Dynamic Control of Supercontinuum Generation in Semiconductor Quantum Wells through Modulated Nonlinearity and Dispersion

In this article, we present the dynamics of supercontinuum (SC) generation in an asymmetric semiconductor quantum well (SQW) system employing modulated nonlinearity and dispersion under an electromagnetically induced transparency (EIT) window. Specifically, we utilize a weak probe pulse in the system, which is modulated by a strong control field, exploiting the phenomenon of EIT. Adjusting the control field parameters, we obtain large nonlinearities of the order [Formula: see text] and [Formula: see text] at probe wavelengths and [Formula: see text] and [Formula: see text], respectively. The corresponding dispersion values are [Formula: see text] (for anomalous dispersion) and [Formula: see text] (for normal dispersion), respectively. We investigate the generation of a supercontinuum in the system separately for both the dispersion regimes by using a narrow-band Gaussian pulse. In the regime of anomalous dispersion, the broadening of the SC is mainly governed by the nonlinear processes like the self-phase modulation (SPM), the dispersive wave emission and the soliton self-frequency shift. These nonlinearities manifest into a highly modulated spectral profile with a span of around 4 octaves [Formula: see text]. However, in the domain of normal dispersion, the SC is dominated by SPM, extending asymmetrically to the higher wavelength side owing to the third-order dispersion. This results in the formation of a smooth and practically flat spectrum, but with a reduced bandwidth of around [Formula: see text]. Our study highlights the versatility of EIT-assisted nonlinear optical control in SQW systems and refers to their possible use in the development of broadband light sources for spectroscopy, optical communications and the development of integrated photonic devices.