表面光栅垂直腔面发射激光器偏振特性研究

研究了表面光栅结构对垂直腔面发射激光器(VCSEL)的偏振控制作用。引入表面光栅后,对不同刻蚀深度下的偏振相关的镜面损耗进行了仿真,结果表明表面光栅刻蚀深度在44~130 nm范围内均可实现稳定偏振,具有较大的工艺容差。表面光栅VCSEL在基横模工作状态下偏振抑制比(Orthogonal Polarization Suppression Ratio, OPSR)超过20 dB,偏振光谱峰间偏振抑制比达到40 dB,且在多横模状态也实现了有效的偏振控制。为了进一步验证光栅对偏振控制的效果,制作了方向互相垂直的两种表面光栅,具有这两种方向光栅的VCSEL的OPSR均达20 dB以上。测试分析表明表面光栅是VCSEL实现稳定偏振的一种有效手段。     

Tunable doped-fibre vertical cavity surface emitting laser

A simple way to improve the output power of singlemode tunable VCSELs is demonstrated. It is based on a master oscillator power amplifier (MOPA)-like embodiment of a fibre-VCSEL. The reported device, operating at 1.55 μm, uses a single pump source to photoexcite both a semiconductor structure and a doped fibre without compromise in compactness. Initial results show continuous tunability over 11 nm and fibre-coupled output power of 3.1 mW. It is noted that this approach can be extended to any part of the spectrum for which rare-earth doped optical fibres are available.     

Micro-fluidic photonic crystal vertical cavity surface emitting laser

The first monolithic micro-fluidic photonic crystal vertical cavity surface emitting laser (VCSEL), wherein the horizontal and vertical micro-fluidic channels lie within the VCSEL, is reported. The micro-fluidic photonic crystal VCSEL is created with two principal steps after fabrication of the VCSEL. The first step is integrating the two-dimensional photonic crystal with the VCSEL structure. The photonic crystal creates singlemode operation, and acts as the vertical micro-channels. After creating the photonic crystal pattern in the VCSEL, the oxide layer is selectively wet etched to form the horizontal channel. Preliminary results obtained from the introduction of fluid into the micro-channels are presented.     

Spin controlled optically pumped vertical cavity surface emitting laser

It is shown that the output polarisation of optically pumped vertical cavity surface emitting lasers (VCSELs) can be unambiguously controlled by the pump polarisation. The degree of the output polarisation is higher than that of the pump polarisation. It is concluded that the polarisation of VCSELs with spin polarised electrical pumping can be controlled even with low spin injection efficiencies.     

High-power vertical cavity surface emitting laser with good performances

Fabrication and performance of a high-power bottom-emitting InGaAs/GaAsP vertical cavity surface emitting laser with 430 /spl mu/m diameter are described. The device realises the maximum room temperature CW output power 1.52 W at 987.6 nm with FWHM 0.8 nm. The far-field divergence angle is below 20/spl deg/. Reliability test shows at 70/spl deg/C an output power 0.35 W over 500 h.     

Passively modelocked vertical extended cavity surface emitting diode laser

Passive modelocking of a surface emitting diode laser is demonstrated using an extended cavity concept which permits the incorporation of a saturable Bragg reflector mirror into a device designed for large aperture operation as a high-power 980 nm InGaAs multiple quantum-well vertical cavity source.     

Blue-green optically pumped GaN-based vertical cavity surface emitting laser

Blue-green GaN-based vertical cavity surface emitting lasers (VCSELs) were fabricated with two dielectric Ta₂O₅/ SiO₂ distributed Bragg reflectors. Lasing action was observed at a wavelength of 498.8 nm at room temperature under optical pumping. Threshold energy density and emission linewidth were 189 mJ/cm² and 0.15 nm, respectively. The result demonstrates that blue-green VCSELs can be realised using III-nitride semiconductors.     

Multiple-input optical control of vertical cavity surface emitting lasers using intracavity-coupled in-plane lasers

We report new experimental results demonstrating optical bistability and two-input NOR gate operation in intracavity-coupled in-plane and vertical cavity surface emitting lasers (VCSELs) fabricated from the same epitaxial material. The VCSEL (or output) section gain is controlled by separately biased in-plane laser section(s), and depending on the in-plane power output, complete quenching of stimulated emission in the VCSEL is observed. Hysteresis is present in the VCSEL output power versus in-plane laser input power characteristic, and an optical memory effect is observed in the combined device.     

Monolithic integration of photodetector with vertical cavity surface emitting laser

For the first time, monolithic integration of a photodetector with a vertical-cavity surface emitting laser (VCSEL) is demonstrated. The authors have designed and fabricated VCSELs with monolithically integrated pin photodetectors which dynamically monitor (and can thus control) the output power of the lasers. The VCSELs lase at room temperature and emit a highly coherent, low-divergence, circular beam directly from the top surface. The integrated photodetector shows a linear response to the laser emission with an effective responsivity of 0.25 A/W.<>     

质子注入型光子晶体垂直腔面发射激光器制备

在光子晶体垂直腔面发射激光器中采用质子注入工艺,使台面工艺变成纯平面工艺,降低了光子晶体结构制备难度,简化了器件制备,提高了器件的均匀性。质子注入型光子晶体垂直腔面发射激光器中的光子晶体结构,在电流限制孔小于光子晶体缺陷孔时,仍能控制器件光束及模式特性,该结果可用于优化器件阈值电流,制备高性能低阈值电流基横模器件。实验所设计制备的器件,在注入电流小于12.5 mA时,阈值电流2.1 mA,出光功率大于1 mW,远场发射角小于7,有效验证了光子晶体结构在质子注入型面发射激光器中的光束改善及模式控制作用。     

High-power surface emitting semiconductor laser with extended vertical compound cavity

Novel, electrically pumped, vertical compound cavity InGaAs lasers emitting at 980 nm are described. These have generated 1 W continuous-wave multimode and 0.5 W continuous-wave in a fundamental TEM/sub 00/ mode and single frequency, with 90% coupling efficiency into a singlemode fibre.     

