共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
用量子阱激光器增益与载流子浓度的对数关系(增益饱和效应)取代了体材料的线性关系,得到了适用于量子阱结构的速率方程。详细分析和计算了这一修正的影响。计算表明,对长腔(低损耗)器件线性关系是较好的近似;对短腔(高损耗)、线性关系则有较大的误差,必须考虑增益饱和的影响,否则将过高估算自发辐射因子的测量值,过高估计弛豫振荡频率和最大调制频率。这一结果对微腔激光器的研究具有重要的意义。 相似文献
3.
适用于量子阱激光器的速率方程 总被引:3,自引:2,他引:1
首次在理论上用量子阱激光器增益与载流子密度的对数关系替代了原有速率方程中的线性关系,得到了改进了速率方程,分析了稳态和调制特性,从理论上得到了获得最低阈值的最佳阱数和最大调制带宽的最佳腔长。 相似文献
4.
5.
6.
7.
微腔半导体激光器的两种新调制方法 总被引:3,自引:0,他引:3
本文提出微腔半导体激光器的两种新调制方法:自发发射寿命调制和光子寿命调制。小信号近似分析的数值模拟结果表明,这两种调制方法的调制带宽大于同参数下的电流调制的带宽。 相似文献
8.
9.
10.
报道一种用作光通讯光源的外腔锁模多量子阱结构半导体激光器,其脉冲宽度2~5ps,波长调谐范围为1.52~1.57μm,锁模频率0.5~1.0GHz平均输出光功率为1mW。 相似文献
11.
从理论上分析了无反转自由电子激光器的原理,并提出了一个新的无反转自由电子激光器的实现方案。通过增加两块电子反射镜,使电子受激辐射的几率幅相干叠加,得到的增益两倍于原有的方案。 相似文献
12.
13.
有机薄膜电致发光器件的光学微腔效应 总被引:2,自引:0,他引:2
制备了以铝掺杂氧化锌(AZO)透明导电膜为阳极的有机薄膜电致发光微腔器件,研究了垂直的光学法布里-珀罗微共振腔对有机器件的自发发射的微腔效应,发出了光谱窄化、发光强度增加及发射的角度依赖关系等现象。具有微腔结构的器件发射谱将高宽只有14display status 相似文献
14.
This paper studies power dependent photoluminescence spectra, the
stimulated emission occurring at ultraviolet (UV) band instead of the
green emission band of ZnO nanowires, which are prepared with a
chemical reduction method. The dynamics of the UV emission and green
emission
is given to demonstrate the reason of stimulated emission occurring at UV
band but not the green emission band under high excitation, which indicates
that the slow decay rate of trap state makes it easy to be fully filled and
saturated, while the fast decay rate of near-band-edge exciton state makes
the UV emission dominate the radiative recombination under high excitation.
The UV emission, as well as the corresponding stimulated emission, occurs in
competition with the green deep-trap emission. In addition, when pump
fluence further increases, the multiple lasing modes appear. The dependence
of these lasing modes on the pump fluence is first discussed. This diagram
should be helpful to understand and design the optical nanodevices of ZnO
nanowires. 相似文献
15.
16.
Integration of microcavity-based coherent light sources and waveguides is of central importance for building optical networks and photonic circuits. However, such combined devices face severe challenges in distributing the generated signals to designed ends despite that the significant advances are accomplished in emission modulation and controlling. Herein, dynamically all-optical control of the outputs from the microcavity by employing parity-time (PT) symmetry is demonstrated. By exploiting the interplay between gain and loss in a waveguide-connected microsquare cavity, the mode field distributions can be strongly modified when the non-Hermitian system enters PT-symmetry breaking phase. Numerical calculations and the corresponding Husimi projections unambiguously show the PT-symmetry-induced mode localization and output redistributions in microsquare cavity. Notably, the intensity ratios of the lights collected by the two channels can be directly tuned over two orders of magnitude with the increase of pumping strength. These findings will be essential for understanding the fundamentals of non-Hermitian optics and advancing the application potentials of microcavity system in integrated photonics. 相似文献
17.
复合腔全光纤环形激光器单纵模双向同时激射的实验研究 总被引:5,自引:0,他引:5
提出并实验证实了三能级掺杂光纤复合腔环形激光器共振选模振荡原理和腔内自建可饱和吸收机制对双向行波共振谱的去耦作用,并实现复合腔掺Er^3+全光纤环形激光器单纵蓦以向同时激射。 相似文献
18.
L. I. Burov E. V. Lebedok V. K. Kononenko A. G. Ryabtsev G. I. Ryabtsev 《Journal of Applied Spectroscopy》2007,74(6):878-883
By comparing experimental and theoretical radiative recombination spectra, we have determined the values of the square of
the matrix element for interband optical transitions |M|2 in epitaxial GaN at different temperatures T. The data obtained were used to analyze the mechanism for the temperature dependence
of the lasing threshold for a GaN laser. In the experiments, we used epitaxial layers of GaN with a wurtzite crystal structure,
grown on Al2O3 (0001) substrates and excited by a focused beam from a nitrogen laser. We have shown that the spontaneous emission spectra
near the lasing threshold of a GaN laser are consistent with the model of optical interband transitions not obeying a selection
rule for the electron wave vector. As we have established, the parameter |M|2 practically does not vary for T = 300–470 K: 5.4·10−73 kg2·m5/sec2. Further increase in the temperature leads to an exponential fall-off in |M|2 down to 3.4·10−73 kg2·m5/sec2 at T ≈ 520 K. Such behavior of |M|2 as a function of temperature correlates with the sudden increase in the nonradiative recombination rate at T > 470 K, and
may be connected with a change in the recombination mechanisms in the active layer of the GaN laser in the high temperature
region.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 790–794, November–December, 2007. 相似文献
19.
20.
Vlasov kinetic theory of the free electron laser employing waveguide frifting tube and helical pump is presented. Distinct from the former theories this theory has (1) taken into account the 3-d structure of the scattering field; (2) applied the plasma kinetic theory, which is more accurate than the other methods, to analysing the effect of the longitudinal. field; (3) taken account of the influence of the annular structure of the beam. The magnetic resonant effect appearing when the cyclotron frequency of electrons approaches the effective frequency of the magnetic pump is analysed and the growth rate formula in the linear regime derived. Results show that on taking into account the 3-d structure of the field and beam, one cannot arbitrarily choose the radius of the hollow beam, or else within certain range the instability may disappear altogether. Lastly, the equation for determination of the optimum beam radius is given and the possibility of raising growth rate by operating in high order modes shown. 相似文献