Direct observation of longitudinal spatial hole burning in semiconductor optical amplifiers with injection

Abstract

Measurements of spontaneous emission from InGaAsP semiconductor optical amplifiers provide information on both the carrier density and temperature. By spatially resolving the light emitted along the active layer of the device, we find evidence of longitudinal spatial hole burning which results from amplified spontaneous emission in the structure and is modified by the injected optical signal. Under injection, we also observe pronounced asymmetry of the amplified spontaneous emission intensity from the two facets which we relate to the carrier density profile. The experimental results are in good agreement with numerical simulations. An analysis of the measured spectra reveals an unexpected very high temperature (400 K) and its decrease by at least 35 K in the middle of the device when light is injected.

Saturation and noise properties of quantum-dot optical amplifiers

“…In the presence of an optical signal the ASE and carrier distributions are redistributed similarly to the case of bulk and QW SOAs [34], [48]. Thus the consumption of carriers through stimulated emission with the signal reduces the population inversion toward the rear of the device, which results in a smaller amount of backward traveling ASE, especially at the barrier and WL transitions.…”

“…A high value for the temperature of 380 K corresponding to a worst-case scenario is used in order to partially compensate for the fact that heating is not included in the model. Carrier heating has been pointed out be present both in bulk [48] SOAs and QD lasers [24], [53], and is also expected to be an issue in the context of QD SOAs.…”

Wideband Steady-State Model of a Strained InGaAsP MQW-SOA

“…Prediction of the latter is of particular importance in SOAs [17]. The model does not include the effects of Auger related carrier heating, which can impact on the shape of the ASE spectra particularly at high carrier densities [18].…”

Longitudinal spatial hole burning in terahertz quantum cascade lasers

“…In semiconductor lasers and amplifiers it contributes negatively to linewidth broadening, mode hopping, gain compression, and gain nonlinearity. [1][2][3][4][5][6][7] LSHB is a result of the delicate local balance between the photon and charge carrier densities in the active region of a semiconductor laser. Nonuniform optical mode intensity creates a nonhomogeneous carrier distribution due to fast electron-hole recombination associated with the stimulated emission.…”