Long-wavelength (l ?1.55 lm) monolithic VCSEL array with > 3W CW output power

Monolithically integrated long-wavelength vertical-cavity surface- emitting high-power laser arrays emit continuous wave (CW) optical output power in excess of 3 W at 1.55 mum. Regardless of the wavelength, this is the highest CW output power reported from a monolithic VCSEL structure to date.     

Long-wavelength monolithic GaInNAs vertical-cavity optical amplifiers

We report on the continuous-wave amplification characteristics of an optically pumped 1.3-/spl mu/m multiple-quantum-well GaInNAs-GaAs vertical-cavity semiconductor optical amplifier (VCSOA). The VCSOA structure was monolithically grown by molecular beam epitaxy and operated in reflection mode in a fiber-coupled system. The maximum on-chip gain attained, limited by the onset of laser action, was 15.6 dB at 196 mW of 980-nm pump power. For a chip gain of 10.4 dB, the optical bandwidth was 10.8 GHz and the saturation output power was -9 dBm. By varying the pump laser power, a maximum extinction ratio of 22.3 dB was obtained. Temperature-controlled tuneable operation of the device is also presented and demonstration of 9 dB of chip gain obtained over 9.5 nm with an optical bandwidth of 12 GHz is reported.     

Ultra-high-power quasi-CW monolithic laser diode arrays with high power conversion efficiency

An optical power output of 134 W from one facet and power conversion efficiencies as high as 49% have been obtained from monolithic AlGaAs laser arrays with 1 cm emitting widths for 150^s pulse widths (quasi-CW operation). The arrays have etched grooves to prevent transverse lasing and amplified spontaneous emission.     

Quasi-planar monolithic integration of high-speed VCSEL andresonant enhanced photodetector arrays

We describe the quasi-planar monolithic integration of oxide-confined vertical-cavity surface-emitting laser (VCSEL) and resonant enhanced photodetector (REPD) arrays. These high speed devices are fabricated using an approach in which current apertures with a range of different sizes are formed by concatenating a number of discrete crescent shaped oxidation fronts. This approach preserves planarity while improving dimensional control for devices with very small oxide apertures (<4 μm). It resulted in VCSEL's with electrical and optical characteristics that are comparable to those of etched-mesa devices, while producing high-speed REPD's with a rise time of ~65 ps     

长波长VCSEL结构中的欧姆接触工艺

简要叙述了欧姆接触工艺在长波长垂直腔面发射激光器(VCSEL)制作中的重要作用.采用圆环传输线方法(CTLM)研究了应用于长波长VCSEL结构的p型InGaAsP和InP材料与Ti-Au的接触特性,发现p-InGaAsP与Ti-Au经高温退火后能获得欧姆接触,其最低比接触电阻值可达6.49×10-5Ω·cm2.将此工艺结果应用于1.3 μm VCSEL结构中,发现其开启电压和串联电阻显著减小.     

Multimode WDM optical data links with monolithically integratedmultiple-channel VCSEL and photodetector arrays

We report on the design and implementation of a novel multiple-wavelength optical data link for low-cost multimode wavelength-division multiplexing (WDM) local-area network applications. This link utilizes a monolithically integrated multiple-wavelength vertical-cavity laser array and a narrow-band resonant-cavity photodetector array to transmit multiple channels of information simultaneously via a single multimode fiber. A detailed analysis on wavelength tuning and threshold characteristics of different laser cavity designs is presented. Theoretical results are compared to our experimental data. On the receiver part, both Schottky and p-i-n photodetectors with a single- or coupled-cavity structure are discussed. A novel p-i-n resonant-cavity photodetector design with a partially oxidized front mirror for linewidth control is proposed. Moreover, we also demonstrate preliminary measurements on the optical link built with our multiple-wavelength vertical-cavity laser array and photodetector array. Finally, the feasibility of constructing a multiwavelength optical data link with a single dual-core multimode fiber and an integrated laser/detector array is evaluated     

Monolithic wavelength-graded VCSEL and resonance-enhancedphotodetector arrays for parallel optical interconnects

Monolithic arrays of wavelength-graded vertical-cavity surface-emitting lasers (VCSELs) and resonance-enhanced photodetectors (PDs) have been realized with the same epilayer structure using the topography-controlled enhancement and reduction of the metal-organic chemical vapor deposition (MOCVD) growth rate on a patterned substrate. The repeatability of this technique was demonstrated by using different VCSEL and resonance-enhanced photodetector (REPD) arrays from the same wafer     

大功率垂直腔面发射激光器技术研究

大功率垂直腔面发射激光与目前比较成熟的边发射激光相比在光束质量、二维面阵集成、高温工作等方面有很强的优势.2008年以来国内外研究进展迅速,在激光输出功率、效率、波长的多样性以及在应用探索等方面都有长足进步.从垂直腔面发射激光结构特征出发,对其优点特性、国外进展情况,在激光引信等需要窄脉冲工作场合的应用研究情况进行了介...     

