Electromagnetic radiation refers to the waves of electric and magnetic fields that propagate through space.

The Wikipedia page for "Electron" provides a comprehensive summary of the subatomic particle known as an electron.

A femtosecond is a unit of time in the International System of Units (SI) equal to 10−15 or 1/1 000 000 000 000 000 of a second; that is, one quadrillionth, or one millionth of one billionth, of a second.

Infrared is a type of electromagnetic radiation, which lies beyond the visible spectrum of light.

The International System of Units (SI) is a globally accepted and standardized system of measurement used in various fields such as science, engineering, and trade.

A photon is a fundamental particle in the field of physics, specifically in the area of quantum mechanics and electromagnetism.