共查询到20条相似文献,搜索用时 171 毫秒
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取样光栅分布反馈激光器阵列器件研究 总被引:2,自引:1,他引:1
采用了一种基于取样光栅原理制作多通道增益-折射率耦合型光栅的方法,成功制作了8波长分布反馈(DFB)激光器阵列,阵列中各激光器的阈值电流为30~40 mA,注入电流为100 mA时的平均输出光功率为10mW,阵列器件实现了波长的可选择性激射,相邻激光器间的频率间距为200 GHz,验证了用取样光栅方法制作DFB激光器阵列的可行性。 相似文献
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基于包含增益饱和项的半导体激光器速率方程,分析了增益饱和因子和寄生参数对DFB激光器的动态特性的影响.建立了激光器用于数值计算的Simulink模型,对激光器的调制响应进行了数值分析;结合电子电路的特点,建立了一种考虑寄生参量的小信号等效电路模型,该模型将速率方程表征为由线性电路元件组成的电路模型;采用Matlab和PSpice两种软件模拟了该激光器的调制响应.结果表明张弛振荡频率和调制带宽随偏置电流的增加而增加,而增益饱和因子和寄生参数的存在使谐振频率衰减和带宽降低,同时也证明了所建模型的准确性和适用性.为改善DFB激光器的动态特性及优化设计器件结构参数提供了理论依据. 相似文献
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Cao H.L. Luo Y. Nakano Y. Tada K. Dobashi M. Hosomatsu H. 《Photonics Technology Letters, IEEE》1992,4(10):1099-1102
Grating duty factor strongly affects the performance of gain-coupled (GC) distributed feedback (DFB) laser diodes with an absorptive grating. Through numerical analysis the authors have found an optimum value in the duty factor for their low threshold operation. The minimum threshold gain achievable at this optimum duty factor is found to be almost independent of the order of the grating. According to this prediction, the authors have fabricated GaAlAs/GaAs GC DFB lasers with a third-order absorptive grating where the grating duty factor has been made close to the theoretical optimum value. In 200-μm-long devices with both facets as-cleaved, low CW threshold current of 25 mA, external efficiency of 0.5 mW/mA, and SMSR as high as 45 dB have been obtained, which is qualitatively consistent with the analysis. High yield of single mode oscillation seems to be the result of the gain coupling 相似文献
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S.W. Park J.H. Han Y.T. Han S.S. Park B.Y. Yoon B.K. Kim H.K. Sung J.I. Song 《Photonics Technology Letters, IEEE》2006,18(20):2138-2140
We demonstrate a two-step lateral tapered 1.55-/spl mu/m spot-size converter distributed feedback laser diode (SSC DFB LD) having slope efficiencies as high as 0.457 and 0.319 mW/mA measured at 25 /spl deg/C and 85 /spl deg/C, respectively. The SSC DFB LD fabricated by using a nonselective grating process has a double core waveguide structure including a planar buried heterostructure type active waveguide and a ridge type passive waveguide. The fabricated SSC DFB LD operates at 1.553-/spl mu/m wavelength and shows a far-field pattern in horizontal and vertical directions of 7.3/spl deg/ and 11.6/spl deg/, respectively. 相似文献
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The effects of radiation mode on the oscillating properties of distributed feedback (DFB) lasers with second-order corrugations are analyzed for designing a new type of DFB laser. A formulation based on the transfer matrix technique is applied to calculating Streifer's ζ-terms added to the coupled-wave equations. These terms represent the effects of radiation and evanescent modes. This formulation greatly simplifies the analysis of distributed resonance along multilayered waveguide structures with arbitrary-shaped second-order corrugations. The effects of vertical resonance are also incorporated into the formulation. Various types of DFB lasers with phase-shifted second-order corrugations are analyzed using this method. It is found that the phase shift and the blaze of the corrugations greatly affect the longitudinal mode selectivity. A new phase-shift DFB laser structure with two complementary blazing regions connected at the shift is proposed. It is demonstrated that this structure has small radiation loss resulting in low-threshold performance despite employing second-order corrugations 相似文献
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S.W. Park C.K. Moon D.Y. Kim Y.K. Kim J.I. Song 《Photonics Technology Letters, IEEE》2004,16(3):732-734
We demonstrate a two-step laterally tapered 1.55-/spl mu/m spot size converter distributed feedback laser diode (SSC DFB LD) having a planar buried heterostructure-type active waveguide and a ridge-type passive waveguide fabricated by using a nonselective grating process. Unlike conventional SSC DFB LDs, where a selective grating is employed, this SSC DFB LD employed a nonselective grating over the entire device region in order to make its fabrication much simpler than that of the conventional SSC DFB LDs. The two-step laterally tapered SSC is effective in removing an unwanted wavelength peak originating from the SSC section having a multiquantum well and a grating under it. The fabricated SSC DFB LD operates at 1.553-/spl mu/m wavelength and shows a far field pattern in horizontal and vertical directions of 13.4/spl deg/ and 19.5/spl deg/, respectively. 相似文献
