Optical sensing refers to the use of optical technologies for detecting and measuring various physical properties or chemical substances. This includes devices such as sensors, detectors, and other instruments that utilize light or electromagnetic radiation to capture and analyze data. Optical sensing has a wide range of applications in fields such as environmental monitoring, medical diagnostics, industrial quality control, and security. It offers advantages such as high sensitivity, non-invasiveness, and the ability to measure multiple parameters simultaneously. Optical sensing techniques include spectroscopy, interferometry, imaging, and fiber optics, among others. Research in optical sensing focuses on developing new technologies, improving sensitivity and selectivity, and exploring novel applications in various industries.