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1.
The gain properties and valence subbands of InGaAsN/GaAsN quantum-well structures are numerically investigated with a self-consistent LASTIP simulation program. The simulation results show that the InGaAsN/GaAsN has lower transparency carrier density than the conventional InGaAsP/InP material system for 1.3-μm semiconductor lasers. The material gain and radiative current density of InGaAsN/GaAsN with different compressive strains in quantum well and tensile strains in barrier are also studied. The material gain and radiative current density as functions of strain in quantum well and barrier are determined. The simulation results suggest that the laser performance and Auger recombination rate of the 1.3-μm InGaAsN semiconductor laser may be markedly improved when the traditional GaAs barriers are replaced with the AlGaAs graded barriers. 相似文献
2.
The optical characteristics of ultraviolet-violet InGaN laser diodes with different numbers of quantum wells under normal and reversed polarizations are numerically investigated. For the laser structures under normal polarization, the lowest threshold current is obtained when the number of quantum wells is two in the spectral range of 380-408 nm. For the laser structures under reversed polarization, the single quantum-well laser structure possesses the lowest threshold current. The simulation results suggest that the physical origin for these phenomena is caused by the sufficiently suppressed electron and hole leakage currents when the laser diode is under reversed polarization. 相似文献
3.
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
4.
S. Bonnefont B. Messant M. Boutillier O. Gauthier-Lafaye F. Lozes-Dupuy A. Martinez V. Sallet K. Merghem L. Ferlazzo J. C. Harmand A. Ramdane J. G. Provost B. Dagens J. Landreau O. Le Gouezigou X. Marie 《Optical and Quantum Electronics》2006,38(4-6):313-324
Optimization and characterization of multiple InGaAsN/GaAs quantum-well laser diodes for high frequency operation are reported.
From the modelling of the dilute nitride quantum well, we investigate how to design the structure to achieve a high frequency
operation. The gain characteristics are optimized by incorporating the minimum amount of nitrogen in the well to obtain the
emission at 1.3 μm with a low transparency density and a high differential gain. We show that the number of wells must be
adjusted to three to benefit of the best compromise between the threshold current and the differential gain. The effects of
the cavity losses on the dynamic characteristics are evaluated and demonstrate the interest for high cavity losses to reach
high relaxation frequency despite a lower characteristic temperature. An optimized structure has been realized and exhibits
an emission at 1.34 μm with a transparency current density of 642 A/cm2 and a characteristic temperature T0 ~ 80 K. Dynamic properties for ridge devices are evaluated from relative intensity noise measurements and small-signal modulation.
A relaxation frequency as high as 7.4 GHz and a 9.7 GHz small-signal bandwidth are reported. We demonstrate transmission up
to 10 Gb/s at 25°C without penalty and bit error floor. 相似文献
5.
6.
制备了普通的有机量子阱结构,并对结构进行了表征.在此基础上,制备了量子阱结构的白光电致发光器件.在分析了制作工艺对有机量子阱结构特性可能产生的影响之后,为了减少垒、阱界面互扩散效应的影响,提出了有机掺杂量子阱的概念,即垒与阱的母体是相同材料,只是在生长垒层的过程中同时掺入少量发光剂.由于掺杂剂的浓度梯度只有百分之零点几,因此,界面互扩散的影响很小,实际上我们用这种办法制备的有机量子阱器件的亮度、效率均有明显提高.在研究了阱数对器件特性的影响之后,我们发现一般情况下,两个阱是最好的.进一步研究了阱母体材料对有机量子阱器件特性的影响,结果发现,用NPB作母体比Alq作母体更好,这时器件的效率(cd/A)在45~13V工作电压范围内变化不大. 相似文献
7.
The property of hole capture of quantum wells is important in the static properties of lasers above threshold, such as the differential efficiency and light output power. We investigate experimentally the hole capture rate and its influence on the carrier overflow in the optical confinement layers for compressive-strained, tensile-strained and unstrained GaInAs/GaInAsP/InP quantum-well lasers emitting at 1.5 m by measuring the spontaneous emission from the optical confinement layers above threshold. The carrier density in the optical confinement layers increases with current owing to finite hole capture rates. This increase is dependent on well thickness and barrier height determined by the strain. This increase is comparable in the tensile-strained and unstrained lasers with relatively low threshold, while in the compressive-strained laser it is about double that in the other two types. The dependence of this increase on threshold carrier density is also observed, that is the carrier density in the optical confinement layers increases rapidly in high-threshold samples, in particular, in the tensile-strained laser with large hole barrier height. From these results, laser operation with high output power and high efficiency is expected by reducing threshold carrier density in the tensile-strained laser and by increasing well numbers in the compressive-strained laser as long as the inhomogeneous injection between wells is not severe. By fitting measurements with theory, the hole capture time is estimated as 0.1 to 0.25 ps in these strained and unstrained lasers. 相似文献
8.
