Abstract: In the processing of high-frequency broadband signals, microwave electronics has long been constrained by the bandwidth, transmission loss, and electromagnetic interference of electronic devices. Modulating signals onto optical carriers for generation, transmission, and processing can effectively circumvent these limitations, which constitutes the core paradigm of microwave photonics. In recent years, driven by the increasing demand for integration, this concept of “optoelectronic fusion” has been extending from the system-link level down to the chip, device, and material levels. Taking the research work of related teams from the School of Optoelectronic Science and Engineering at the University of Electronic Science and Technology of China (UESTC) as examples, this paper reviews the key technologies across three levels along this trajectory: At the system level, it introduces how optoelectronic oscillators (OEOs), optical frequency combs (OFCs), and photonic analog-to-digital converters (photonic ADCs) achieve low-phase-noise signal generation and broadband signal sampling. At the supporting level, it discusses the characterization and testing challenges faced by high-speed optoelectronic chips, including wafer-level non-invasive probing and frequency response decoupling, which are essential prerequisites for transitioning devices toward engineering applications. At the material level, it highlights the applications of two-dimensional (2D) sliding ferroelectric materials in in-memory computing devices, as well as multi-dimensional optical field photodetectors for capturing multi-parameter information such as polarization. Collectively, these three levels reflect the technological evolution of optoelectronic fusion from links to devices and from discrete components to integrated systems, while indicating that intrinsic fusion at the material and device levels will be a critical direction for future breakthroughs.