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Development of Novel Distributed Feedback Semiconductor Lasers with Reflection Insensitivity and Very Low Chirping Property

具有反射不敏感和极低啁啾特性的新型分布式反馈半导体激光器的开发

基本信息

批准号：
01850014
负责人：
TADA Kunio
金额：
$ 8.7万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B).
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

1. Purely Gain-Coupled Distributed Feedback (DFB) Laser A novel DFB laser structure has been proposed, where pure gain coupling without index coupling is in principle brought about. We realized it by utilizing a special growth kinetics of organo-metallic vapor phase epitaxy, and achieved room-temperature continuous-wave operation with very low threshold current of 17mA. We have also showed theoretically and experimentally that, in the gain-coupled DFB laser, the oscillation mode is uniquely defined irrespective of facet phases, and there fore that very high single mode yield is obtainable even with as-cleaved end facets.2. External Reflection Insensitivity in Gain-Coupled DFB Lasers Dependence of intensity noise on external reflection of the above laser has been measured and compared with that of the conventional DFB laser. If the amount of reflection was less than 1%, the excess noise induced by the reflection was 10-20dB less in the case of remote reflection, and virtually no increas … More e in noise was observed in the case of adjacent reflection.3. Ultralow Chirping, Single Mode Optical Short Pulse Generation in Gain-Coupled DFB Lasers We have tried gain-switching short optical pulse generation experiment in the above laser using electrical pulses, and obtained an optical pulse of 16ps FWHM. Time-averaged spectra of the optical pulse have been measured and surprisingly found to be of single mode with 0.12nm FWHM. The linewidth enhancement factor estimated from these values is as small as 1.6.4. Low Chirping DFB Lasers with Distributed Electrode and Modulated Stripe Width Structures It has been shown through numerical simulation that, by using the above structures proposed here, the oscillation wavelength shift resulting from the longitudinal spatial hole burning can completely be eliminated, and that the chirping accompanying the relaxation oscillation can considerably be reduced.5. Monolithic Integration of a DFB Laser and a Modulator / Amplifier for Low Chirping Operation An alternative approach to realize low chirping modulation has been tried by integrating a traveling wave optical amplifier / modulator. We pointed out the usefulness of angled facets formed by reactive ion etching for reduction of optical cross-talk. The fabricated integrated device exhibited performances good enough for practical use, such as 20mA threshold and 10dB optical gain. Less

1.纯增益耦合分布反馈(DFB)激光器提出了一种新的DFB激光器结构，原理上实现了纯增益耦合而不是折射率耦合。我们利用有机金属气相外延特殊的生长动力学实现了这一点，并实现了阈值电流为17 mA的室温连续工作。我们还从理论和实验上证明，在增益耦合的DFB激光器中，振荡模式是唯一定义的，而不受小面相位的影响，因此即使在解理端面的情况下也可以获得很高的单模产额。测量了增益耦合DFB激光器的外反射不灵敏特性，并与传统的DFB激光器进行了比较。当反射量小于1%时，由反射引起的过量噪声在远反射的情况下减少了10-20db，并且几乎没有增加…在相邻反射的情况下，可以观察到更多的噪声。在增益耦合DFB激光器中产生超低啁啾单模光学短脉冲我们用电脉冲在上述激光器上进行了增益开关短脉冲产生实验，获得了16ps半高宽的光脉冲。测量了光脉冲的时间平均光谱，令人惊讶地发现它是单模的，半高宽为0.12 nm。由这些值估计的线宽增强因子最小为1.6.4。分布电极调制条带结构的低啁啾DFB激光器的数值模拟结果表明，采用上述结构可以完全消除纵向空间烧孔引起的振荡波长漂移，并能显著降低弛豫振荡引起的啁啾。用于低啁啾运转的DFB激光器和调制器/放大器的单片集成尝试了一种通过集成行波光放大器/调制器来实现低啁啾调制的替代方法。指出了反应离子刻蚀形成的有角度的刻面对减小光学串扰的作用。所制作的集成器件具有良好的实际应用性能，如阈值为20 mA，光增益为10dB.较少