Multimode dynamics of semiconductor lasers (original) (raw)

Multimode dynamics of semiconductor lasers

2004

In this manuscript we analyze the modal dynamics of multimode semiconductor quantum-well lasers. Modal switching is the dominant feature of the devices analyzed and it obeys a highly organized antiphase dynamics which leads to an almost constant total intensity output. For each active mode a regular switching at frequencies of few MHz is observed. The activation order of the modes follows a well defined sequence starting from the lowest wavelength (bluest) mode to the highest wavelength (reddest) mode, then the sequence starts again from the bluest mode. Using a multimode theoretical model and a simpler phenomenological model we identify that four wave mixing is the dominant mechanism at the origin of the observed dynamics. The asymmetry of the susceptibility function of semiconductor materials allows to explain the optical frequency sequence.

Dynamics of multimode semiconductor lasers

Physical Review A, 2004

We analyze multi-longitudinal-mode semiconductor lasers experimentally. We show that the intensity of each mode displays large amplitude oscillations but obeys a highly organized antiphase dynamics leading to an almost constant total intensity output. For each mode, regular switching is observed in the megahertz range, while the optical frequency as a function of time follows a well defined sequence from blue to red. Using a multimode theoretical model, we identify that four-wave mixing is the dominant mechanism at the origin of the observed dynamics. The asymmetry of the susceptibility function of semiconductor materials allows us to explain the optical frequency sequence.

Mode-switching in semiconductor lasers

IEEE Journal of Quantum Electronics, 2004

In this paper, we experimentally analyze the modal dynamics of quantum-well semiconductor lasers. Modal switching is the dominant feature for semiconductor lasers that exhibit two or several active longitudinal modes in their time-averaged optical spectrum. In quantum-well lasers, these dynamics involve a periodic switching among several longitudinal modes, which follows a well-determined sequence from the bluest to the reddest mode in the optical spectrum. This feature is radically different from the well-known noise-driven mode-hopping occurring in bulk lasers which involves only two main modes. We analyze the differences in modal dynamics for these two kinds of laser by comparing the modal switching statistics and by studying the effects of noise and modulation in the pumping current.

Multimode Analysis of High-Speed Multiple-Quantum Well Semiconductor Laser

2020 15th International Conference on Computer Engineering and Systems (ICCES)

This paper introduces analysis of mode dynamics in multiple-quantum well (MQW) laser as a promising device for high-speed photonics. The study is based on a multimode model of semiconductor laser under direct intensity modulation. The simulation results are used to investigate the influence of the injection current on the dynamics of the non-modulated multimode laser, as well as influence of the modulation parameters (modulation index and modulation frequency) on the dynamics of the laser. The modal oscillations and the associated multimode hopping that characterizes the long-wavelength laser are investigated in both the non-modulated and modulated laser. The coupling among the oscillating modes under both cases is evaluated in terms of their correlation coefficients. Dependence of the small-signal modulation response and bandwidth on the bias current is introduced. In addition, we present comparison of the modulation response of the total output with those of the strongest oscillating modes.

Direct Modulation Performance of Quantum Well Semiconductor Laser Diodes Operating in Multimode

Dhaka University Journal of Applied Science and Engineering

A theoretical investigation has been carried out for both the direct sinusoidal modulation and associated noise performance of InGaN based quantum well (QW) semiconductor laser diodes (LDs) operating in multimode. The study is based on the QW lasers with two separate quantum wells with different carrier injection ratios. A model of multimode rate equations is developed by taking into account both symmetric and asymmetric cross-gain saturation. Numerical simulation shows that the mode partition effect exists in both the modulated and unmodulated LDs. From modulation at microwave frequency, highly synchronized oscillation of the modes resulting periodic pulse-like output is observed that contains peaks at modulation frequency and its harmonics. Associated total RIN and modal RIN values suppress with the modulation index. The simulation results have well correspondence with the previously reported theoretical and experimental findings. DUJASE Vol. 6 (2) 94-98, 2021 (July)

Nonlinear dynamics in directly modulated multiple-quantum-well laser diodes

IEEE Journal of Quantum Electronics, 1997

A theoretical and experimental analysis of the nonlinear dynamics of Fabry-Perot (FP) and distributed feedback (DFB) multiple-quantum-well (MQW) laser diodes is presented. The analysis is performed under single-tone and two-tone direct modulation. In the FP laser, we observe period doubling and in the DFB laser both period doubling and period tripling are identified. Period doubling is found over a wide range of modulation frequencies in both lasers. The reason for this wide modulation frequency range is attributed to the large relaxation frequencies found in MQW laser diodes. The spontaneous emission factor is measured for both FP and DFB lasers. The dependencies of period doubling on output power and RF input power level are also analyzed. The nonlinear dynamics of the laser are found to be enhanced when modulated under two-tone modulation. Numerical simulations carried out show good agreement with the measured results.

Multimode semiconductor laser: quantum versus classical behavior

2018

Temporal correlations of radiation intensities of a multimode Fabry-Perot semiconductor laser are investigated. Strong intensity correlations with a fixed phase shift between different longitudinal modes of the laser are revealed. The second g^(2) and third g^(3) order intensity correlation functions are studied to clear the character of the intermodal coupling.

Quantum fluctuations in multimode semiconductor lasers

Journal of Optics B: Quantum and Semiclassical Optics, 2002

We derive a quantum macroscopic model for a multimode semiconductor laser, starting from a complete microscopic description. Nonlinear gain terms describing saturation and mode-mode interaction are obtained by a suitable treatment of the spectral hole burning in the distribution of carriers. In the case in which there are two neighbouring active longitudinal modes above threshold and for quiet pumping, we calculate the spectrum of the total intensity fluctuations at zero frequency. For moderate pumping level the nonlinear gain terms do not reduce the degree of anticorrelation between modes, leaving the squeezing in total intensity unchanged with respect to the single-mode case. Only for very high pumping does the nonlinear gain suppression become relevant, and the total intensity noise is increased.