Milady Esthetics State Board Practice Test

Which of the following is a medium commonly used with lasers?

1. Liquid

2. Solid

3. Gas

4. Plasma

The correct answer is: Gas

Lasers operate by producing a concentrated beam of light through a process known as stimulated emission. The medium used in lasers is critical for this process, as it is responsible for amplifying the light and enabling the laser's operation. In the context of lasers, a gas medium is commonly employed, especially in gas lasers such as helium-neon and carbon dioxide lasers. Gas lasers function by a process where an electrical current excites the gas atoms, which then emit photons in a coherent beam. The unique properties of gas as a medium allow for efficient light amplification and high precision in applications, making it widely used in various fields, including medical esthetics. While liquids and solids can also serve as mediums in specific types of lasers (like dye lasers for liquids or solid-state lasers), the question specifically asks for a commonly used medium, and gas lasers are among the most recognized and used types. Plasma, while related to gas in terms of state, is not typically classified as a medium for standard laser operations.