Examinando por Autor "Weisser, Stephan"

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Carrier Capture and Escape Processes in In Ga As-GaAs Quantum-Well Lasers
(IEEE, 1999) Romero, Beatriz; Esquivias, Ignacio; Weisser, Stephan; Larkings, Eric; Rosen, Joseph
We have extracted the ratio between the carrier capture and escape times, eta, for In0.25Gao0.75As-GaAs lasers containing one, two, or three quantum wells, from high-frequency subthreshold impedance measurements at different temperatures. Our results show that the carrier capture process dominates over the diffusion along the confinement region in the overall transport/capture process. The obtained value for eta is comparable to unity, and this fact has to be taken into account to obtain real material parameters, such as the carrier lifetime and the radiative recombination coefficient.
Carrier capture and escape times in In0.35Ga0.65As-GaAs multiquantum-well lasers determined from high-frequency electrical impedance measurements
(IEEE, 1996-10) Esquivias, Ignacio; Weisser, Stephan; Romero, Beatriz; Ralston, John
We present experimental results on the high-frequency electrical impedance of In0.35Ga0.65As-GaAs multiquantum-well lasers with varied p-doping levels in the active region, The analysis of the data, using a simple three rate equation model, provides information about the dynamical time constants (the carrier lifetime, the effective carrier capture and escape times) under the laser operation conditions, The addition of p-doping increases the carrier escape time at threshold from 0.7 ns, extracted for the undoped devices, up to a value higher than 2 ns for the p-doped lasers, The effective capture time is estimated to be between 2 and 5 ps.
Carrier Dynamics and microwave characteristics of GaAs-Based Quantum-Well Lasers
(IEEE Journal of quantum electronics, 1999-04) Esquivias, Ignacio; Weisser, Stephan; Romero, Beatriz; Ralston, John; Rosenzweig, Joseph
We investigate the effects of carrier capture and re-emission on the electrical impedance, equivalent circuit, and modulation response of quantum-well (QW) laser diodes. The electrical impedance is shown to be a sensitive function of the time constants associated with carrier capture/transport and carrier re-emission. We compare the theoretical results with measured values of the electrical impedance of high-speed InGaAs-GaAs multiple-quantum-well lasers fabricated using different epilayer structures with a common lateral structure. The experimental results agree well with the theoretical model, allowing us to extract the effective carrier escape time and the effective carrier lifetime in the QW's, and to estimate the effective carrier capture/transport time
Impedance characteristics of quantum well lasers
(IEEE, 1994) Weisser, Stephan; Esquivias, Ignacio; Tasker, PJ; Ralston, John; Romero, Beatriz; Rosenzweig, Joseph
We derive theoretical expressions for the impedance of quantum-well lasers below and above threshold based on a simple rate equation model, These electrical laser characteristics are shown to be dominated by purely electrical parameters related to carrier capture/transport and carrier re-emission, The results of on-wafer measurements of the impedance of high-speed In0.35Ga0.65As/GaAs multipie-quantum-well lasers are shown to be in good agreement with this simple model, allowing us to extract the effective carrier escape time and the effective carrier lifetime, and to estimate the effective carrier capture/transport time,