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研究了激光二极管(LD)抽运的自拉曼Nd∶YVO4调Q激光器的特性。Nd∶YVO4晶体同时作为激光介质和拉曼晶体,通过声光调Q技术,产生了1176 nm的拉曼激光。测量了平均输出功率、脉冲宽度和单脉冲能量随抽运功率和脉冲重复率的变化。典型的1064 nm基频光和1176 nm拉曼光脉冲的脉冲宽度分别为26.3 ns和9.0 ns。在脉冲重复率为20 kHz,抽运功率为8.46 W时,产生了平均功率为0.384 W的1176 nm光的输出,光-光转换效率为4.54%。使用速率方程对自拉曼Nd∶YVO4调Q激光器特性进行了理论研究,把脉冲重复率为10 kHz,20 kHz,30 kHz时拉曼光单脉冲能量和脉冲宽度的实验值与理论值进行了比较,结果基本相符。 相似文献
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激光二极管抽运的自拉曼Nd:YVO4激光器 总被引:2,自引:1,他引:2
研究了激光二极管(LD)抽运的白拉曼Nd:YVO4调Q激光器的特性。Nd:YVO4晶体同时作为激光介质和拉曼晶体,通过声光调Q技术,产生了1176nm的拉曼激光。测量了平均输出功率、脉冲宽度和单脉冲能量随抽运功率和脉冲重复率的变化。典型的1064nm基频光和1176nm拉曼光脉冲的脉冲宽度分别为26.3ns和9.0ns。在脉冲重复率为20kHz,抽运功率为8.46W时,产生了平均功率为0.384W的1176nm光的输出,光-光转换效率为4.54%。使用速率方程对白拉曼Nd:YVO4调Q激光器特性进行了理论研究,把脉冲重复率为10kHz,20kHz,30kHz时拉曼光单脉冲能量和脉冲宽度的实验值与理论值进行了比较,结果基本相符。 相似文献
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研究了激光二极管(LD)端面抽运的主动调Q内腔式Nd∶YAG/GdVO4拉曼激光器的激光特性,测量了不同抽运功率和脉冲重复频率条件下的平均输出功率和脉冲宽度.当注入的抽运功率为[7.44 W,脉冲重复频率为20 kHz时获得的1174.5 nm拉曼光的最大平均输出功率为1.3 W,对应的光-光转换效率为17.4%;当注入抽运功率为6.8 W,脉冲重复频率为[15 kHz时获得的1174.5 nm拉曼光的最大单脉冲能量为74.4 μJ.与Nd∶GdVO4自拉曼激光器进行实验比较和分析,实验结果表明主动调Q内腔式Nd∶YAG/GdVO4拉曼激光器可以获得比Nd∶GdVO4自拉曼激光器更高的平均输出功率和转换效率. 相似文献
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报道了全固态脉冲运转腔外四倍频289.9 nm紫外激光器。首先,基于Nd∶KGW晶体的受激拉曼散射机制,以Nd∶YVO4晶体作为增益介质,结合声光调Q技术,研制了一台1159.31 nm红外拉曼激光器。当二极管阵列的总抽运功率为20 W时,1159.31 nm激光的输出功率为983 m W,脉宽为13.5 ns。依次利用Ⅰ类相位匹配偏硼酸锂(LBO)和偏硼酸钡(BBO)晶体进行腔外二倍频和四倍频,实现了平均功率为108 m W的289.9 nm紫外激光输出,重复频率为10 k Hz,脉冲宽度为8 ns,峰值功率为1.35 k W,四倍频转化效率为11%。测量了紫外激光的输出光斑,分析了平均功率随脉冲频率的变化关系。 相似文献
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报道了一台激光二极管(LD)端面抽运Nd:YVO4晶体,利用两块LBO品体进行内腔二倍频和三倍频,实现了高效率、高峰值功率355 nm激光准连续输出的紧凑型全固态紫外激光器.激光腔采用简单平平直腔,腔长仅108 mm.当注入抽运功率6.76 W,重复频率20 kHz时,355 nm激光输出平均功率最高达245 mW,相应的光光转换效率为3.62%,脉冲宽度为8.0 ns,脉冲峰值功率为1.52 kW,输出功率短期不稳定性小于4.2%,光束质量良好.通过采用内腔倍频技术和设计合理的腔结构,整台激光器结构紧凑,体积小巧,便携性强,适合于中小功率紫外激光的输出,有利于进一步拓宽紫外激光器的应用领域. 相似文献
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Wei-Chou Hsu Dong-Hai Huang Yu-Shyan Lin Yeong-Jia Chen Jun-Chin Huang Chang-Luen Wu 《Electron Devices, IEEE Transactions on》2006,53(3):406-412
This paper proposes a In/sub 0.5/Al/sub 0.5/As/In/sub x/Ga/sub 1-x/As/In/sub 0.5/Al/sub 0.5/As (x=0.3-0.5-0.3) metamorphic high-electron mobility transistor with tensile-strained channel. The tensile-strained channel structure exhibits significant improvements in dc and RF characteristics, including extrinsic transconductance, current driving capability, thermal stability, unity-gain cutoff frequency, maximum oscillation frequency, output power, power gain, and power added efficiency. 相似文献
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《Electronics letters》1990,26(1):27-28
AlGaAs/GaInAs/GaAs pseudomorphic HEMTs with an InAs mole fraction as high as 35% in the channel has been successfully fabricated. The device exhibits a maximum extrinsic transconductance of 700 mS/mm. At 18 GHz, a minimum noise figure of 0.55 dB with 15.0 dB associated gain was measured. At 60 GHz, a minimum noise figure as low as 1.6 dB with 7.6 dB associated gain was also obtained. This is the best noise performance yet reported for GaAs-based HEMTs.<> 相似文献
