Cover illustration
This review synthesizes recent research on the longitudinal polarization engineering, emphasizing its theoretical foundations, generation methodologies, and transformative implications. For more details, please refer to the article “Longitudinal modulation on light field polarization” by Xinhao Fan, Bingyan Wei, Yi Zhang, Sheng Liu, Peng Li, and Jianlin Zhao, published in Front. Phys. 21(2), 022201 (2026). [Photo Credits: Peng Li at Northwestern Polytechnical University]