共查询到20条相似文献,搜索用时 15 毫秒
1.
P. Cancio P. Zeppini P. De Natale S. Taccheo P. Laporta 《Applied physics. B, Lasers and optics》2000,70(6):763-768
Experimental results are reported for the noise characteristics of an Yb-doped fibre amplifier pumped at 975 nm, used as a
booster of a low-noise narrow-linewidth single-frequency 1083-nm wavelength laser diode. The maximum output power of the amplifier
is 1.2 W with a gain larger than 30 dB. An increase of the intensity-noise spectral density relative to the signal, by approximately
6.5 dB, is introduced by the amplification process, due to signal-amplified spontaneous-emission (ASE) beat noise. A remarkable
increase of the noise level with decreasing frequency is observed below ≈35 kHz, probably due to technical noise of the amplifier
pump diodes. The spectral broadening due to amplifier phase noise was measured to be less than 300 Hz with a 5-kHz-linewidth
Nd:YAG laser and that for the 300-kHz-linewidth diode laser at 1083 nm is therefore expected to be in the same range.
Received: 5 October 1999 / Revised version: 2 December 1999 / Published online: 24 March 2000 相似文献
2.
We have achieved intracavity parametric conversion of the radiation from a laser based on Nd:YVO4 with high-power diode pumping. An LiF2- crystal was used as the passive Q-switch for the Nd:YVO4 laser. We have shown that by using an active element in the master laser with a passive region, we can form pulsed laser
beams at a wavelength of 1.57 μm with peak power 3.2 kW and repetition rates up to 80 kHz, with beam quality parameter 1.4–1.8.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 5–8, January–February, 2006. 相似文献
3.
This paper reports the fabrication of J-shaped bent-waveguide superluminescent diodes utilizing an InAlGaAs/AlGaAs quantum dot active region. The emission spectrum of the device is centred at 884 nm with a full width at half maximum of 37 nm and an output power of 18 mW. By incorporating an Al composition into the quantum dot active region, short-wavelength superluminescent diode devices can be obtained. An intersection was found for the light power-injection current curves measured from the straight-waveguide facet and the bent-waveguide facet, respectively. The result is attributed to the conjunct effects of the gain and the additional loss of the bent waveguide. A numerical simulation is performed to verify the qualitative explanation. It is shown that bent waveguide loss is an important factor that affects the output power of J-shaped superluminescent diode devices. 相似文献
4.
理想波导短程透镜的研究 总被引:4,自引:0,他引:4
报道无曲率奇点,无像差光波导短程透镜的研究。在透镜面型设计上,应用前文提出的过渡区母线函数形式,有效地消除了透镜卷边两端的曲率奇点,具体设计和研制了理想光波导短程透镜。 相似文献
5.
J.-R. Chen S.-C. Ling H.-M. Huang P.-Y. Su T.-S. Ko T.-C. Lu H.-C. Kuo Y.-K. Kuo S.-C. Wang 《Applied physics. B, Lasers and optics》2009,95(1):145-153
The optical properties of InGaN multi-quantum-well laser diodes with different polarization-matched AlInGaN barrier layers
have been investigated numerically by employing an advanced device simulation program. The use of quaternary polarization-matched
AlInGaN barrier layers enhances the electron–hole wave function overlap due to the compensation of polarization charges between
InGaN quantum well and AlInGaN barrier layer. According to the simulation results, it is found that, among the polarization-matched
quantum-well structures under study, lower threshold current and higher slope efficiency can be achieved simultaneously when
the aluminum composition in AlInGaN barrier layers is about 10–15%. The optimal polarization-matched InGaN/AlInGaN laser diode
shows lower threshold current and higher slope efficiency compared to conventional InGaN/InGaN laser diodes. 相似文献
6.
S. Duman S. Dogan B. Gürbulak A. Türüt 《Applied Physics A: Materials Science & Processing》2008,92(2):337-340
The effective barrier heights and ideality factors of identically fabricated Ni/n-type 6 H-SiC Schottky diodes (23 dots) have
been calculated from their experimental forward bias current–voltage (I–V) and reverse bias capacitance–voltage (C–V) characteristics.
A statistical study related to the experimental barrier heights (BHs) and ideality factors of the diodes has been made. The
effective Schottky barrier heights (SBHs) and ideality factors obtained from the I–V and C–V characteristics have differed
from diode to diode. The BHs obtained from the I–V characteristics varied from 0.85 to 1.03 eV, the ideality factors varied
from 1.13 to 1.40 and the BHs from C-2–V characteristics varied from 1.10 to 1.70 eV. The experimental BH and ideality factor distributions obtained from the I–V
characteristics are fitted by a Gaussian function, and their mean values are found to be 0.92±0.04 eV and 1.29±0.08 eV, respectively.
