Laser Fundamentals Quiz

A process where an atom absorbs a photon and moves to a higher energy state.

A process where an excited atom is triggered to release a photon and move to a lower energy state by external energy.

The light emitted from a laser, characterized by its single color, coherent waves, and parallel, focused beam.

An ordinary beam of light that contains multiple colors, incoherent waves and is not concentrated.

The process by which an excited atom releases a photon and moves to a lower energy state without external stimulation.

The phenomenon where atoms in a lower energy state absorb photons and move to a higher energy state.

Light Amplification by Stimulated Emission of Radiation. This technology uses stimulated emission to create a highly focused, monochromatic, and coherent beam of light.

The invention of lasers occurred between 1959 and 1962. The theory behind stimulated emission was initially proposed by Einstein in 1917.

The process where an atom absorbs a photon and transitions to a higher energy state.

The time an atom remains in an excited state before spontaneously emitting a photon.

Light emitted from spontaneous emission is incoherent, meaning the photons are not in phase with each other.

Light emitted from stimulated emission is coherent, meaning the photons are in phase with each other.

The process amplifies the intensity of radiation because one input photon triggers the release of two photons.

The energy difference between the two energy levels of an atom involved in an absorption or emission process determines the frequency of the emitted or absorbed photon.

The ability of an atom to remain in an excited state for a long time, allowing for a greater chance of stimulated emission and laser operation. These are crucial for creating a population inversion.

Transitions between energy levels of atoms that involve the absorption or emission of light photons.

Transitions between energy levels that occur without the involvement of light photons, usually due to interactions with the environment. These are prevalent in laser materials.

The condition necessary for laser operation, achieved when more atoms exist in an excited state than in the ground state. This allows for a higher probability of stimulated emission, amplifying light.

The property of light where all waves have a consistent phase relationship.

Coherence measured along the direction of light propagation. Think of how consistent the waves are over time and distance.

Coherence measured across the direction of light propagation. Think of how consistent the waves are side-by-side.

The ability of a laser to emit light of a very narrow range of wavelengths. This means it's essentially a single color.

The principle behind lasers where light is amplified by stimulating the emission of photons from excited atoms.

The Doppler effect, where the motion of atoms emitting light causes a slight shift in the wavelength, causing the light to not be perfectly monochromatic.

The process of increasing the population of atoms at a higher energy level to achieve population inversion.

A system where population inversion has been achieved, allowing the possibility of stimulated emission dominating spontaneous emission.

The energy supplied to a system to create population inversion by exciting atoms to higher energy levels.

The range of wavelengths emitted by conventional light sources, usually spanning hundreds of Angstroms.

The narrow range of wavelengths emitted by a laser, typically a few Angstroms.

The condition required for stimulated emission to dominate spontaneous emission, where the energy difference between energy levels is greater than the thermal energy.

The condition where the energy difference between energy levels is equal to the thermal energy, increasing the likelihood of stimulated emission.

A method of pumping where light energy is used to excite atoms. It's commonly used in ruby lasers and many other solid-state lasers.

A pumping method that utilizes an electrical discharge to excite atoms. It is frequently used in gas lasers, such as the Argon-ion laser.

A pumping technique that uses inelastic collisions between two different types of atoms to transfer energy. One type of atom is excited with an electrical discharge, and then transfers energy to the other type of atom.

A type of pumping where electrical energy is directly converted into radiant energy. This is used in semiconductor lasers and LEDs.

A pumping method that uses the energy released from a chemical reaction to excite the active medium. For example, the reaction between hydrogen and fluorine to form hydrogen fluoride generates enough heat to pump a CO2 laser.

The material that undergoes population inversion and amplifies light through stimulated emission. It is the heart of a laser. For example: ruby crystal, helium-neon gas mixture, and semiconductor materials.

The atoms within the active medium that participate in stimulated emission, contributing to the laser action.