Effect of the number of stacking layers on the characteristics of quantum-dash lasers

Abstract

A theoretical model is evaluated to investigate the characteristics of InAs/InP quantum dash (Qdash) lasers as a function of the stack number. The model is based on multimode carrier-photon rate equations and accounts for both inhomogeneous and homogeneous broadenings of the optical gain. The numerical results show a non monotonic increase in the threshold current density and a red shift in the lasing wavelength on increasing the stack number, which agrees well with reported experimental results. This observation may partly be attributed to an increase of inhomogeneity in the active region. ©2011 Optical Society of America

Investigation of Chirped InAs/InGaAlAs/InP Quantum Dash Lasers as Broadband Emitters

“…Moreover, a smooth L-I curve in this case is a consequence of reduced photon re-absorption process in the system. This is a direct effect of comparatively less inhomogeneous system compared to W = 2 μm case [29]. On the other hand, the lasing spectrum of W = 4 μm laser show no signs of spectral split and instead a typical broadening of single emission lobe is observed.…”

Chirped InAs/InP quantum-dash laser with enhanced broad spectrum of stimulated emission

“…We demonstrated a high power $(0.6) 1.0 W broad stimulated emission $(22) 41 nm full width at half maximum (FWHM) from as grown (intermixed) InAs/InP Qdash lasers emitting in the L (C) bands. [6][7][8][9] In the short wavelength InAs/GaAs Qdot structures, a FWHM of $22 (75) nm with high power $0.5 (0.75) W, has been reported, employing standard (chirped) double-heterostructure design. [10][11][12] This enhancement in the lasing bandwidth offered by chirping forms a potentially viable platform, and the realization of such devices would offer compact, high-efficiency, and cost-effective solution in optical communications, medical imaging, metrology, and spectroscopy and sensing.…”

Spectral Analysis of Quantum-Dash Lasers: Effect of Inhomogeneous Broadening of the Active-Gain Region

“…Our simulation results do show a red shift in the central lasing wavelength as a function of stack number and at fixed active region inhomogeneity. This observation might be attributed to the decrease in the optical confinement factor as the number of stacking layers increases which is comprehensively studied by our group recently [19]. In addition, Fig.…”

“…Various theoretical techniques for modeling the performance characteristics of Qdashes at material level [2,[12][13][14][15], and device level [3,[16][17][18][19][20], have been reported in literature. However, not many of these models analyzed the spectral characteristics of InAs/InP Qdash lasers except for [16,17], and very recently by our group [18,19], where we made an effort to explain the red shift of lasing wavelength with increasing cavity length or the number of stacking layers by relating these to inhomogeneous broadening (Qdash size of composition dispersion), and considering a qualitative model. The objective of this paper is to gain a further comprehensive understanding of the red shift phenomenon in Qdash lasers, which has been observed experimentally [6,9].…”