Energy State: A way to describe the value of the energy associated with a particular object. Photoelectric Effect: The relationship between the wavelength of light and the appearance of photoelectrons...Energy State: A way to describe the value of the energy associated with a particular object. Photoelectric Effect: The relationship between the wavelength of light and the appearance of photoelectrons. Photon: The smallest unit of an electromagnetic wave in the particle model of light. Laser Pumping: The process of transferring energy from the power supply to the gain medium. Quantum Mechanics: The branch of physics that studies the behavior of particles on the atomic and subatomic level.