Low threshold current operation of 1.3 /spl mu/m narrow beam divergence tapered-thickness waveguide lasers

摘要

Low threshold current operation of 1.3 /spl mu/m narrow beam divergence tapered-thickness waveguide lasers is demonstrated by high-reflection coating to both facets and optimising the gain region length. A 320 /spl mu/m long laser which consisted of 120 /spl mu/m long gain region and 200 /spl mu/m lone tapered waveguide showed low threshold currents of 3.2 mA at 25/spl deg/C and 10.5 mA at 85/spl deg/C as well as FWHM beam divergence of >10/spl deg/. These threshold currents are the lowest data ever reported among spot-size transformer integrated lasers, to the authors' knowledge.