CW工作。这个值相当于2.8mW/cm~2的光功率密度。输出功率高达100mW时,其远场图形呈现单波瓣形状。     

波长为1.3μm的V形槽激光器

本文描述的这种新型窄条扩散型GaInAsP/InP激光器不仅容易制作,而且在光输出功率大于35mW/端镜面、CW工作的条件下,显示出既稳定又无扭折的光电流特性。直到70℃还能实现CW工作。     

1.5μm平面掩埋脊形波导激光器的高温连续工作

<正> 据西德Siemens AG研究实验室报导,他们采用多次LPE方法制作了1.5μm GaInAsP/InPPBRS激光器。在没有电流阻挡层的情况下得到了有效的电流限制。25℃下CW阈值电流低至9mA。80℃下的输出功率达到10mW/端面,100℃下达到3.5mW。最高工作温度为110℃,它     

InGaAsP/InP separated multiclad layer stripe geometry lasers emitting at 1.5 ?m

InGaAsP/InP separated multiclad layer stripe geometry lasers emitting at 1.5 ?m are reported. The CW threshold current at 25°C is only 82 mA and the maximum temperature where CW lasing is obtained is 65°C. The characteristic temperature of the pulsed threshold current is 60 K. The transverse mode is fundamental and the longitudinal mode is single up to 1.5 times the threshold under CW operation. A few samples operated for over 1000 h at 50°C under constant optical power operation of 5 mW/facet.     

High temperature CW operation of 1.5 ?m InGaAsP/InP buffer-layer loaded planoconvex waveguide lasers

InGaAsP/InP buffer-layer loaded planoconvex waveguide lasers are reported. The CW threshold current at 20°C was 70 mA. The maximum CW operating temperature of 70°C was achieved. The characteristic temperature under CW operation was 51 K. Operation in fundamental transverse mode and single longitudinal mode up to 1.9 and 1.4 times the threshold current, respectively, was obtained.     

Thermally accelerated degradation of 1.3 ?m BH lasers

An investigation has been made into the thermally accelerated degradation in ACC lifetests for 1.3 ?m BH lasers. The CW threshold current under high-stress aging has been evaluated at various temperatures. An increase in the CW threshold current was observed which could be represented as a combination of two linear variations. It was found that the rapid increase of the CW threshold current was dependent on the evaluation temperature, which could be an important parameter in assessing the degradation of InGaAsP lasers.     

High performance CW 1.26 μm GaInNAsSb-SQW and 1.20 μmGaInAsSb-SQW ridge lasers

Long-wavelength GaInNAsSb SQW lasers and GaInAsSb SQW lasers that include small amounts of Sb have been successfully grown by gas-source molecular beam epitaxy (GSMBE) and processed into ridge lasers. The GaInNAsSb lasers oscillated under CW operation at 1.258 μm at room temperature. A low CW threshold current of 10.2 mA and high characteristic temperature (T₀) of 146 K were obtained for the GaInNAsSb lasers which is the best result for GaInNAs-based narrow-stripe lasers. Furthermore. The GaInAsSb lasers oscillated under CW operation at 1.20 μm at room temperature. A low CW threshold current of 6.3 mA and high characteristic temperature (T₀) of 756 K were obtained for the GaInAsSb lasers, which is also the best result for the 1.2 μm-range of highly strained GaInAs-based narrow-stripe lasers     

Low-threshold-current distributed-feedback InGaAsP/InP CW lasers

Distributed-feedback buried-heterostructure InGaAsP/InP lasers with room temperature CW threshold current as low as 50 mA, corresponding to a current density of 2.3 kA/cm2, are presented. CW operation in the temperature range from ?20°C to 58°C was confirmed.     

Continuous-wave operation of terahertz quantum-cascade lasers

We report continuous-wave (CW) operation of a 4.4-THz quantum-cascade laser grown in the GaAs-AlGaAs materials system by molecular beam epitaxy. The device operates at 4 K with a threshold current of 160 mA, and an output power of /spl sim/25 /spl mu/W. In pulsed mode, the maximum operating temperature is 52 K, with a threshold current of 108 mA at 4 K. CW lasing was achieved by using a small cavity ridge area (60/spl times/600 /spl mu/m), and by coating one of the laser facets. These two features allowed for a substantial decrease of the threshold current and therefore reduced detrimental heating effects. The role played by the lateral resistance of the 800-nm GaAs layer underneath the active region was also investigated. Experimental data is presented showing that the temperature of the active region, which eventually hinders CW lasing, can be substantially influenced by the value of this lateral resistance.     

Room-temperature continuous-wave operation of GaInNAsSb laser diodes at 1.55 /spl mu/m

The first 1.55 /spl mu/m room-temperature continuous-wave (CW) operation of GaAs-based laser diodes utilising GaInNAsSb/GaNAs double quantum well active regions grown by molecular beam epitaxy is reported. In electrically-pumped CW operation the narrow ridge waveguide devices have a room temperature lasing wavelength of 1550 nm near threshold, increasing to 1553 nm at thermal rollover. The CW threshold current was 132 mA for a 3/spl times/589 /spl mu/m device, with a characteristic temperature of 83 K, measured in pulsed mode between 20 and 70/spl deg/C.     

1.5 µm range InGaAsP/InP distributed feedback lasers

Lasing characteristics of InGaAsP/InP distributed feedback (DFB) lasers in the 1.5 μm range were studied theoretically and experimentally. Wave propagation in five-layer DFB waveguides were analyzed to estimate the effect of the structural parameters on threshold conditions. A brief consideration on designing a low threshold laser and its lasing wavelength was made. DFB buried heterostructure lasers with fundamental grating emitting at 1.53 μm were prepared by liquid phase epitaxial techniques. CW operation was confirmed in the temperature rangeof -20° to 58°C, and a CW threshold current was as low as 50 mA at room temperature. A stable single longitudinal mode operation was observed both in dc condition and in modulated condition by a pseudorandom pulse current at 500 Mbits/s. No significant increase in the threshold current was observed after 1400 h continuous CW operation at 20°C.     

Large CW power, very-low-threshold, single transverse modeoperation of vertical cavity mushroom structure surface emitting lasers

Summary form only given. Continuous-wave GaAs mushroom structure surface emitting laser (MSEL) operation at a threshold current as low as 1.6 mA, an output power >2.0 mW, and a single transverse mode up to three times threshold current is reported. The relatively large CW output power was achieved by reducing the series resistance using a selective zinc diffusion. The low threshold current and single-mode operation are attributed to good lateral current confinement in a small constricted region formed by mesa undercutting. The complete device was mounted junction-side up on a chip carrier and tested CW at room temperature. Some results are given     

Cryogenic VCSELs with chirped multiple quantum wells for a very wide temperature range of CW operation

Cryogenic optical data links require an efficient optical source with temperature-insensitive continuous-wave (CW) operation at low temperatures. Also, to simplify optical alignment, it is desirable to obtain CW operation over a broad temperature range that spans both the low and high temperatures. By the use of vertical-cavity surface-emitting lasers (VCSELs) with chirped (nonuniform) multiple quantum wells (MQWs) to broaden the optical gain spectrum, CW operation has been achieved from 5-350 K, with improved characteristics in both the high- and low-temperature regimes. In particular, temperature-insensitive, submilliampere threshold current was achieved at temperatures from 5-50 K, with a threshold current density of 350 A/cm/sup 2/, and a threshold voltage that is below 3 V.