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1.
The effect of radiation gain saturation in quantum-well heretostructures was investigated in the system GaAs—AlGaAs with regard
to the spectral line broadening and the type of radiation polarization.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 6, pp. 797–800, November–December, 1997. 相似文献
2.
The polarization characteristics of the radiation produced by a quantum-well heterolaser with a nonselective resonator were considered theoretically (with account for spectral broadening) at different values of the loss coefficient. The dependence of the radiation intensity on the pumping current has been obtained for a set of longitudinal modes. The change in the degree of polarization depending on the ratio between the coefficients of optical losses for TE and TM modes has been established. 相似文献
3.
The influence of various lasing-radiation polarization states and types of optical dipole transitions on the nonlinear amplitude-detuning characteristics of quantum-well semiconductor lasers with pump current modulation has been theoretically investigated. It has been established that the narrowest spectral interval, where the response is nonzero, is realized in the case of TM-mode radiation and transitions to the heavy-hole states as well as in the case of TE-mode radiation and transitions to the light-hole states. 相似文献
4.
An analysis of the power-current and tuning characteristics of asymmetric multiple-layer inhomogeneously pumped quantum-well
lasers with mode selection in the external resonator was performed. It is shown that the choice of the parameters of the barrier
and active layers of the laser heterostructure and optimization of the dispersion characteristics of the selective element
of the external resonator make it possible to realize continuous tuning of the lasing wavelength in a wide spectral range
at a practically constant output radiation power.
Reported at the Second International Scientific and Technical Conference on Quantum Electronics, Minsk, November 23–25, 1998.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 5, pp. 687–692, September–October, 1999. 相似文献
5.
A steady-state rate-equation model for temperature-dependent luminescence spectra from localized-state material system is presented. The effects of thermal emission, recapturing, radiative and nonradiative recombination are taken into account in the model. Two localized-state material systems, including InAs/GaAs quantum-dot and InGaN/GaN-multi-quantum-well samples were prepared. It is found that the temperature-dependent behaviors of luminescence emission energy obtained from the two samples are quite different. In the mid-temperature range, the emission peaks exhibit a redshift for quantum-dot sample, but a blueshift for multi-quantum-well sample. The peak energies of the luminescence spectra are simulated in this model and show a good agreement with experiment. The corresponding luminescence mechanisms of carriers in localized-state material systems, which lead to the diversity are quantitatively discussed in detail by the model. 相似文献
6.
The principal features of changing (sweeping) the "instantaneous" emission frequency of quantum-well heterolasers as functions
of the modulation frequency and depth and the constant component of the pump current when tuning the lasing frequency within
the gain band are established using numerical modeling. The active medium is described in the framework of a two-band model
with similar distributions of levels in subbands of electrons and holes assuming transitions between ground subbands with
no k-selection rule. Emission frequency sweeping occurs because of changes in both the index of refraction of the active medium
due to a variation in the concentration of non-equilibrium charge carriers and the forbidden-band gap. Emission frequency
sweeping does not occur at low frequencies of current modulation that correspond with quasi-stationary lasing regimes. The
modulation depth of the output radiation and, therefore, the emission frequency sweeping, also approach zero for the other
limiting case of relatively high current modulation frequencies. The sweeping is greatest at intermediate current modulation
frequencies. The sweeping value is approximately halved in certain instances by taking into account the change of forbidden-band
gap of the semiconductor. In general, the sweeping value is determined by the combined effect of the modulation frequency
and depth, the constant component of the pump current, and the spectral position of the laser emission frequency within the
gain band.
Presented at the VIIth International Scientific Conference "Laser physics and optical technologies," June 17–19, 2008, Minsk,
and at the VIIth International Scientific Technical Conference "Quantum electronics," October 13–16, 2008, Minsk, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 2, pp. 194–201, March–April, 2009. 相似文献
7.
