Wavelength tuning refers to the ability to adjust the wavelength of light emitted or detected by a device. This capability is often important in various applications such as telecommunications, spectroscopy, and sensing. Researchers in this area focus on developing techniques and technologies that can efficiently and accurately tune the wavelength of light sources or detectors to meet specific requirements. This may involve designing new materials, coatings, or components that can shift or control the wavelength of light in a controllable manner. Ultimately, the goal of wavelength tuning research is to enhance the performance and versatility of optical systems and devices for a wide range of applications.