Title :
Low-threshold-current-density 1.5 mu m lasers using compressively strained InGaAsP quantum wells
Author :
Osinski, J.S. ; Zou, Y. ; Grodzinski, P. ; Mathur, A. ; Dapkus, P.D.
Author_Institution :
Dept. of Electr. Eng., Univ. of Southern California, Los Angeles, CA, USA
Abstract :
A low-threshold current density (J/sub th/) of 140 A/cm/sup 2/ for broad-area 1.5- mu m semiconductor lasers with uncoated facets is demonstrated at a cavity length of 3.5 mm. This was achieved by the use of a single InGaAsP quantum well (QW) of 1.8% compressive strain inside a step-graded InGaAsP waveguide region. Low-cavity losses of 3.5 cm/sup -1/ and a relatively wide quantum well as compared to InGaAs wells of equivalent strain contribute to this high performance. Double QW devices of 2 mm length showed threshold current densities of 241 A/cm/sup 2/. Quaternary single and double QWs of similar width but only 0. 9% strain gave slightly higher threshold current density values, but allowed growth of a 4 QW structure with a J/sub th/ of 324 A/cm/sup 2/ at L=1.5 mm.<>
Keywords :
III-V semiconductors; current density; gallium arsenide; indium compounds; laser transitions; semiconductor junction lasers; 1.5 micron; 2 mm; 3.5 mm; III-V semiconductor; MQW; SQW; broad area lasers; cavity length; compressively strained InGaAsP quantum wells; double QW; high performance; low cavity losses; low-threshold current density; quaternary single QW; step-graded InGaAsP waveguide region; uncoated facets; Capacitive sensors; Indium gallium arsenide; Indium phosphide; Optical design; Optical materials; Quantum well lasers; Semiconductor lasers; Strain measurement; Threshold current; Waveguide lasers;
Journal_Title :
Photonics Technology Letters, IEEE