可调谐垂直腔面发射激光器

近年来国内外在可调谐垂直腔面发射激光器这一研究领域取得了极大的进步。叙述了可调谐垂直腔面发射激光器的结构原理和发展历程,对不同结构的优缺点作了对比介绍,展望了可调谐激光器的发展前景。这种器件在光传输、光互连及光并行信息处理等方面有着良好的应用前景。     

Temperature characteristics of InGaAs/GaAs vertical cavity surface emitting laser

The temperature characteristics for the different lasing modes at 300 K of intracavity contacted InGaAs/GaAs Vertical Cavity Surface Emitting Lasers（VCSELs） have been investigated experimentally by using the SV-32 cryostat and LD200205 test system. In combination with the simulation results of the reflective spectrum and the gain peak at different temperatures, the measurement results have been analyzed. In addition, the dependence of device size on temperature characteristics is discussed. The experimental data can be used to optimally design of VCSEL at high or cryogenic temperature.     

新型正方晶格基横模光子晶体面发射激光器

高功率基横模垂直腔面发射激光器（VCSEL）在光通信、传感、原子频标和光电混合集成等领域有着重要的应用,将光子晶体结构引入到VCSEL中,通过设计结构尺寸和分布,可以有效控制VCSEL的横向模式。课题组将正方形排列的光子晶体结构引入到VCSEL中,实现对VCSEL的横向模式和基横模出光功率控制,获得高基横模出光功率器件。通过采用平面波展开法（PWE）和全矢量三维时域有限差分方法（FDTD）对正方晶格结构光子晶体的合理设计,获得正方形排布光子晶体周期、占空比和刻蚀深度等重要参数。成功地制备出基横模出光功率大于3 mW,边模抑制比大于40 dB的正方晶格光子晶体VCSEL。     

垂直外腔面发射半导体激光器的热管理方法研究

垂直外腔面发射半导体激光器在高功率运转的同时可以保持良好的光束质量,近年来一直成为研究的热点。本文介绍了垂直外腔面发射半导体激光器的结构及运行原理。由于热管理是其高功率运行的主要限制因素之一,分析了垂直外腔面发射半导体激光器的热管理方法。使用反向生长的外延片通过化学湿法腐蚀去掉砷化镓衬底,得到了约6μm左右的外延片,最后利用808nm的泵浦光进行抽运获得了200mW的连续激光输出。     

Integrated optoelectronic probe including a vertical cavity surface emitting laser for laser Doppler perfusion monitoring

An integrated optoelectronic probe with small dimensions, for direct-contact laser Doppler blood flow monitoring has been realized. A vertical cavity surface emitting laser (VCSEL), and a chip with photodetectors and all necessary electronics are integrated in a miniature probe head connected to a laptop computer. The computer sound processor is utilized for acquisition and digital signal processing of the incoming Doppler signal. In this paper, the design of the laser Doppler perfusion monitor is described and its performance is evaluated. We demonstrate our perfusion monitor to be less sensitive to subject motion than a commercial fiber-optic device. For medium and high perfusion levels, the performance of our integrated probe is comparable to the fiberoptic flowmeter containing a normal edge-emitting laser diode. For very low perfusion levels, the signal-to-noise ratio of the fiber-optic device is higher. This difference can mainly be attributed to the shorter coherence length of the VCSEL compared with the edge-emitting laser diode.     

长波长垂直腔面发射激光器

给出了长波长垂直腔面发射激光器的器件结构的发展现状，同时对GaInNAs／GaAs垂直腔面发射激光器进行了详细的介绍。最后，给出了所设计的新型1.3μm GaInNAs/GaAs长波长垂直外腔面发射半导体激光器的结构设计，有源区量子阱由980nm半导体激光二极管进行泵浦。这种器件设计实现了激光二极管泵浦与长波长垂直腔面发射激光器的有机结合，同时具有两者的优点。此外，本文还对器件的阈值特性和光输出功率进行了理论计算。     

垂直腔表面发射激光器的研究

垂直腔表面发射激光器(VCSEL)是一种应用于光纤通信系统的低成本、高性能的特定波长光源,它具有测试简单、易耦舍以及易形成阵列等独特优势,已在光并行互连及高密度光存贮等领域得到大规模应用.文章介绍了VCSEL的结构和当前的制造工艺水平,阐述了各波段VCSEL的发展和应用现状,探讨了VCSEL在不同领域中的应用范围并指出了VCSEL的发展前景.     

Variable reflectance vertical cavity surface emitting lasers

Singlemode operation in 850 nm vertical cavity surface emitting lasers is reported. The singlemode behaviour results from a radially-varying number of periods in the top distributed Bragg reflector mirror. At the centre of the device there are six additional quarter-wave layers (three periods) as compared to the edge. This provides higher mirror reflectivity to the fundamental mode without adding loss. Thus the top mirror geometry promotes singlemode operation of the laser from threshold to rollover     

Microchip vertical external cavity surface emitting lasers

Monolithic vertical external cavity surface emitting lasers of cavity mode volume <1 mm/sup 3/ have been fabricated in the 850 and 980 nm wavelength range. Pump-limited output power >350 mW in a TEM/sub 00/ mode was obtained at 850 nm. Output power >2.5 W was obtained at 980 nm.