مشخصات پژوهش

The rapid evolution of high-speed optical communication networks has intensified the demand for ultra-high-capacity links, positioning electro-optic modulators (EOMs) and Mach–Zehnder interferometers (MZIs) as pivotal components in microwave photonic systems. However, the performance of these devices is fundamentally limited by nonlinear effects, which induce harmonic distortions and intermodulation products. In this paper, we propose a generalized analytical framework to characterize the output frequency spectrum and temporal waveform of an EOM-MZI modulator. Our model incorporates a quadratic refractive index profile and utilizes a Fourier series representation of the driving signal in conjunction with a multi-harmonic Jacobi–Anger expansion to provide closed-form solutions for the modulated optical field. The proposed framework is rigorously validated against numerical simulations for bit rates ranging from 5 to 50 Gbps. Results demonstrate high precision, with the model accurately capturing complex nonlinear behaviors and intermodulation products. Furthermore, we investigate the impact of pulse duty cycle optimization, revealing that for ultra-high-speed operations (above 35 Gbps), reducing the duty cycle to 30% significantly enhances the extinction ratio and Q-factor by mitigating nonlinear distortions. This analytical approach offers a computationally efficient alternative to intensive numerical solvers, providing a robust tool for the design and optimization of next-generation high-speed optical communication links. The proposed framework enables simultaneous analysis of spectral broadening, harmonic generation, intermodulation effects, and waveform distortion in both frequency and time domains.