The lateral homogeneous SBH value of 1.16 eV for the Ni/n-type 6H-SiC diodes has been calculated from a linear extrapolation
of the effective barrier heights to nif=1.03.
PACS 79.40.+z; 73.40.Sx; 73.30.+y; 71.20.Nr 相似文献
7.
650 nm-range AlGaInP multi-quantum well (MQW) laser diodes grown by low pressure metal organic chemical vapor deposition (LP-MOCVD)
have been studied and the results are presented in this paper. Threshold current density of broad area contact laser diodes
can be as low as 350 A/cm2. Laser diodes with buried-ridge strip waveguide structures were made, threshold currents and differential efficiencies are
(22–40) mA and (0.2–0.7) mW/mA, respectively. Typical output power for the laser diodes is 5 mW, maximum output power of 15
mW has been obtained. Their operation temperature can be up to 90°C under power of 5 mW. After operating under 90°C and 5
mW for 72 hrs, the average increments for the threshold currents of the lasers at 25°C and the operation currents at 5 mW
(at 25°C) are (2–3) mA and (3–5) mA, respectively. Reliability tests showed that no obvious degradation was observed after
1400 hours of CW operation under 50°C and 2.5 mW.
Presented at the 1st Czech-Chinese Workshop “Advanced Materials for Optoelectronics”, Prague, Czech Republic, June 13–17,
1998. 相似文献
8.
It is shown that nearly ideal current-voltage characteristics (I-V curves) can be obtained for small-area, shallow silicon diffused p-n junctions irradiated with 60Co gamma rays in the dose range 103–5×105 Gy. In the irradiated diodes the current transfer mechanism is observed to shift from generation-recombination to diffusion.
The nonideality factor on the forward branch of the I-V curve decreases from 1.68 in the unirradiated diode to 1.17 in a diode irradiated to a dose of 5×105 Gy. A saturation current is observed on the reverse branch of the I-V curves of irradiated diodes at room temperature.
Zh. Tekh. Fiz. 68, 131–132 (October 1998) 相似文献
9.
L. I. Burov A. S. Gorbatsevich A. G. Ryabtsev G. I. Ryabtsev A. N. Imenkov Yu. P. Yakovlev 《Journal of Applied Spectroscopy》2008,75(6):805-809
The spatial distribution of emission intensity in the active layer of a laser diode (LD) based on an InAsSb/InAsSbP heterostructure
(generation wavelength λgen ∼ 3.3 μm) is obtained for various stripe widths w by means of numerical solution of the wave equation in the 2D approximation
taking into account the refractive index nonlinearity. It has been shown that the special distribution of emission intensity
becomes strongly inhomogeneous at w values exceeding 9–10 μm, which results in the appearance of additional maxima in the
far-field pattern. Calculated far-field patterns in the active layer plane of the LD agree with corresponding experimental
data.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 804–808, November–December, 2008. 相似文献
10.
A. V. Belyakov M. Yu. Perov A. V. Yakimov L. K. J. Vandamme 《Radiophysics and Quantum Electronics》2006,49(5):397-405
We study the low-frequency electric noise characteristics of light-emitting diodes with InAs quantum dots in a GaInAs layer.
Burst noise having the character of random telegraph signal (RTS) is found against the 1/f noise background in the noise voltage of some specimens. A procedure based on the standard theory of signal detection against
the noise background is proposed for a separate study of these noise components. It is found that Hooge’s empirical relation
applied to p-n diodes for the first time by Kleinpenning is also applicable to 1/f noise in quantum-dot diodes. The current dependences of statistical characteristics of the 1/f and RTS noise components are compared to show that the physical origins of RTS noise and 1/f noise in the studied specimens are different.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 5, pp. 437–447, May 2006. 相似文献
11.
12.
The use of laser diodes to excite atomic fluorescence for chemical analysis is investigated. Operating conditions for the laser diode, optical schematic, results, and calibration curve are provided. 相似文献
13.
利用二极管的电压电流波形计算了电子束参数,建立了串级二极管和四路并联二极管阳极靶蒙特卡罗粒子输运计算模型,给出了两种情况下轫致辐射X射线场参数。结果表明:阳极靶厚度增加时,轫致辐射X射线平均能量增大,而能量转换效率先增大,后减小;距离串级二极管和四路并联二极管阳极靶5cm位置处,X射线注量分别为76.50,3.74mJ/cm2;光子平均能量分别为81.13,60.77keV;半径为12cm的圆面上,串级二极管X射线剂量呈马鞍形分布,均匀性为1.70∶1;边长为52cm的正方形平面上,四路并联二极管X射线剂量均匀性小于6.30∶1;电子束轫致辐射转换效率分别为0.29%,0.32%。 相似文献
14.