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A 12 /spl times/ 12 In/sub 0.53/Ga/sub 0.47/As-In/sub 0.52/Al/sub 0.48/As avalanche photodiode array
Zheng X.G. Hsu J.S. Sun X. Hurst J.B. Li X. Wang S. Holmes A.L.Jr. Campbell J.C. Huntington A.S. Coldren L.A. 《Quantum Electronics, IEEE Journal of》2002,38(11):1536-1540
We report a 12 /spl times/ 12 In/sub 0.53/Ga/sub 0.47/As-In/sub 0.52/Al/sub 0.48/As avalanche photodiode (APD) array. The mean breakdown voltage of the APD was 57.9 V and the standard deviation was less than 0.1 V. The mean dark current was /spl sim/2 and /spl sim/300 nA, and the standard deviation was /spl sim/0.19 and /spl sim/60 nA at unity gain (V/sub bias/ = 13.5 V) and at 90% of the breakdown voltage, respectively. External quantum efficiency was above 40% in the wavelength range from 1.0 to 1.6 /spl mu/m. It was /spl sim/57% and /spl sim/45% at 1.3 and 1.55 /spl mu/m, respectively. A bandwidth of 13 GHz was achieved at low gain. 相似文献
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S. Privitera F. Wang P. Dumont-Girard K. Liu C. Bongiorno 《Microelectronic Engineering》2010,87(3):430-433
SixCryCzBv thin films with several compositions have been studied for integration of high precision resistors in 0.8 μm BICMOS technology. These resistors, integrated in the back-end of line, have the advantage to provide high level of integration and attractive electrical behavior in temperature, for analog devices. The film morphology and the structure have been investigated through transmission electron microscopy analysis and have been then related to the electrical properties on the base of the percolation theory. According to this theory, and in agreement with experimental results, negative thermal coefficient of resistance (TCR) has been obtained for samples with low Cr content, corresponding to a crystalline volume fraction below the percolation threshold.Samples with higher Cr content exhibit, instead, a variation of the TCR as a function of film thickness: negative TCR values are obtained for thickness lower than 5 nm, corresponding to a crystalline volume fraction below the percolation threshold; positive TCR are obtained for larger thickness, indicating the establishment of a continuous conductive path between the Cr rich grains. This property seems to be determinant in order to assure the possibility to obtain thin film resistors almost independent on the temperature. 相似文献
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Patrick W. C. Ho Firas Odai Hatem Haider Abbas F. Almuri T. Nandha Kumar 《半导体学报》2016,37(6):064001-13
Nonvolatile memories have emerged in recent years and have become a leading candidate towards replacing dynamic and static random-access memory devices. In this article, the performances of TiO2 and TaO2 nonvolatile memristive devices were compared and the factors that make TaO2 memristive devices better than TiO2 memristive devices were studied. TaO2 memristive devices have shown better endurance performances (108 times more switching cycles) and faster switching speed (5 times) than TiO2 