A low-threshold and high-power oxide-confined 850-nm AlInGaAs strained quantum-well vertical-cavity surface-emitting laser
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A low-threshold and high-power oxide-confined 850-nm AlInGaAs strained quantum-well (QW) vertical-cavity surface-emitting laser (VCSEL) based on an intra-cavity contacted structure is fabricated. A threshold current of 1.5 mA for a 22 μm oxide aperture device is achieved, which corresponds to a threshold current density of 0.395 kA/cm2. The peak output optical power reaches 17.5 mW at an injection current of 30 mA at room temperature under pulsed operation. While under continuous-wave (CW) operation, the maximum power attains 10.5 mW. Such a device demonstrates a high characteristic temperature of 327 K within a temperature range from -12℃ to 96℃ and good reliability under a lifetime test. There is almost no decrease of the optical power when the device operates at a current of 5 mA at room temperature under the CW injection current. 相似文献
9.
Y. Qu J.X. Zhang A. Uddin C.Y. Liu S. Yuan M.C.Y. Chan B. Bo G. Liu H. Jiang 《Applied Physics A: Materials Science & Processing》2006,82(2):305-308
Ridge-waveguide InGaAsN triple-quantum-well strain-compensated lasers grown by metal organic chemical vapor deposition were fabricated with pulsed anodic oxidation. The laser’s output power reached 145 mW in continuous-wave mode at room temperature for a 4-?m -stripe-width laser. Continuous-wave single longitudinal mode operation was maintained at a high injection current level with a wavelength of 1287.3 nm at room temperature. Single longitudinal mode operation at 1317.2 nm was achieved at twice the threshold current at 100 °C. The band gap of InGaAsN in the quantum wells at different temperatures was calculated and compared to the measured temperature-dependent laser wavelength. 相似文献
10.
An optical bandwidth analysis of a quantum-well (16 nm) transistor laser with 150-μm cavity length using a charge control model is reported in order to modify the quantum-well location through the base region. At constant bias current, the simulation shows significant enhancement in optical bandwidth due to moving the quantum well in the direction of collector-base junction. No remarkable resonance peak, limiting factor in laser diodes, is observed during this modification in transistor laser structure. The method can be utilized for transistor laser structure design. 相似文献
11.
An in-dept analysis on the separate confinement heterostructure (SCH) design parameters of 1.5-μm InGaAlAs/InP multiple quantum-well
(MQW) lasers is reported. Theoretical calculations show a drastic enhancement on threshold current and slope efficiency from
step-index SCH (STEP-SCH) to graded-index SCH (GRIN-SCH) design, but the effect ceases beyond a critical number of grading
steps. This finding implies ease of the growth process and reduction in cost. The overall GRIN-SCH’s thickness is found to
exert great influence over the achievable laser’s threshold current and slope efficiency. An average of 27 mA threshold current
reduction and more than 32% of slope efficiency increment were achieved by optimizing the GRIN-SCH thickness. Increasing the
grading energy range of the GRIN-SCH decreases the slope efficiency, but is found to effectively reduce carrier leakage at
elevated temperature leading to a less temperature-sensitive threshold current MQW ridge lasers were fabricated and characterized
out of two laser materials, one with a reference STEP-SCH and another with a proposed optimized GRIN-SCH profile. The laser
with optimised SCH design has shown a 36% reduction in room temperature threshold current as compared to that with the STEP-SCH
design, which is in good agreement to the theoretical simulation. In addition, a record high characteristic temperature (T
0) of 105 K was obtained on the GRIN-SCH laser structure, which is more than three fold increment as compared to the STEP-SCH
design. 相似文献
12.
Room-temperature (RT) continuous-wave (CW) operation of the 405-nm ridge-waveguide (RW) InGaN/GaN quantum-well diode lasers
equipped with the n-type GaN substrate and two contacts on both sides of the structure has been investigated with the aid
of the comprehensive self-consistent simulation model. As expected, the mounting configuration (p-side up or down) has been
found to have a crucial impact on the diode laser performance. For the RT CW threshold operation of the otherwise identical
diode laser, the p-side up RW laser exhibits as high as nearly 68°C maximal active-region temperature increase whereas an
analogous increase for the p-side down laser was equal to only 24°C. Our simulation reveals that the lowest room-temperature
lasing threshold may be expected for relatively narrow and deep ridges. For the structure under consideration, the lowest
threshold current density of 5.75 kA/cm2 has been determined for the 2.2-μm ridge width and the 400-nm etching depth. Then, the active-region temperature increase
was as low as only 24 K over RT. For wider 5-μm ridge, this increase is twice higher. An impact of etching depth is more essential
for narrower ridges. Quite high values (between 120 and 140 K) of the characteristic parameter T0 convince very good thermal properties of the above laser. 相似文献
13.
