<p>Quantum optical integrated circuits are revolutionizing quantum information processing by utilizing integrated photonics technology to create complex optical circuits on a single chip. Historically, these circuits encountered various challenges in quantum applications, but recent advancements have enabled them to meet the rigorous demands of both research and industry. A key area of exploration is the establishment and maintenance of quantum properties within photonic substrates. Bragg grating structures, essential for many optical applications, are anticipated to significantly contribute to the development of integrated circuits. However, they face a challenge with dispersion, which can threaten the integrity of quantum states. When entangled photons pass through a waveguide, their correlation function tends to broaden due to this dispersion. To address this issue, the study emphasizes the importance of apodizing the grating structure, as this can help reduce the broadening of the correlation function, provided that the apodization function’s standard deviation can adapt to variations in the refractive index. The proposal of apodized waveguide gratings aims to enhance the correlation of biphotons, offering a promising strategy for advancing the field.</p>