Modulation Properties of Self-Injected Quantum-Dot Semiconductor Diode Lasers

Abstract

International audienceThis paper investigates the modulation properties of self-injected quantum-dot semiconductor lasers. Using a semianalytical approach, the modulation characteristic of a quantumdot nanostructure laser operating under the influence of optical feedback is successfully modeled. This novel approach derives a feedback induced modulation response model based on the incorporation of the specific quantum nanostructure carrier dynamics as well as the effects of nonlinear gain. This work investigates the impacts of the carrier capture and relaxation time as well as other material parameters such as linewidth enhancement factor, differential gain and gain compression factor for different feedback configurations. It is also shown that, under the short external cavity configuration, the dynamic properties such as the relaxation frequency as well as the laser's bandwidth can be improved through controlled optical feedback. On the other hand, numerical results show that under the long external cavity configuration, any small back-reflection from the laser's facets combined with the large variations of linewidth enhancement factor would significantly alter the laser's modulation response

Impact of gain compression factor on modulation characteristics of InGaAs/GaAs self-assembled quantum dot lasers

“…Quantum dot lasers suffer from larger gain compression factors (10 À22 -10 À21 m 3 ) as compared to their quantum well counterparts (10 À25 -10 À23 m 3 ) which can also alter the modulation dynamics [32]. Figure 5 illustrates modulation response for different gain compression factors.…”

Multimode optical feedback dynamics of InAs/GaAs quantum-dot lasers emitting on different lasing states

“…10,11 However, this enhanced robustness to optical perturbations which is mainly due to the large damping of the relaxation oscillations also sets the limit of the laser's modulation capabilities to few GHz at room temperature. 11,12 In order to increase both speed and reach, prior arts have proposed to take advantage of stimulated emission originating from the excited states (ESs) transitions. 13 Owing to the faster carrier capture from the surrounding carrier reservoir as well as a higher saturated gain, 14 ES QD transmitters have been touted to be a promising solution for high-speed applications.…”

Frequency-dependent linewidth enhancement factor of optical injection-locked quantum dot/dash lasers

“…On the other hand, tremendous efforts have been made to improve the dynamical performance of directly modulated semiconductor lasers by using high-quality materials and optimization of device structure. Moreover, further improvements can be achieved through employment of nonlinear photonic techniques like optical injection, optical feedback, and gain lever configuration [5,6]. In particular, the former relies on the injection of a single-mode master laser's light into a slave laser.…”