Integrated photonics enables the synthesis, processing and detection of optical signals using photonic integrated circuits (PICs). It has rapidly transformed numerous fields and applications by enabling faster and more efficient ways to process and transmit information, as well as new techniques for telecommunications, sensing, medical diagnosis, and quantum computing, just to name a few. With its intrinsic high speed, large bandwidth, and unlimited parallelism, integrated photonics plays a critical role in handling high-throughput, data-intensive applications. Over the past few decades, the successful translation from laboratory research to commercial deployment has established integrated photonics as a standard technology widely used in high-data-rate telecommunications and datacenters. With the development of heterogeneous integration for various material platforms, researchers have demonstrated myriad novel devices, including miniaturized classical and quantum light sources, micro-resonator frequency combs, ultrafast electro-optic modulators, programmable MEMS-controlled circuits, and large-scale on-chip photonic networks. These advancements are continuously impacting our society and opening up new opportunities in areas such as optical communications, photonic computing, frequency metrology, and LiDAR.

Optical microresonators have been one of the most active and exciting research topics in the photonics community in recent years. By confining light in both spatial and time domain, optical microresonators serve as an indispensable platform for significantly enhancing light–matter interaction and controlling light fields at the micro- and nano-scale. These capabilities make optical microresonators important tools for a wide range of applications, including sensing, metrology, communication, and quantum computing.

The high-energy pulsed laser with green light band (500-560nm) has great application value in scientific research fields such as earth-moon ranging, underwater detection, biomedicine, industrial processing and so on. At the same time, using green pulsed laser as the fundamental frequency light is the most effective and widespread method to generate ultraviolet and deep ultraviolet laser. At present, the mainstream technology to generate high-energy pulsed green laser is still nonlinear frequency conversion (such as frequency doubling/summing) of near-infrared solid or fiber lasers. Due to its large size and complex maintenance, it is difficult to meet the requirements of many applications requiring miniaturized laser, such as airborne, shipborne, earth-moon and underwater detection. Researchers have been seeking a solution for pulsed green laser with high efficiency, small size and free maintenance.

In optical imaging, "phase" is one of the most important components of the light field (strictly speaking, monochromatic coherent light field). Especially in the field of optical microscopic imaging, most objects are phase objects with weak absorption, where the amplitude of light passing through the object (e.g., a cell) is almost constant, while the phase of transmitted light contains crucial information about the sample, such as 3D morphology and refractive index distribution. The acquisition of phase information is particularly significant, has driven the emergence of "phase measurement" technology. At present, "phase measurement" as a major research direction in the field of optical microscopic imaging, and has been widely applied in the fields of pathology, biological cytology and drug development.