Title :
InGaAs-GaAs quantum-dot lasers
Author :
Bimberg, D. ; Kirstaedter, N. ; Ledentsov, N.N. ; Alferov, Zh.I. ; Kop´ev, P.S. ; Ustinov, V.M.
Author_Institution :
Tech. Univ. Berlin, Germany
fDate :
4/1/1997 12:00:00 AM
Abstract :
Quantum-dot (QD) lasers provide superior lasing characteristics compared to quantum-well (QW) and QW wire lasers due to their delta like density of states. Record threshold current densities of 40 A·cm -2 at 77 K and of 62 A·cm-2 at 300 K are obtained while a characteristic temperature of 385 K is maintained up to 300 K. The internal quantum efficiency approaches values of ~80 %. Currently, operating QD lasers show broad-gain spectra with full-width at half-maximum (FWHM) up to ~50 meV, ultrahigh material gain of ~105 cm-1, differential gain of ~10-13 cm2 and strong nonlinear gain effects with a gain compression coefficient of ~10-16 cm3. The modulation bandwidth is limited by nonlinear gain effects but can be increased by careful choice of the energy difference between QD and barrier states. The linewidth enhancement factor is ~0.5. The InGaAs-GaAs QD emission can be tuned between 0.95 μm and 1.37 μm at 300 K
Keywords :
III-V semiconductors; current density; electronic density of states; gallium arsenide; indium compounds; laser transitions; laser tuning; leakage currents; optical losses; quantum well lasers; semiconductor quantum dots; spectral line breadth; 0.95 to 1.37 mum; 300 K; 385 K; 50 meV; 77 K; 80 percent; FWHM; InGaAs-GaAs; InGaAs-GaAs QD emission; InGaAs-GaAs quantum-dot lasers; barrier states; broad-gain spectra; characteristic temperature; delta like density of states; differential gain; full-width at half-maximum; gain compression coefficient; internal quantum efficiency; lasing characteristics; linewidth enhancement factor; modulation bandwidth; strong nonlinear gain effects; threshold current densities; tuning; ultrahigh material gain; Chemical lasers; Fiber lasers; Laser beam cutting; Quantum dot lasers; Quantum dots; Quantum well lasers; Semiconductor laser arrays; Semiconductor lasers; Temperature; Threshold current;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/2944.605656