采用一个光谱匹配的太赫兹(THz)量子阱探测器(QWP)研究了一激射频率约为41 THz的THz量子级联激光器(QCL)在不同驱动电流下的发射谱,分析了测量得到的发射谱谱型和谱峰位置,根据测量的发射谱估算了太赫兹量子级联激光器发射功率随驱动电流变化的情况,从而得到了THz QCL激射的电流密度范围及其阈值电流密度.文中还研究了THz QWP在不同温度下对THz QCL 激光辐射的响应特性.研究结果表明,THz QWP在表征THz QCL的发射谱方面是一种很好的探测器,并有望成为未来THz通信中的接收装置. 相似文献
8.
采用一个光谱匹配的太赫兹(THz)量子阱探测器(QWP)研究了一激射频率约为41 THz的THz量子级联激光器(QCL)在不同驱动电流下的发射谱,分析了测量得到的发射谱谱型和谱峰位置,根据测量的发射谱估算了太赫兹量子级联激光器发射功率随驱动电流变化的情况,从而得到了THz QCL激射的电流密度范围及其阈值电流密度.文中还研究了THz QWP在不同温度下对THz QCL 激光辐射的响应特性.研究结果表明,THz QWP在表征THz QCL的发射谱方面是一种很好的探测器,并有望成为未来THz通信中的接收装置.
关键词:
太赫兹量子阱探测器
太赫兹量子级联激光器
太赫兹通信
Fourier变换红外光谱 相似文献
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11.
The statistics of polarization in electromagnetic waves or target vector has been studied deeply, generally using Stokes parameters. Unfortunately, all the data-processing includes the assumption that the sampling data are independent of time, without a consideration of the time coherence of the polarization data, such as instantaneous Stokes parameters. In this paper, the definitions of the instantaneous coherent polarization function and polarimetric spectrum are presented for the first time, which shows the coherences of the instantaneous Stokes parameters in both time and frequency domain, even in spatial coherence. The new formula of definition can be extended to spatial propagation coherence, both in free space or any linear medium. 相似文献
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13.
A. A. Afonenko V. M. Stetsik V. Ya. Aleshkin V. I. Gavrilenko A. A. Dubinov S. V. Morozov B. N. Zvonkov S. M. Nekorkin 《Journal of Applied Spectroscopy》2007,74(4):589-593
We studied the dynamic characteristics of InGaAs/GaAs/InGaP quantum-well lasers generating at two wavelengths of about 1 μm
with a spectral separation of 15–40 nm. We observed experimentally regimes of jumplike switching and self-sustained pulsations
of radiation. The influence of ballistic transfer of carriers during intraband absorption on the production of positive feedback
in the dynamic system is studied theoretically.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 533–536, July–August, 2007. 相似文献
14.
We theoretically investigate the optical properties of an ultra-thin InN layer embedded in InGaN matrix for light emitters. The peak emission wavelength extends from ultraviolet (374 nm) to green (536 nm) with InN quantum well thickness increasing from 1 monolayer to 2 monolayers, while the overlap of electron-hole wave function remains at a high level (larger than 90%). Increase of In content in InGaN matrix provides a better approach to longer wavelength emission, which only reduces the spontaneous emission rate slightly compared with the case of increasing In content of the conventional InGaN quantum well. Also, the transparency carrier density derived from gain spectrum is of the same order as that in the conventional blue laser diode. Our study provides skillful design on the development of novel structure InN-based light emitting diodes as well as laser diodes. 相似文献
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16.
Design of broadband hybrid fiber amplifier based on particle swarm optimization algorithm北大核心CSCD
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基于铒/镱共掺光纤放大器(erbium-ytterbium doped fiber amplifier, EYDFA)的理论模型和受激拉曼散射效应的分析理论,利用EYDFA和拉曼光纤放大器(Raman fiber amplifier, RFA)的增益谱互补特性,研究并设计了EYDFA与二阶多泵浦RFA相结合的混合放大器结构。为了得到高增益和低平坦度的混合放大器,引入了粒子群算法优化泵浦光波长和功率。仿真结果表明:在不使用增益均衡器的条件下,所设计的混合光纤放大器在输出端得到了近似相等的输出光功率,在90 nm的带宽范围内平均增益为38.78 dB,增益平坦度为1.1 dB,为混合放大器的设计和优化提供了参考。 相似文献
17.
