In this paper, to reduce system complexity and improve performance, we propose a novel compact photonic quantization scheme based on dual-output Mach–Zehnder modulators (DOMZMs). By exploiting the complementary outputs of DOMZMs and introducing a cross-channel differential combination strategy, multiple effective quantization channels are generated without increasing the number of modulators. Furthermore, an adaptive thresholding mechanism based on intrinsic signal intersections enables direct Gray code output with improved noise tolerance. Proof-of-concept experimental results fully confirm the correctness of the principle, and 4-bit quantization is successfully demonstrated. Experimental and numerical results both demonstrate good linearity over the full-scale input range, and confirm the feasibility of the proposed scheme. More performance evaluations are provided through simulations. We also discuss challenges relating to practical deployment of the proposed approach. The presented approach provides a promising solution for compact photonic analog-to-digital conversion systems.
Wei et al. (Thu,) studied this question.