3358. The first step to getting output from a laser is to excite an active medium. What is this process called?

✅ The correct answer is option A.
A collection of atoms or molecules that can be excited to a higher energy state is called an active medium. Before lasing can occur, the active media is “pumped”. The process of raising the atoms in the active media from a lower energy state to a higher state is like pumping water up from a well.