Measurement and characterization of laser chirp of multiquantum-well distributed-feedback lasers

Abstract

Abstract-Measurements of relative intensity noise and modulation response, before and after propagation in optical fiber, of the output field of multiquantum-well distributed-feedback (MQW-DFB) lasers are used to determine the influence of the intraband damping mechanisms, the DFB structure and the carrier transport and carrier capture into the QW's on the laser chirp. The power dependence of the linewidth enhancement factor is shown to explain the saturation of the laser linewidth at high optical powers.

Intensity modulation and chirp of 1.55-/spl mu/m multiple-quantum-well laser diodes: modeling and experimental verification

“…Recently, the dynamical properties of quantum-well (QW) lasers have been studied by including an additional rate equation for the unconfined carriers in the core region [16]- [19]. While the modulation response of such lasers is well understood, the chirp is still a subject of debate [20], [21]. However, in most cases, model validity was only verified by comparing measured and simulated intensity modulation (IM) waveforms.…”

Large-signal theory of the effect of dispersive propagation on the intensity modulation response of semiconductor lasers

“…The method presented in [5] allows precise determination of the PIR. Here, we used instead a simpler method that consists of fitting the small-signal transfer function to the theoretical PIR for a MQW laser [6]. This method is accurate enough and overcomes the problems encountered with other oversimplified techniques (see [5] for more details).…”

“…The ratio , where , will be referred to in what follows as the phase-to-intensity (modulation index) ratio, PIR. For light produced by a semiconductor laser, the PIR is a function of the modulation frequency, and can be expressed as PIR (2) where is the linewidth enhancement factor, and is related to several laser parameters and contributes to a quasi-adiabatic chirp [5], [6]. Equation (1) indicates that the electric field spectrum consists of sidebands at harmonics of the modulation frequency centered on the laser optical frequency.…”

Analysis and modeling of ridge waveguide quarterly wavelength shifted distributed feedback laser with three rate equations

“…Although there have been many researches and investigations on DFB lasers, their optimization and characteristics investigation are on-going research subjects of recent years [40][41][42][43][44][45][46][47][48][49][50].…”