Wavelength accuracy and output power of multiwavelength DFB laser arrays with integrated star couplers and optical amplifiers

In this letter, we report the static performance of multiwavelength DFB laser arrays with integrated star couplers and optical amplifiers built for the reconfigurable optical network testbed. By the use of wavelength redundancy and proximity effect, wavelength deviations of /spl plusmn/0.2 nm or less from the designated eight-wavelength comb have been achieved with high yield. Simultaneous operation of eight wavelengths has also been demonstrated. In spite of the inherent splitting loss of 13 dB, high output powers of about -13 dBm and 0 dBm per wavelength have been measured into a single-mode fiber without and with on-chip optical amplification, respectively.     

高输出功率正弦信号发生器

基于直接数字频率合成DDFS(Direct Digital Frequency Synthesize)技术,依据调制信号相关原理,设计以DDS集成电路AD9851为核心的正弦信号发生器,可精确输出幅度调节范围为50 mVpp～20 Vpp,频率调节范围100 Hz-30 MHz的正弦波,还可输出调幅波、调频波、PSK、ASK信号.该设计在宽频带内能获得大幅度的低失真波形.采用多种抗干扰措施以减少噪声并抑制高频自激,通过软件补偿提高频带内输出幅度的平坦度.该系统输出波形谐波失真度小,无杂散动态范围(SFDR)达39.8 dBc,功能稳定,操作简便.     

高输出功率正弦信号发生器

基于直接数字频率合成DDFS（Direct Digital Frequency Synthesize）技术,依据调制信号相关原理,设计以DDS集成电路AD9851为核心的正弦信号发生器,可精确输出幅度调节范围为50mVPP-20VPP,频率调节范围100Hz-30MHz的正弦波。还可输出调幅波、调频波、PSK、ASK信号。该设计在宽频带内能获得大幅度的低失真波形。采用多种抗干扰措施以减少噪声并抑制高频自激,通过软件补偿提高频带内输出幅度的平坦度。该系统输出波形谐波失真度小,无杂散动态范围（SFDR）39．8dBc,功能稳定,操作简便。     

Two-dimensional electronic beam-steering with implant-defined coherent VCSEL arrays

Evanescently-coupled two-dimensional vertical cavity surface emitting laser arrays may be defined by proton implantation in the top mirror. By controlling injection current to each of the elements in these laser arrays, the main lobe of emission can be steered in different directions up to 5deg from normal. This two-dimensional electronic beam-steering with a three-element triangular array is demonstrated.     

A broad-band MQW semiconductor optical amplifier with high saturation output power and low noise figure

A broad-band semiconductor optical amplifier (SOA) that achieves both a high chip saturation output power and a low chip noise figure (NF) was developed by using a thin multiquantum well with low internal loss. The SOA exhibited a high chip saturation output power of >+19.6 dBm and a low chip NF of <4.5 dB over a 3-dB gain bandwidth of 120 nm (1450-1570 nm). For the amplification of optical signals modulated at 40-Gb/s nonreturn-to-zero format, a penalty-free amplification was confirmed up to an average chip output power of +18.1 dBm.     

