Here, we present a method, based on Stark shifts induced by the quantum-confined Stark effect, to directly determine the piezoelectric field in strained zinc-blende quantum wells (QWs) grown along the 111 direction and embedded in the p–i–n diode structure (p-iMQW-n) of a semiconductor optical amplifier. Under short-circuit and open-circuit conditions and resonant optical excitation, we experimentally determine the energy of the 1s e-hh excitonic resonance and the potential difference across the p-iMQW-n junction. Using these parameters in an analytical expression derived in this work, we directly determined a piezoelectric field of −108.71 ± 8.51 kV/cm acting on each of the eight 12-Å-wide strained [111]-oriented In_0.687Ga_0.313As /In_0.807Ga_0.193As_0.304P_0.696 QWs of a semiconductor optical amplifier (SOA). The theoretical prediction of −112.24 kV/cm was in very good agreement, within the experimental error, with the value of the piezoelectric field extracted through the proposed procedure, which was also indirectly validated by comparing the experimental value of the 1s e-hh excitonic resonance Stark shift with the extracted one. Even though the implemented technique was specially designed to experimentally determine the piezoelectric field acting on each of the QWs of a multiple quantum well SOA, it can be applied to any p–i–n structure with electrodes and strained [111]-oriented zinc-blende QWs embedded in its intrinsic region. Remarkably, the method proposed here allows direct experimental determination of the piezoelectric field through an analytical expression, with which it is also possible to estimate, with high reliability, the precision of the result and how it is affected by the accuracy of each measuring instrument intervening in the procedure.

We have inserted into an unbiased semiconductor optical amplifier (SOA) a powerful control beam, with photon energy slightly smaller than that of the band-gap of its active region, for exciting two-photon absorption and the quadratic Stark effect. For the available SOA, we estimated these phenomena generated a nonlinear absorption coefficient $\beta =$−865 cm/GW and induced an appreciable birefringence inside the amplifier waveguide, which significantly modified the polarization-state of a probe beam. Based on these effects, we have experimentally demonstrated the operation of an all-optical buffer, using an 80 Gb/s optical pulse comb, as well as an unbiased SOA, which was therefore, devoid of amplified spontaneous emission and pattern effects.

Here, we present a study of the effective piezoelectric constant (e14_e) temperature dependence in strained [111]-oriented zinc-blende quantum wells (QWs) embedded within a semiconductor optical amplifier (SOA). We determined e14_e using a method that was insensitive to the segregation phenomenon and to the temperature dependence of the bandgap energy, which required neither fitting parameters nor temperature-dependent expressions for energy and out-of-plane effective masses of electrons and heavy holes. An e14_e=-0.0534±0.0040 C · m^-2 at 23°C was obtained for an SOA with 1.2 nm [111]-oriented strained In_0.687Ga_0.313As/In_0.807Ga_0.193As_0.304P_0.696 QWs. Unlike previously published research, where e14_e magnitude increased as temperature rised, we extracted an e14_e magnitude that decreased as temperature increased.