A review of tunable photonics: Optically active materials and applications from visible to terahertz

The next frontier of photonics is evolving into reconfigurable platforms with tunable functions to realize the ubiquitous application. The dynamic control of optical properties of photonics is highly desirable for a plethora of applications, including optical communication, dynamic display, self-adaptive photonics, and multi-spectral camouflage. Recently, to meet the dynamic response over broad optical bands, optically active materials have been integrated with the diverse photonic platforms, typically in the dimension of micro/nanometer scales. Here, we review recent advances in tunable photonics with controring optical properties from visible to terahertz (THz) spectral range. We propose guidelines for designing tunable photonics in conjunction with optically active materials, inherent in wavelength characteristics. In particular, we devote our review to their potential uses for five different applications: structural coloration, metasurface for flat optics, photonic memory, thermal radiation, and terahertz plasmonics. Finally, we conclude with an outlook on the challenges and prospects of tunable photonics.

Automated summary

The development of photonics has entered a new stage, where reconfigurable platforms with tunable functions are used to achieve versatile applications. Recent research has focused on integrating optically active materials into photonic platforms to dynamically control optical properties. This review explores the potential uses of tunable photonics in five application areas: structural coloration, metasurface for flat optics, photonic memory, thermal radiation, and terahertz plasmonics, and provides guidelines for designing tunable photonics based on wavelength characteristics.