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A unified formulation of the spontaneous emission noise in semiconductor DFB (distributed feedback) lasers is presented by using a transfer-matrix approach. Analytical expressions for the noise power per unit frequency bandwidth below threshold and the spontaneous emission rate into the lasing mode are obtained based on the Green's function method. Three DFB laser structures are analyzed: (1) a standard DFB structure with facet reflectivities, (2) a multisection DFB structure composed of n sections which models a phase-shifted DFB laser and a multielectrode (tunable) DFB laser, and (3) a periodic layered DFB structure which models a surface-emitting DFB laser. It is shown that the spontaneous emission noise of a complicated DFB laser structure can be calculated easily by the transfer matrix of each section of the structure and its derivative to frequency 相似文献
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Hillmer H. Grabmaier A. Zhu H.-L. Hansmann S. Burkhard A. 《Lightwave Technology, Journal of》1995,13(9):1905-1912
We have implemented and studied a new type of tunable multiple-section semiconductor distributed feedback (DFB) laser using tailored chirped DFB gratings. Arbitrarily and continuously chirped DFB gratings are defined by bent waveguides on homogeneous grating fields with ultrahigh spatial precision. The mathematical bending functions are optimized in this case to provide enlarged wavelength tuning ranges. We present the results of model calculations, the technological device realization and experimental results of the DFB laser characterization e.g. a tuning range of 5.5 nm without wavelength gaps and high side mode suppression ratio 相似文献
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给出了适于分析DFB激光器稳态特性的数值模型和分析振幅及频率调制响应特性的解析模型.研究了3相移DFB激光器的调制响应特性,并提出了一种能够快速精确得到DFB激光器多个模式解的新方法--矢量牛顿法.该方法将稳定的矢量法与精确的牛顿法结合,保证了求解质量.实践表明该方法非常适合于求解高度非线性方程的多解问题.用此方法,研究了3相移及简单DFB激光器的纵向光子浓度分布,纵模及调制响应特性.结果表明,3相移DFB具有与简单的DFB激光器同样好的调制响应特性,相移的引入在一定程度上抑制了纵向空间烧孔效应,并且有利于DFB激光器的单模输出. 相似文献
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A novel type of longitudinal instability due to spatial hole burning in symmetric semiconductor laser structures (DFB lasers in particular) is examined analytically and numerically. It is shown that, at a certain output power, the gain and refractive index spatial distributions of the lasing mode become unstable. Above this output power, the modal gains and oscillation frequencies change drastically, which often causes multimode operation. A measure of the cavity stability is introduced and derived analytically for a Fabry-Perot and a single phase-shifted DFB laser. Results from numerical simulations of a multiple phase-shifted DFB laser are presented 相似文献
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The oscillation characteristics of separated-electrode distributed feedback (DFB) lasers are analyzed by a numerical approach. In the calculation, coupled-mode equations are used including the carrier-density nonuniformity along the laser axis, which is introduced by the spatial hole burning and/or the nonuniform current injection. When the center section of a DFB laser, with three equally separated electrodes, is more strongly pumped than the side sections, high performance is achieved: the mode stability is maintained in the high-power state, resulting in a narrow linewidth. This is because the spatial hole burning is compensated by the larger current injection into the center region. The wide tunable range is also obtained under this bias condition 相似文献
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Yi Luo Weimin Si Shengzhong Zhang Di Chen Jianhua Wang 《Photonics Technology Letters, IEEE》1994,6(1):17-20
Molecular beam epitaxy (MBE) regrowth on a corrugated surface is improved dramatically using a novel technique by which not only a clean surface can be obtained but also the shape of grating can be precisely controlled. A GaAlAs/GaAs multi-quantum well gain-coupled distributed feedback (DFB) laser with an absorptive grating is fabricated all by MBE for the first time. DFB mode oscillation within a range of at least 80°C is achieved. Stable single longitudinal mode oscillation is maintained up to 20 mW 相似文献