The science of radiation measurement. Raman Amplifier: An optical amplifier based on Raman scattering which generates many different wavelengths of light from a nominally single-wavelength source by means of lasing action or by the beating together of two frequencies. The optical signal can be amplified by collecting the Raman scattered light.
The technique of measuring radiant energy, especially radiant energy in that portion of the total electromagnetic spectrum lying adjacent to the visible region. Radiometry is to be distinguished from the closely related subject of photometry, the latter being specifically concerned with the quantitative response to visible radiation of the human eye. See actinometer.
In optics, radiometry is the field that studies the measurement of electromagnetic radiation, including visible light. Note that light is also measured using the techniques of photometry, which deal with brightness as perceived by the human eye, rather than absolute power.
Methods of calculating an age for geologic materials by measuring the amounts of short-half-life radioactive elements, such as carbon-14, or of long-half-life radioactive elements plus their decay products, such as potassium-40/argon-40.