V. I. Shashkin Yu. A. Dryagin V. R. Zakamov S. V. Krivov L. M. Kukin A. V. Murel’ Yu. I. Chechenin 《Radiophysics and Quantum Electronics》2007,50(12):973-982
We discuss the concept of developing a millimeter-wave multielement matrix receiver on the basis of planar antennas with directly
coupled low-barrier Schottky diodes. Three main problems are considered which involve choosing and developing a design of
the planar antenna coupled with the low-barrier Schottky diode, optimizing the parameters of the low-barrier Schottky diodes
for obtaining maximum sensitivity, and ensuring compact arrangement with weak mutual influence of the planar detectors in
a two-dimensional array. We propose a design of the slot antenna with an active resistance of about 800 Ω at a resonant frequency
of 94 GHz. The detection characteristics of diodes with the differential Schottky-barrier resistance in the range Rj = 0.4–1000 kΩ for a zero bias are studied experimentally. The mutual influence of the neighboring antennas is examined for
developing the multielement radio-imaging system. The conditions of weak cross influence of the closely located planar detectors
are determined.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 12, pp. 1077–1087, December 2007. 相似文献
15.
FANG Gaozhan XIAO Jianwei MA Xiaoyu Xu Zuntu ZHANG Jinming Tan Manqing LIU Zongshun LIU Suping FENG Xiaoming 《中国光学快报(英文版)》2002,11(1)
The 940 nm Al-free active region laser diodes and bars with a broad waveguide were designed and fabricated. The stuctures were grown by metal organic chemical vapour deposition. The devices show excellent performances. The maximum output power of 6.7 W in the 100 μm broad-area laser diodes has been measured, and is 2.5 times higher than that in the Al-containing active region laser diodes with a narrow waveguide and 1.7 times higher than that in Al-free active region laser diodes with a narrow waveguide. The 19% fill-factor laser diode bars emit 33 W, and they can operate at 15W with low degradation rates. 相似文献
16.
High Power 940 nm Al-free Active Region Laser Diodes and Bars with a Broad Waveguide 总被引:1,自引:0,他引:1
FANG Gaozhan XIAO Jianwei MA Xiaoyu XU Zuntu ZHANG Jinming TAN Manqing LIU Zongshun LIU Suping FENG Xiaoming 《Chinese Journal of Lasers》2002,11(1):9-13
1 Introduction High powerlaserdiodescoveringthewavelengthrangefrom 91 0nmto 940nmarewidelyusedforpumpingYb∶YAGsolid statelasers,pumpingytterbium erbiumdopedfiberamplifer (YEDFA ) ,soldering ,materialprocessing,andmedicaltherapy .Inordertoachievehigherpower,highr… 相似文献
17.
18.
本文从理论上对1.3μm InGaAsP/InP窗口吸收区结构超辐射发光二极管进行了优化设计.并在考虑增益饱和和热效应的条件下,用耦合速率方程模拟计算了该结构超辐射发光二极管的功率输出特性.分析研究了窗口区长、泵浦区长、有源层厚度和输出腔面反射率对其输出特性的影响.研究结果表明,由于窗口吸收区的有效散射和吸收,很好地抑制了F-P受激振荡,可用于实现高性能超辐射发光二极管. 相似文献
19.
A self-mixing interferometer is proposed to measure nanometre-scale optical path length changes in the interferometer’s external
cavity. As light source, the developed technique uses a blue emitting GaN laser diode. An external reflector, a silicon mirror,
driven by a piezo nanopositioner is used to produce an interference signal which is detected with the monitor photodiode of
the laser diode. Changing the optical path length of the external cavity introduces a phase difference to the interference
signal. This phase difference is detected using a signal processing algorithm based on Pearson’s correlation coefficient and
cubic spline interpolation techniques. The results show that the average deviation between the measured and actual displacements
of the silicon mirror is 3.1 nm in the 0–110 nm displacement range. Moreover, the measured displacements follow linearly the
actual displacement of the silicon mirror. Finally, the paper considers the effects produced by the temperature and current
stability of the laser diode as well as dispersion effects in the external cavity of the interferometer. These reduce the
sensor’s measurement accuracy especially in long-term measurements. 相似文献
20.
Thin-film metal-oxide-metal (MOM) diodes were fabricated by a positivephotoresist process using iron oxide and chromium masks.
Reproducible junctions were obtained with areas of 2 μm2. The diodes exhibit stable, highly nonlinear I–V characteristics. Several hundred diodes were printed on the same substrate
with nonlinearity parameters varying less than 15%. Infrared rectification was tested with a stabilized 10.6 μm CO2 laser. 相似文献