矢量调制器因其自身结构小、功耗低等特点已广泛应用于雷达、导航、仪器仪表及卫星通信等领域。基于矢量调制器的最大等增益圆理论,深入分析了增益圆点、半径与调制器增益输出的关系,设计出一种可全频段扫描、一键自动测试的通用矢量调制器增益控制方案,实现了对矢量调制器增益输出以及其平坦度的精确控制,并可灵活设置矢量调制器的精度和平坦度指标,提高了矢量调制器的性能以及校准效率。验证对象为Hittite Microwave公司的HMC1097LP4E矢量调制芯片,单点验证时间不超过1min,增益控制精度可达0.1dB,平坦度可达0.5dB。 相似文献
18.
《Physics letters. A》2020,384(29):126758
Three metamaterial samples were simulated, numerically analyzed, and fabricated with different resonator lengths on similar unit cells. According to the results in addition to conventional LC resonance of the resonator, standing wave resonance was also observed within the resonator-dielectric-grounded back wire waveguide. We observed that the orientation of the sides of this waveguide relative to the polarization of the incident electromagnetic wave has a direct effect on the resonant frequency. The best asymmetric shape of the resonator with the minimum reflection coefficient in a wide frequency range of about 5.5 GHz with only 3% of reflection was introduced. According to the results, metamaterial polarizers and optical filters can be produced based on the standing wave resonances. 相似文献
19.
We investigated the possibility of describing the processes of radiation generation at two spectrally spaced wavelengths in
quantum-dimensional lasers based on asymmetric heterostructures by means of rate equations that take account of the effects
of nonlinear amplification. We show that agreement between experimental and theoretical results is achieved in the case where
it is assumed that the processes of interaction between spectrally spaced modes prevail over the processes of self-stress
of the modes. An analysis of various mechanisms of nonlinear amplification is carried out, and it is found that dynamic heating
of charge carriers by radiation is a reason for nonlinear phenomena with the features indicated.
To whom correspondence should be addressed.
Reported at the Second International Scientific and Technical Conference on Quantum Electronics, Minsk, November 23–25, 1998.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 5, pp. 697–702, September–October, 1999. 相似文献
20.
与目前商用的太赫兹源相比,自旋太赫兹源具有超宽频谱、固态稳定以及成本低廉等优点,这使其成为下一代太赫兹源的主要研究焦点.但使用自旋太赫兹源时,通常需要外加磁场使铁磁层的磁化强度饱和,才能产生太赫兹波,这制约了其应用前景.基于此,本文制备了一种基于Ir Mn/Fe/Pt交换偏置结构的自旋太赫兹波发生器,通过Ir Mn/Fe中的交换偏置场和Fe/Pt中的超快自旋流注入与逆自旋霍尔效应相结合,在无外加磁场下产生了强度可观的太赫兹波.在Ir Mn和Fe的界面中插入超薄的Cu,可以使Fe在厚度很薄时零场下实现饱和磁化,并且其正向饱和场最高可达–10 m T,从而进一步提升无场下的太赫兹发射效率.零场下出射的太赫兹波的动态范围超过60 d B,达到可实用化的水平.通过旋转样品,发现产生的太赫兹波的偏振方向也会随之旋转,并且始终沿着面内垂直于交换偏置场的方向.此外,在此交换偏置结构的基础上,引入了一层自由的铁磁金属层Fe,设计了一种以Ir Mn/Fe/Pt/Fe为核心结构的自旋阀太赫兹源,发现产生的太赫兹强度在两层铁磁层反平行排列时比平行排列以及不引入自由铁磁金属层时均大约提升了40%.结果表明,基... 相似文献