40 GHz small-signal cross-gain modulation in 1.3m quantum dot semiconductor optical amplifiers

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 93, 051110 (2008) and may be found at https://doi.org/10.1063/1.2969060.Small-signal cross-gain modulation of quantum dot based semiconductor optical amplifiers (QD SOAs), having a dot-in-a-well structure, is presented, demonstrating superiority for ultrahigh bit rate wavelength conversion. Optimization of the QD SOA high speed characteristics via bias current and optical pump power is presented and a small-signal 3 dB bandwidth exceeding 40 GHz is demonstrated. The -doped samples investigated here enable small-signal wavelength conversion within a range of 30 nm, limited mainly by the gain bandwidth.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP6/027638/EU/Transparent Ring Interconnection Using Multiwavelngth PHotonic switches/TRIUMPHEC/FP6/500101/EU/Self-Assembled semiconductor Nanostructures for new Devices in photonics and Electronics/SANDI

Two-state semiconductor laser self-mixing velocimetry exploiting coupled quantum-dot emission-states: experiment, simulation and theory

We exploit the coupled emission-states of a single-chip semiconductor InAs/GaAs quantum-dot laser emitting simultaneously on ground-state (λGS = 1245 nm) and excited-state (λES = 1175 nm) to demonstrate coupled-two-state self-mixing velocimetry for a moving diffuse reflector. A 13 Hz-narrow Doppler beat frequency signal at 317 Hz is obtained for a reflector velocity of 3 mm/s, which exemplifies a 66-fold improvement in width as compared to single-wavelength self-mixing velocimetry. Simulation results reveal the physical origin of this signal, the coupling of excited-state and ground-state photons via the carriers, which is unique for quantum-dot lasers and reproduce the experimental results with excellent agreement

Pulse width narrowing due to dual ground state emission in quantum dot passively mode locked lasers

We present an experimental investigation of the emission properties of a multisection InGaAs quantum dot passively mode locked laser under dual waveband emission from the ground state (GS). A mode locking regime directly related to the GS splitting has been depicted. It is related to significant pulse width decrease with increasing injection current under dual peak emission from the GS, leading to generation of pulses with increased peak power with respect to the usual device operation. (C) 2010 American Institute of Physics. [doi:10.1063/1.3432076

Broad Repetition-Rate Tunable Quantum-Dot External-Cavity Passively Mode-Locked Laser with Extremely Narrow Radio Frequency Linewidth

We report on a systematic investigation of a repetition-rate-tunable quantum-dot external-cavity passively mode-locked laser with a quasi-continuous frequency tuning range from 1 GHz to a record-low value of 191 MHz. A nearly constant pulse peak power at the different pulse repetition rates is revealed in the continuous frequency tuning range. The trend and optimization of the stable fundamental mode-locking are presented and interpreted. An RF linewidth of a record value of ~30 Hz is demonstrated, which indicates the low noise operation and high stability of the quantum-dot external-cavity passively mode-locked laser

Chaotic emission and tunable self-sustained pulsations in a two-section Fabry-Perot quantum dot laser

We present an experimental study on the intrinsic instabilities of a two electrode InAs/InGaAs Fabry-Perot quantum dot laser in the absence of optical feedback. By individually controlling the current injected in each electrode, different regimes of operation are allowed including tunable self-sustained pulsations and coherence collapse resulting to possible chaotic emission. The origin of these effects does not resign in the presence of optical feedback but is associated to the carrier dynamics of the quantum dot device. A numerical analysis on the time traces collected from the device reveals high complexity output in terms of correlation dimension. (c) 2011 American Institute of Physics. [doi: 10.1063/1.3552962