memristive devices. Electroforming of TaO2 memristive devices requires~4.5 times less energy than TiO2 memristive devices of a similar size. The retention period of TaO2 memristive devices is expected to exceed 10 years with sufficient experimental evidence. In addition to comparing device performances, this article also explains the differences in physical device structure, switching mechanism, and resistance switching performances of TiO2 and TaO2 memristive devices. This article summarizes the reasons that give TaO2 memristive devices the advantage over TiO2 memristive devices, in terms of electroformation, switching speed, and endurance. 相似文献
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Yi-Jen Chan Ming-Ta Yang 《Electron Devices, IEEE Transactions on》1995,42(10):1745-1749
The properties of both lattice-matched and strained doped-channel field-effect transistors (DCFET's) have been investigated in AlGaAs/In/sub x/Ga/sub 1-x/As (0/spl les/x/spl les/0.25) heterostructures with various indium mole fractions. Through electrical characterization of grown layers in conjunction with the dc and microwave device characteristics, we observed that the introduction of a 150-/spl Aring/ thick strained In/sub 0.15/Ga/sub 0.85/As channel can enhance device performance, compared to the lattice-matched one. However, a degradation of device performance was observed for larger indium mole fractions, up to x=0.25, which is associated with strain relaxation in this highly strained channel. DCFET's also preserved a more reliable performance after biased-stress testings.<> 相似文献
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Jie Liu Yugang Zhou Rongming Chu Yong Cai Chen K.J. Lau K.M. 《Electron Device Letters, IEEE》2005,26(3):145-147
We report an Al/sub 0.3/Ga/sub 0.7/N-Al/sub 0.05/Ga/sub 0.95/N-GaN composite-channel HEMT with enhanced linearity. By engineering the channel region, i.e., inserting a 6-nm-thick AlGaN layer with 5% Al composition in the channel region, a composite-channel HEMT was demonstrated. Transconductance and cutoff frequencies of a 1 /spl times/100 /spl mu/m HEMT are kept near their peak values throughout the low- and high-current operating levels, a desirable feature for linear power amplifiers. The composite-channel HEMT exhibits a peak transconductance of 150 mS/mm, a peak current gain cutoff frequency (f/sub T/) of 12 GHz and a peak power gain cutoff frequency (f/sub max/) of 30 GHz. For devices grown on sapphire substrate, maximum power density of 3.38 W/mm, power-added efficiency of 45% are obtained at 2 GHz. The output third-order intercept point (OIP3) is 33.2 dBm from two-tone measurement at 2 GHz. 相似文献
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Visible light-emitting diodes (LEDs) emitting at 615 nm and employing the AlGaInP/GaInP double heterostructure (DH) grown on a lattice-matched GaAs/sub 0.7/P/sub 0.3/ substrate have been fabricated for the first. The external quantum efficiency of 0.156% for the orange LEDs can be achieved by introducing the GaP material as the current spreader and window layer for the DH LEDs.<> 相似文献