Optical metrology is the science and technology of measurement with light. It involves the use of optical instruments to enable an uncountable number of applications.
Instruments and sensors prototyping is the process of developing and building experimental devices and sensor systems to test and validate their design, functionality and performance.
Biological systems can be studied by combining biology, physics, and engineering to learn about their interaction with light. This interdisciplinary field is called Biophotonics.
Radiometry is the science of measuring electromagnetic radiation. Photometry instead, uses light as perceived by the human eye and its sensitivity to different wavelengths.