Low threshold current and high differential gain in ideal tensile- and compressive-strained quantum-well lasers

Abstract

We use an idealized band structure to compare the characteristics of tensile- and compressive-strained quantum-well lasers. We show that although the threshold carrier density increases as expected in tensile-strained lasers, both the radiative current density and differential gain can be comparable to or improved over compressively strained lasers.

Low-threshold GaInAsSb/AlGaAsSb quantum well laser diodes emitting near 2.3 µm

“…We attribute this low value to the low values of both internal losses and transparency current density, the latter being related to the mass ratio m v /m c (m v and m c are the effective masses of holes and electrons in the QW). It has been shown that the transparency current density decreases with m v /m c [6]. For compressively strained QWs made of GaInAsSb with the above-mentioned composition, m v and m c equal 0.034 m 0 and 0.033 m 0 respectively, leading to a mass ratio m v /m c being near unity.…”

Theory of the Electronic and Optical Properties of Dilute Bismide Quantum Well Lasers

“…The reduction in the calculated radiative current density at transparency, J tr rad , arises directly from the reduced magnitude of the interband optical matrix elements. In the Boltzmann approximation, J tr rad should vary as eBn 2 tr , with the radiative recombination coefficient B being directly proportional to the average value of the interband optical matrix elements [59], [60], [61]. Because of the reduction in the magnitude of the interband optical matrix elements, we calculate a lower value of J tr rad over the full temperature range investigated in the Bi-containing QW, as well as larger peak gain at low and intermediate values of J rad compared to the Bi-free QW.…”

Temperature analysis and characteristics of highly strained InGaAs-GaAsP-GaAs (λ < 1.17 μm) quantum-well lasers

“…By contrast, there have also been several predictions [3], [51] that the expression for the coefficient should be proportional to the inverse of the temperature, . For our purposes, the model of the coefficients can be expressed as , in which varies from 0 to 1.…”

“…For the case of a laser with approximately to zero, the predicted values are approximately less than three times smaller than the values for the nonradiative recombination dominated lasers. The activation energy has been shown to range from 20 to 60 meV depending on the type of the active regions and the barriers surrounding the active regions [3], [51]. By assuming a room-temperature measurement ( 300 K), and the activation energy, , to range from 20 to 60 meV, the predicted values for the Auger recombination dominated lasers should range from 55 to 79 K, which is also in agreement with the measured (64 K) of InP-based 1.3-m lasers [52].…”