Simulation and Fabrication Feasibility of Two-Channel All-Optical Modulator Exploiting InAs/AlAs Colloidal Quantum Dots

In the context of advancing photonics technologies, there is an increasing demand for broadband and ultrafast optical modulators to support next-generation telecommunication networks and ultrafast quantum information processing. Existing modulators are limited by their inability to efficiently handle multiple channels, leading to challenges in high-speed optical communication systems. We introduce a novel two-channel quantum dot all-optical modulator (QD-AOM) designed to simultaneously modulate telecommunication wavelengths of $1.32~\mu $ m and $1.55~\mu $ m by utilizing the interaction between two pump signals (683 nm and 866 nm) and two probe signals ( $1.32~\mu $ m and $1.55~\mu $ m). This innovative device leverages InAs/AlAs core/shell colloidal quantum dots, offering a scalable, cost-effective, and efficient solution for next-generation optical communication networks and ultrafast quantum information processing. Theoretical modeling was performed by solving the 3D Schrödinger equation, coupled rate and propagation equations to simulate the device’s performance. The model accounts for carrier transfer processes and the interaction between channels through Fluorescence Resonance Energy Transfer (FRET). Simulations demonstrated that the QD-AOM achieved modulation depths of 65% and 62% for channels corresponding to $1.55~\mu $ m and $1.32~\mu $ m, respectively, with bandwidths of 26.3 GHz and 19.7 GHz. The device maintained high stability and efficiency at room temperature, with minimal variation in modulation depth across different temperatures, indicating its robustness for practical applications. Its broadband response, high modulation depth, and robust performance make it an ideal candidate for integration into future high-speed communication systems, signal processing, and other photonics-based applications.