The convergence of optics and electronics, driven by intelligent systems and wearable technologies, demands materials that seamlessly integrate optical transparency with robust electrical and mechanical functionalities. Transparent ferroelectric ceramics (TFCs) have emerged as a pivotal platform in this endeavor, uniquely bridging high optical transmittance with strong ferroelectric, piezoelectric, and electro-optic responses. This review comprehensively charts the evolution of TFCs, from fundamental material design to cutting-edge device applications. We systematically analyze the core strategies for achieving transparency in two representative transparent ferroelectric ceramic systems, namely lead-based (Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃, abbreviated as PMN–PT) and lead-free ((K,Na)NbO₃, abbreviated as KNN) systems), while also discussing other important systems such as (Pb,La)(Zr,Ti)O₃ (PLZT), BaTiO₃ (BTO), and (Bi_0.5Na_0.5)TiO₃ (BNT) where appropriate for comparison. Critical mechanisms such as grain and domain engineering, refractive-index matching, phase-structure tuning, and defect control. Representative functionalities—including transparent piezoelectricity, electro-optic modulation, energy storage, photoluminescence, and photochromism—are highlighted, with their potential applications evaluated across photoacoustic imaging, adaptive optics, transparent robotics, smart windows, and optical communication. Finally, we identify key challenges and future opportunities, such as high Curie temperature (T_c) design, texture engineering, and multifunctional co-integration. Overall, this review aims to provide theoretical insights and material-design foundations for next-generation multifunctional transparent ferroelectric devices, accelerating their adoption in intelligent sensing, integrated photonics, and transparent optoelectronic systems.

Dual-mode imaging combining photoacoustic and ultrasound modalities holds great promise for comprehensive tissue characterization. In traditional dual-mode imaging systems, however, the opaque ultrasound transducers are integrated in complex optical and ultrasound paths, leading to compromises in imaging efficiency and sensitivity. To address these challenges, we design and produce highly transparent Pb(Mg,Nb)O₃–PbTiO₃ ceramics with exceptional transparency of 68%, alongside a remarkable ultrahigh piezoelectric d₃₃ of 1500 pC/N. Leveraging this material, we fabricate a high-sensitivity transparent piezoelectric ultrasound transducer (TPUT) with a center frequency of 16 MHz and a bandwidth of 30%, which seamlessly integrating ultrasound and photoacoustic capabilities into one system to achieve simultaneous photoacoustic/ultrasound dual-mode imaging, showcasing a remarkable sensitivity for deep-tissue detection (e.g., 7.5 mm thick chicken breast meat). Additionally, in vivo photoacoustic imaging of subcutaneous microvasculature in a mouse ear was successfully achieved via 28 MHz TPUT. Our innovation not only advances imaging performance but also offers a cost-effective solution, paving the way for transformative biomedical imaging applications.