Optics is the area of physics that involves the study of electromagnetic waves in the visible-light spectrum, between 380 and 700 nm. Optics principles also apply to lasers, which are used in industry and medicine. Each laser has a specific wavelength. There are lasers that use wavelengths in the 100–400 nm range, others that use a wavelength in the visible spectrum, and some that use wavelengths in the infrared spectrum (greater than 700 nm).

Salem Press Encyclopedia of Science, 2022. 3p.