Laser Physics and Photon Behavior

Mr. Anderson explains stimulated emission, where photons are emitted coherently, forming a laser. He describes how atoms absorb photons to reach higher energy levels and emit identical photons when stimulated again. The process is illustrated with an energy diagram and a simulation, showing how lasers are built using mirrors to reflect photons. The video concludes with a recap of how energy level changes relate to photon absorption and emission.

What is the main characteristic of a red laser compared to regular red light?

• It emits photons of different colors.

• It emits photons coherently in the same direction.

• It emits photons in random directions.

• It emits photons with varying energy levels.

What happens during stimulated absorption?

• An atom emits two identical photons.

• An atom releases energy spontaneously.

• An atom absorbs energy and moves to a higher energy level.

• An atom remains at the same energy level.

What is the probability of an atom moving to a higher energy level without a photon?

• Very high

• Moderate

• Impossible

• Incredibly small

In stimulated emission, what occurs when an atom at a higher energy level is hit by a photon?

• The atom absorbs the photon and moves to an even higher energy level.

• The atom emits two identical photons.

• The atom remains at the same energy level.

• The atom releases energy spontaneously.

What must match exactly for an atom to be excited to a higher energy state?

• The wavelength and frequency of the photon

• The color of the photon

• The temperature of the environment

• The size of the atom

How does stimulated emission build up in a system of atoms?

• By increasing the temperature of the system

• By emitting photons in random directions

• By absorbing photons from the environment

• By reflecting photons back and forth using mirrors

What role do mirrors play in the creation of a laser?

• They change the color of the photons.

• They reflect photons back and forth to build up emission.

• They increase the energy of the photons.

• They absorb excess photons.

In the simulation, what happens when the wavelength of light is adjusted correctly?

• The atom jumps to a higher energy level and emits coherent photons.

• The atom absorbs all incoming photons.

• The atom jumps to a lower energy level.

• The atom remains at the same energy level.

What is the effect of decreasing the reflectivity of the mirror on the right in a laser setup?

• Photons are absorbed by the mirror.

• Photons are emitted in random directions.

• Photons move out coherently.

• Photons are trapped inside the laser.

What is the relationship between energy levels and photon emission in atoms?

• Changes in energy levels are tied to the absorption or emission of photons.

• Photon emission occurs only at the highest energy level.

• Photon emission is random and unrelated to energy levels.

• Energy levels do not affect photon emission.