Long-wavelength optical fiber communication

Recent research on long-wavelength lightwave communication utilizing the wavelength region between 1.3 and 1.6 µm is reviewed with an eye toward future system development. The attraction of the long-wavelength region is the availability of the ultimately low-loss and wide-band features of the silica fiber, where minimum loss is 0.27 dB/km at a wavelength of 1.3 µm and 0.16 dB/km at 1.55 µm. The single-mode fiber has found its first significant applications in long-wavelength systems. The specific characteristics of lightwave components are discussed with focus on physical fundamentals. The practical performance of fibers and lightwave devices is surveyed. The dynamic properties of long-wavelength laser diodes are discussed in relation to fiber characteristics. The noise characteristics of long-wavelength detectors are considered for the purpose of specifying the repeater spacing. Some system studies are reviewed, for example, 1.3-µm-wavelength lightwave systems, which have demonstrated bandwidth-distance products of about 40 GHz ċ km. Various approaches to extend the capacity of long-wavelength lightwave transmission are given. In the future, the 1.5-µm wavelength system could operate at the lowest loss wavelength region extending from 1.5 to 1.65 µm. Much higher performance, for example, bandwidth-distance products of 185 GHz ċ km, achieved by further continuation of research and development on lightwave sources as well as fibers. Because of the author's familiarity with work in Japan, that work is emphasized and most frequently cited.     

利用导通电压降监测SLD的输出光功率

由于传统的光功率采集仪精度不高,在实验中无法明显地显示出光功率在短期内的变化,而采集电压的数据采集系统可以很好地解决这个问题。在分析1310 nm超辐射发光二极管(Super Luminescent Diode,SLD)光源的工作原理的基础上,设计了一种在恒温条件下控制驱动电流来使SLD稳定工作的驱动电路,进行了理论分析和实验验证,给出了利用SLD电压降监测输出光功率的新方法,取得了真实可靠的实验数据。通过SLD光源的驱动实验得出输出光功率与驱动电流和SLD两端电压降的相关关系,结果表明,输出光功率与电流具有良好的线性关系,与电压具有良好的正相关指数关系。利用采集电压降监测SLD的输出光功率,大大提高了测试精度和数据分辨率,同时为SLD退化寿命试验提供了新的电学参数。     

980 nm高峰值功率微型化VCSEL脉冲激光光源

报道了输出波长980 nm的高峰值功率垂直腔面发射激光器(VCSEL)及其微型化脉冲激光光源.通过优化VCSEL单元器件的结构,有效抑制了宽面VCSEL结构中的非均匀电流分布,提高了单元器件的斜率效率,获得了直径400μm,峰值输出功率62 W的VCSEL单元器件;在此基础上,研制出由单元器件组合封装而成的VCSEL"准列阵"子模块以及集成驱动电路的微型化VCSEL脉冲激光光源,该光源在脉冲驱动条件为30 ns、2 k Hz、105 A条件下的峰值输出功率达到226 W,光脉冲宽度35 ns,中心波长979.4nm,斜率效率达到2.15 W/A.     

Thermal analysis of oxide-confined VCSEL arrays

A thermo-electric 3-D analysis of 980 nm vertical cavity surface emitting laser (VCSEL) arrays based on the finite element method (FEM) is presented in this paper. High performance VCSEL array structures with square mesas are modeled by applying a steady-state 3-D heat dissipation model. Several oxide aperture diameters (D_a), substrate thicknesses, current densities, array sizes, heat flux, and temperature profiles are considered. The analysis shows that the maximum internal temperature of a VCSEL array ranges from 306.5 K for a 20 μm D_a, 100 μm substrate thickness, 666 A/cm² current density, and a 1×1 array size to 412 K for a 5 μm D_a, 300 μm substrate thickness, 1200 A/cm² current density, and a 4×4 array size.     

Bottom-emitting VCSEL's for high-CW optical output power

Bottom-emitting vertical-cavity surface-emitting InGaAs MQW lasers operating in the 980-nm wavelength regime have been designed for high continuous-wave optical output power. Devices of 200-μm active diameter and optimized performance reach 350-mW maximum output power when mounted on a heat sink. 50-μm-size lasers produce 100 mW at 25% electrical to optical power conversion efficiency. Thermal properties and size dependent basic characteristics are investigated in detail     

Scalable high-power, high-speed CW VCSEL arrays

A demonstration of a high-power, high-speed 980 nm vertical-cavity surface-emitting laser array with continuous-wave power of greater than 120 mW and frequency response over 7.5 GHz at room temperature is reported. Experimental results show that copper plating the array elements and flip-chip bonding provides effective thermal management as well as offering uniform current distribution at microwave frequencies. This is verified by the radial dependence of modulation bandwidth. These arrays may be useful for short-range light detection and ranging or free-space optical communications systems.     

一种光输出功率控制电路

分析了光输出功率控制在光通信中的重要性 ,提出了一种有效的光功率控制电路。实验结果表明 ,该电路对调节和稳定光输出功率非常有效。