Title :
Theory and experiment of high-speed cross-gain modulation in semiconductor lasers
Author :
Jin, X. ; Keating, T. ; Chuang, S.L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Univ., Urbana, IL, USA
Abstract :
We present theory and experiment for the high-speed modulation response of a quantum-well (QW) laser in the presence of an external microwave modulated optical pump in the gain region. The model includes the effects of pump-induced stimulated recombination and cross-gain saturation. Expressions for the small-signal modulation response of the test laser under gain modulation are derived. We also present experimental results using a multiple-QW InGaAlAs Fabry-Perot (FP) laser at 1.552 /spl mu/m as the test laser and an external pump by a 1.542 /spl mu/m DFB laser. Comparison between electrical modulation and optical cross-gain modulation (XGM) of the test laser is also presented, which shows improvement of the modulation bandwidth by optical XGM. Our data show a reduction of carrier lifetime with increasing optical pumping, a shift of the test-laser threshold current, a change in the K factor, and a variation of the relaxation frequency with different pump powers. The experimental results agree very well with the theoretical results.
Keywords :
Fabry-Perot resonators; III-V semiconductors; aluminium compounds; carrier lifetime; distributed feedback lasers; gallium arsenide; high-speed optical techniques; indium compounds; laser beams; laser feedback; optical modulation; optical pumping; optical saturation; quantum well lasers; 1.542 mum; 1.552 mum; DFB laser; InGaAlAs; K factor; carrier lifetime; cross-gain saturation; electrical modulation; external microwave modulated optical pump; external pump; gain modulation; gain region; high-speed cross-gain modulation; high-speed modulation response; modulation bandwidt; multiple quantum well Fabry-Perot laser; optical cross-gain modulation; optical pumping; pump powers; pump-induced stimulated recombination; quantum-well laser; relaxation frequency; semiconductor lasers; small-signal modulation response; test laser; test-laser threshold current; High speed optical techniques; Laser excitation; Laser modes; Laser theory; Masers; Optical modulation; Optical pumping; Optical saturation; Pump lasers; Testing;
Journal_Title :
Quantum Electronics, IEEE Journal of
