Professor Juejun Hu’s research group focuses on novel materials and devices to exploit interactions of light with matter. Their work covers a wide spectrum of applications, including on-chip sensing and spectroscopy. Capitalizing on a digital Fourier transform technology, Professor Hu and his research group colleagues have created miniaturized and rugged sensors that can be mass produced for industrial process control, medical imaging, and space applications. Another application is optical phase change materials and meta-optics. Optical phase change materials is a class of materials whose optical properties are modified upon undergoing a solid-state phase transition. Using these materials, the group has pioneered a series of cutting-edge reconfigurable optical devices that can be re-programmed to adapt to specific tasks. Other applications are flexible photonics and polymer photonics for biomedical monitoring and high-speed data communications, optics for imaging and sensing for consumer and automotive electronics, and magneto-optical isolation. This work involves chip-scale one-way valves for photons that will become an integral part of next-generation optical communication and navigation systems.