トップ QNERCとは 運営委員会 研究グループ 研究施設 研究室 出版物 討論会 講演 ニュースレター 旧職員 関連リンク 連絡先	トップ > 研究室 > 荒井　研究室 次世代光通信システムのための要素技術と高性能・高機能量子効果光デバイスの開拓 荒井　研究室 http://www.pe.titech.ac.jp/AraiLab/index-e.html 研究目的 The purpose of this study is to develop high-performance / functional quantum-effect photonic devices for future light wave communications, and extremely low-damage processing of ultra-fine structures as well as technologies for integration of functional photonic devices. 研究分野 Optical and quantum electronics, Optoelectronics, Light wave communications, Semiconductor photonic devices 研究テーマ 1. Ultra-low-damage fabrication technologies for ultra-fine structures We are developing ultra-low-damage fabrication technologies of ultra-fine structures for high-performance photonic devices utilizing the quantum-size effect. As a candidate the combination of a direct patterning by an electron-beam-exposure (EBX) and a reactive-ion-etching (RIE) with CH4/H2 gas mixture followed by an embedding growth by an organo-metallic vapor-phase-epitaxy (OMVPE) has been employed to realize fine GaInAsP/InP 5-layered quantum-wire (width: 23nm, period: 80nm) lasers (Fig. 1). Fig 1: Cross sectional SEM image of 4-layered quantum-wire laser. 2. Long wavelength semiconductor lasers for future light wave communications Taking an advantage of the low-damage fabrication process, a record low threshold current (0.7mA) as well as a record low threshold current density (94A/cm2) of 1.55mm GaInAsP/InP distributed feedback (DFB) lasers was achieved by using wire like active regions. No degradations after 1-year RT-CW aging test were observed (Fig. 2). Fig 2: Cross sectional SEM image and L-I characteristics of DFB lasers with wire like active regions. Membrane BH-DFB lasers consisting of wire like active regions buried in 140nm thick semiconductor were fabricated. A low threshold RT-CW operation with a stable single-mode property under optical pumping (1.5mW: corresponding threshold current 27mA) was achieved (Fig. 3). Low threshold current (2.8mA) operation of distributed reflector (DR) lasers consisting of vertical grating (VG) DFB and DBR regions were realized (Fig. 4). We are aiming at a breakthrough in processing technologies to realize high-performance/functional photonic devices as well as to propose novel photonic devices based on quantum-effects. Fig 3: Cross sectional SEM image and L-I characteristics of DFB lasers with wire like active regions. Fig. 4 : Structure and L-I characteristics of a DR laser with vertical-grating DFB and DBR regions.