Spectral hole-burning and carrier-heating dynamics in InGaAs quantum-dot amplifiers

The ultrafast gain and index dynamics in a set of InAs-InGaAs-GaAs quantum-dot (QD) amplifiers are measured at room temperature with femtosecond resolution. The role of spectral hole-burning (SHB) and carrier heating (CH) in the recovery of gain compression is investigated in detail. An ultrafast recovery of the spectral hole within /spl sim/100 fs is measured, comparable to bulk and quantum-well amplifiers, which is contradicting a carrier relaxation bottleneck in electrically pumped QD devices. The CH dynamics in the QD is quantitatively compared with results on an InGaAsP bulk amplifier. Reduced CH for both gain and refractive index dynamics of the QD devices is found, which is a promising prerequisite for high-speed applications. This reduction is attributed to reduced free-carrier absorption-induced heating caused by the small carrier density necessary to provide amplification in these low-dimensional systems.

[1]  Andreas Stintz,et al.  Extremely low room-temperature threshold current density diode lasers using InAs dots in In/sub 0.15/Ga/sub 0.85/As quantum well , 1999 .

[2]  Mitsuru Sugawara,et al.  Light emission spectra of columnar-shaped self-assembled InGaAs/GaAs quantum-dot lasers: Effect of homogeneous broadening of the optical gain on lasing characteristics , 1999 .

[3]  Dieter Bimberg,et al.  Room-temperature continuous-wave lasing from stacked InAs/GaAs quantum dots grown by metalorganic chemical vapor deposition , 1997 .

[4]  Ali M. Darwish,et al.  Subpicosecond gain and index nonlinearities in InGaAsP diode lasers , 1994 .

[5]  N. Yokoyama,et al.  1.3-μm CW lasing of InGaAs-GaAs quantum dots at room temperature with a threshold current of 8 mA , 1999, IEEE Photonics Technology Letters.

[6]  Dieter Bimberg,et al.  ELECTRON ESCAPE FROM INAS QUANTUM DOTS , 1999 .

[7]  J. Laskar,et al.  Enhanced modulation bandwidth (20 GHz) of In/sub 0.4/Ga/sub 0.6/As-GaAs self-organized quantum-dot lasers at cryogenic temperatures: role of carrier relaxation and differential gain , 1998, IEEE Photonics Technology Letters.

[8]  rk,et al.  Carrier heating in InGaAsP laser amplifiers due to two-photon absorption , 1994 .

[9]  D. Bimberg,et al.  Study of high frequency response of self-organised stacked quantum dot lasers at room temperature , 1997 .

[10]  Jesper Mørk,et al.  Theory of heterodyne pump–probe experiments with femtosecond pulses , 1996 .

[11]  Egorov,et al.  Direct formation of vertically coupled quantum dots in Stranski-Krastanow growth. , 1996, Physical review. B, Condensed matter.

[12]  Jesper Mørk,et al.  Dephasing in InAs/GaAs quantum dots , 1999 .

[13]  Johann Peter Reithmaier,et al.  High-performance GaInAs/GaAs quantum-dot lasers based on a single active layer , 1999 .

[14]  Weidong Yang,et al.  Effect of carrier emission and retrapping on luminescence time decays in InAs/GaAs quantum dots , 1997 .

[15]  Jesper Mørk,et al.  Theory of the ultrafast optical response of active semiconductor waveguides , 1996 .

[16]  K. Nishi,et al.  A narrow photoluminescence linewidth of 21 meV at 1.35 μm from strain-reduced InAs quantum dots covered by In0.2Ga0.8As grown on GaAs substrates , 1999 .

[17]  Jasprit Singh,et al.  Rapid carrier relaxation in In 0.4 Ga 0.6 A s / G a A s quantum dots characterized by differential transmission spectroscopy , 1998 .

[18]  Nikolai N. Ledentsov,et al.  InGaAs-GaAs quantum-dot lasers , 1997 .

[19]  S. Weisser,et al.  Differential gain, refractive index, and linewidth enhancement factor in high-speed GaAs-based MQW lasers: influence of strain and p-doping , 1994, IEEE Photonics Technology Letters.

[20]  Jesper Mørk,et al.  Heterodyne pump-probe and four-wave mixing in semiconductor optical amplifiers using balanced lock-in detection , 1999 .

[21]  D. Deppe,et al.  1.3 μm room-temperature GaAs-based quantum-dot laser , 1998 .

[22]  J. Hvam,et al.  Time-resolved four-wave mixing in InAs/InGaAs quantum-dot amplifiers under electrical injection , 2000 .

[23]  Mycielski,et al.  Recombination-induced heating of free carriers in a semiconductor. , 1985, Physical review. B, Condensed matter.

[24]  Mikhail V. Maximov,et al.  Long-wavelength lasing from multiply stacked InAs/InGaAs quantum dots on GaAs substrates , 1999 .

[25]  Antonio Mecozzi,et al.  Spectral effects in short pulse pump‐probe measurements , 1996 .

[26]  James L. Merz,et al.  Excited-state radiative lifetimes in self-assembled quantum dots obtained from state-filling spectroscopy , 1999 .

[27]  J. Fujimoto,et al.  Femtosecond investigations of spectral hole burning in semiconductor lasers , 1995 .

[28]  G. Bastard,et al.  Phonon-assisted capture and intradot Auger relaxation in quantum dots , 1999 .

[29]  D. Deppe,et al.  InGaAs/GaAs quantum dot lasers , 1998, Conference Proceedings. LEOS'98. 11th Annual Meeting. IEEE Lasers and Electro-Optics Society 1998 Annual Meeting (Cat. No.98CH36243).

[30]  B Golubovic,et al.  Heterodyne nondegenerate pump-probe measurement technique for guided-wave devices. , 1995, Optics letters.

[31]  Nikolai N. Ledentsov,et al.  Energy relaxation by multiphonon processes in InAs/GaAs quantum dots , 1997 .

[32]  J. Mark,et al.  Subpicosecond gain dynamics in InGaAsP optical amplifiers: Experiment and theory , 1992 .

[33]  Erich P. Ippen,et al.  Ultrafast refractive index dynamics in AlGaAs diode laser amplifiers , 1991 .

[34]  Dieter Bimberg,et al.  Gain and Threshold of Quantum Dot Lasers: Theory and Comparison to Experiments , 1997 .

[35]  W. S. Hobson,et al.  Room-temperature 1.3 mum emission from InAs quantum dots grown by metal organic chemical vapor deposition , 1999 .

[36]  J. M. Rorison,et al.  Quantum Dot Heterostructures , 2000 .

[37]  Nikolai N. Ledentsov,et al.  1.3 [micro sign]m GaAs-based laser using quantum dots obtained by activated spinodal decomposition , 1999 .

[38]  K L Hall,et al.  Heterodyne pump - probe technique for time-domain studies of optical nonlinearities in waveguides. , 1992, Optics letters.

[39]  Hiroshi Ishikawa,et al.  Lasing with low threshold current and high output power from columnar-shaped InAs/GaAs quantum dots , 1998 .