A Metastable State Is Important for the Generation of a Laser

question 8

Multiple Choice

A metastable state is important for the generation of a laser beam because it assures that:

• A)spontaneous emission does not occur more often than stimulated emission
• B)photons do not split too rapidly
• C)more photons are emitted than are absorbed
• D)photons do not collide with each other
• E)photons do not make upward transitions

---

Definitions:

Volcanic Ash

Fine particles of pulverized rock ejected from a volcano during an eruption, can cause damage to aircraft and affect climate.

Welded Igneous Texture

Characteristic of volcanic rock that forms when hot volcanic ash and debris fuse together under high temperature and pressure.

Magma

Molten rock beneath the Earth's surface, which can cool and solidify to form igneous rocks.

Pyroclastic Eruption

A volcanic eruption where hot fragments and magma are thrown into the air; also refers to a deposit or rock produced by such an event.