Sheng-Horng Yen Bo-Jean Chen Yen-Kuang Kuo 《Optical and Quantum Electronics》2006,38(12-14):1029-1037
Optical properties of the InGaN violet and ultraviolet multiple-quantum-well laser diodes are numerically studied with a self-consistent simulation program. Specifically, the performance of the laser diodes of various active region structures, operating in a spectral range from 385 to 410 nm, are investigated and compared. The simulation results indicate that the double-quantum-well laser structure with a peak emission wavelength of 385–410 nm has the lowest threshold current. The characteristic temperature of the single-quantum-well laser structure increases as the peak emission wavelength increases. The triple-quantum-well structure has the largest characteristic temperature when the peak emission wavelength is shorter than 405 nm, while the double-quantum-well structure possesses the largest characteristic temperature when the peak emission wavelength is larger than 405 nm. 相似文献
14.
DEBAISIEUX G. HERVE´-GRUYER G. FILOCHE M. BOUCHOULE S. PALMIER J. F. 《Optical and Quantum Electronics》1997,29(6):651-660
This paper presents a self-consistent 1-D multiquantum-well laser simulation in which, for the first time, the Schro¨dinger
equation is solved over the whole quantum-well zone, taking into account well-to-well coupling. The computed light-intensity
curve is compared with experimental results for an InGaAs/InGaAsP multiquantum-well laser and also with simplified models.
The quantum calculation has an important influence on the carrier density profile in the active region. This results in a
significant difference in the estimation of the threshold current with respect to other simplified models.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
采用金属有机物化学气相淀积(MOCVD)方法生长了InGaAs/GaAs应变量子阱,通过优化生长条件和采用应变缓冲层结构获得量子阱,将该量子阱结构应用于1 054 nm激光器的制备。经测试该器件具有9 mA低阈值电流和0.4 W/A较高的单面斜率效率,在驱动电流为50 mA时测得该应变量子阱光谱半宽为1.6nm,发射波长为1 054 nm。实验表明:通过优化工艺条件和采用应变缓冲层等手段,改善了应变量子阱质量,该结果应用于1 054 nm激光器的制备,取得了较好的结果。 相似文献
16.
L. A. Kulakova A. V. Lutetskiy 《Bulletin of the Russian Academy of Sciences: Physics》2018,82(5):481-486
The effect acoustic strains of an active medium have on the spectral characteristics of the emission of quantum-well and quantum-dot heterolasers is studied experimentally and theoretically. Results obtained earlier for the effect on the emission spectrum are briefly reviewed. The polarization effects recently observed in laser structures of different compositions at various levels of the operating current above its threshold value are analyzed in detail. 相似文献
17.
Asymmetric multiple-quantum-well laser diodes with wide and flat gain spectra were designed, fabricated, and analyzed. The active layer was composed of three 10-nm, one 8-nm, and two 6-nm 0.5% compressive strained wells and four 10-nm and one 5-nm 0.4% tensile strained barrier layer. Measured spectra of antireflection-coated ridge waveguide laser diodes with such quantum-well structures have shown that -1-dB spectral gain bandwidth can be as large as 90 nm. 相似文献
18.
L. E. Vorob’ev D. A. Firsov V. A. Shalygin V. N. Tulupenko Yu. M. Shernyakov N. N. Ledentsov V. M. Ustinov Zh. I. Alferov 《JETP Letters》1998,67(4):275-279
The spontaneous emission of far-infrared radiation (λ≅10–20 μm) from diode structures with vertically coupled InGaAs/AlGaAs
quantum dots is observed. This emission is due both to transitions of holes and electrons between size-quantization levels
in quantum dots and to transitions from the continuum to a level in a quantum dot. It is observed only when accompanied by
lasing at short wavelengths (λ≅0.94 μm) and, like the short-wavelength emission, it exhibits a current threshold. The spontaneous
emission of long-wavelength radiation is also observed in InGaAs/GaAs quantum-well laser structures. This radiation is approximately
an order of magnitude weaker than that from quantum-dot structures, and it has no current threshold.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 4, 256–260 (25 February 1998) 相似文献
19.
Multiple-quantum well InGaAs laser structures emitting at 2 \(\upmu \) m with different barriers are modeled using commercial software that combines gain calculation with 2-D simulations of carrier transport and waveguiding. The model is calibrated using experimental results. The simulated results show a non-uniform distribution of carriers in different quantum wells with InGaAlAs barriers which affects their contribution to the gain. The carrier uniformity and a reduction in threshold current density are observed when we use an InGaAs barrier material. The quantum well number was varied from 2 to 4 in both structures and a comparison of the threshold current and its variation with temperature were investigated. 相似文献
20.
Yu. A. Aleshchenko V. V. Kapaev M. V. Kochiev Yu. G. Sadof’ev V. A. Tsvetkov 《JETP Letters》2014,99(4):182-186
Photoluminescence kinetics in multiperiod GaAs/AlGaAs quantum-well structures with asymmetric barrier heights has been investigated. Owing to the barrier asymmetry, a time constant of nonradiative recombination between the laser subbands of 9 ps has been achieved, which is record long for unipolar lasers and exceeds the nonradiative relaxation time constant of the lower laser subband. This provides population inversion in the system. Efficient suppression of an unwanted cascade transition between the laser subbands via quasi-continuum states has been demonstrated. 相似文献