Fluence

Energy densityMass of an object divided by its volume. Density is a characteristic property of a substance (rock vs. ice, e.g.). Some substances (like gases) are easily compressible and have different densities depending on how much pressure is exerted upon them. The Sun is composed of compressible gases and is much Click on Term to Read More from an optical source impinging on a sample. The higher the energy density, the higher the fluence. Fluence is measured in Joules per square centimeter, (J/cm)