Ultrafast gain and index dynamics of quantum dash structures emitting at 1.55μm

The authors systematically characterize the ultrafast gain and index recovery of a quantum dash semiconductor optical amplifier after it has amplified a strong femtosecond pulse. The results show a recovery dominated by a fast time constant of 1.4ps with an ultimate recovery taking place on a 150ps time scale. The results are distinctly different from the recovery of quantum dot amplifiers and reflect the special density of states of the quantum-wire-like dashes.

[1]  D. Bimberg,et al.  Ultrafast gain dynamics in InAs-InGaAs quantum-dot amplifiers , 2000, IEEE Photonics Technology Letters.

[2]  A. Forchel,et al.  Long-wavelength InP-based quantum-dash lasers , 2002, IEEE Photonics Technology Letters.

[3]  Peter Michael Smowton,et al.  Experimental investigation of the effect of wetting-layer states on the gain–current characteristic of quantum-dot lasers , 2002 .

[4]  A. Stintz,et al.  Room-temperature operation of InAs quantum-dash lasers on InP [001] , 2001, IEEE Photonics Technology Letters.

[5]  D. Birkedal,et al.  Ultrafast gain dynamics in quantum-dot amplifiers: theoretical analysis and experimental investigations , 2005, IEEE Journal of Quantum Electronics.

[6]  Y. Arakawa,et al.  Recent progress in self-assembled quantum-dot optical devices for optical telecommunication: temperature-insensitive 10 Gb s−1 directly modulated lasers and 40 Gb s−1 signal-regenerative amplifiers , 2005, 2006 Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference.

[7]  J. Mørk,et al.  One- and two-phonon capture processes in quantum dots , 2002 .

[8]  Michel Calligaro,et al.  Multiple wavelength amplification in wide band high power 1550 nm quantum dash optical amplifier , 2004 .

[9]  T. W. Berg,et al.  Ultrafast gain recovery and modulation limitations in self-assembled quantum-dot devices , 2001, IEEE Photonics Technology Letters.

[10]  Mikhail V. Maximov,et al.  Tuning quantum dot properties by activated phase separation of an InGa(Al)As alloy grown on InAs stressors , 2000 .

[11]  Dieter Bimberg,et al.  Quantum dots: lasers and amplifiers , 2003, Microelectron. J..

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

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

[14]  Hanan Dery,et al.  On the nature of quantum dash structures , 2004 .

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