Light field imaging is a 3D imaging technology. In light field imaging, the projection of 3D object to light field information on 2D image plane (including spatial and directional information of incident light) will be conducted by micro-lens array. Then 3D reconstruction of object will be realized through the processing of light field information. Light field imaging has the feature of high-temporal-resolution with scanning-free 3D imaging process and has no requirement of special illumination. Therefore, light field imaging has shown significance in research fields and applications, such as biological imaging, industrial measurement and machine vision.

Advanced microscale silicon photonics technology has emerged as a promising candidate for the next-generation chip-scale data communication network due to its unique advantages of low cost, high integration density, high speed and energy efficient. However, a highly efficient microscale Si-based light source is still considered as the obstacle for realizing a practical Si-based photonic integrated circuit (PIC), due to the indirect bandgap nature of bulk Si and Ge materials.

Chinese Optics Letters (COL) invites high quality articles for a Special Issue on Optical Metasurfaces: Fundamentals and Applications to be published in Jan. 2023. Optical Metasurfaces are ultrathin optical designs composed of subwavelength meta-atoms, and have demonstrated unprecedented capabilities in manipulating light propagation. After tremendous research during the past decade, the working principle of metasurfaces has be extended from initial resonance of meta-atoms to non-resonant geometric phase and dynamic propagation phase. The constituent materials have been extended from metals to dielectrics to further reduce the loss, and make the high-efficiency devices more applicable. By now, numerous functionalities have been realized, such as beam engineering, waveplates, polarizers, holograms, metalenses, and so on. People are expecting a new version of metasurface 2.0 that will not only enrich the frontiers of optical sciences but also revolutionize the traditional optical devices and technology in real applications.

As is well-known, every hot object with a temperature above absolute zero, whether artificial or natural, will emit thermal radiation. In nature, many organisms achieve better survival by adjusting their own infrared (IR) radiation. In particular, rattlesnakes can detect prey at night rely on their IR-sensitive pit organs. To threaten rattlesnakes, ground squirrels send out distinct and deceptive infrared tail flagging signals by increasing blood flow to their tails. The total thermal energy radiated from an object is related to its emissivity and temperature, which is based on the Stefan-Boltzmanns law. Consequently, the thermal radiation intensity can be manipulated by adjusting the emissivity or changing the surface temperature to meet different needs. Inspired by natural creatures, the regulation of thermal radiation has been widely used in different fields, including personal thermal management, smart windows, IR camouflage, IR imaging, and so on.