Research of Ultra-High-Speed Optical Devices Using Multi Dimensional Quantum-Well Structure

多维量子阱结构，如量子线和量子盒，由于其材料性质不同于传统的大块晶体，有望实现高速工作。本研究的主要目的是发展多维量子阱结构的制备技术，并将其应用于超大容量光通信器件。通过对激光器阈值的结构依赖性和光开关/调制器的插入损耗的精确分析，从理论上找到了激光器和多维量子阱结构光开关/调制器的最佳器件结构，并首次在77K用脉冲电流注入的方式在GaInAs/GaInAsP/InP量子线激光器中获得了激光作用，该激光器具有10 nm厚30 nm宽的导线。首次在室温下采用两步OMVPE生长和湿法化学腐蚀制备了具有线状有源区的GaInAs/GaInAsP/InP多量子膜激光器，通过在氢气气氛中预热工艺和在GaInAsP光学限制层重新生长之前生长薄的InP覆盖层，大大降低了激光器的阈值电流密度。该结构在电场作用下具有较大的折射率变化(-4%)和较低的光吸收。这一结果表明，多维量子阱结构适用于高性能光开关/调制器。

Multidimensional quantum-well structures, such as quantum wire and quantum box, are expected to operate with high speed due to their material properties different from conventional bulk crystals. The main purpose of this research is the development of fabrication technique of multidimensional quantum well structures and the application of these structures to devices for ultra-high capacity optical communication. Results obtained are summarized as follows.Optimal device structures were found theoretically for laser and optical switch/modulator with multidimensional quantum well structures by analyzing the structure dependence of the laser threshold and the insertion loss of optical switch/modulator precisely.Lasing action was obtained for the first time at 77K with pulsed current injection in GaInAs/GaInAsP/InP quantum-wire laser with 10nm-thick 30nm-wide wires fabricated by newly developed nanometer fabrication technology viz. Electron beam lithography for pattern writing, wet chemical etching and OMVPE regrowth for embedding process.GaInAs/GaInAsP/InP multi-quantum-film lasers with wire-like active region, Which were fabricated by two step OMVPE growth and wet chemical etching, operated at room temperature for the first time, An increase in the threshold current density in such lasers was drastically reduced by using a preheating process in hydrogen atmosphere and a thin InP covering layer growth prior to the regrowth of a GaInAsP optical confinement layer.A GaInAsP/InP quantum wire structure was fabricated by using a high vacuum electron-cyclotron-resonance reactive-ion-beam-etching system with very low acceleration voltage. Large refractive index variation (-4%) and low optical absorption under electric field application was observed in this structuure. This result indicates that multidimensional quantum well structures are suitable for high performance optical switches/modulators.