High-performance 1.55-Μm wavelength GaInAsP-InPdistributed-feedback lasers with wirelike active regions

摘要

High-performance 1.55-Μm wavelength GaInAsP-InP stronglynindex-coupled and gain-matched distributed-feedback (DFB) lasers withnperiodic wirelike active regions mere fabricated by electron beamnlithography, CH4/H2-reactive ion etching, andnorganometallic vapor-phase epitaxial regrowth, whose index-couplingncoefficient was more than 300 cm-1. In order to design lasersnfor low threshold current operation, threshold current dependences onnthe number of quantum wells and the wire width mere investigated bothntheoretically and experimentally. A record low threshold current densitynof 94 A/cm2 among 1.55-Μm DFB lasers was successfullynobtained for a stripe width of 19.5 Μm and a cavity length of 600nΜm. Moreover, a record low threshold current of 0.7 mA was alsonrealized at room temperature under CW condition for a 2.3-Μm-widenburied heterostructure with a 200-Μm-long cavity. Finally, wenconfirmed stable single-mode operation due to a gain-matching effectnbetween the standing-wave profile and the wirelike active region