To explain coherence in more detail, first we need to take a look at the laser beam. The “light amplification by stimulated emission of radiation” is a collective term from physics. The term laser denotes both the physical effect, i.e. the light beam, and the corresponding device (laser machine, laser source).
- Are electromagnetic waves
- Often have a very narrow frequency range (narrow-band emitter)
- Consist of a sharply focused light beam
- Have a long coherence length, depending on the type of laser
In everyday life, lasers are found in a wide variety of applications. Be it in a laser pointer, which is often used in presentations, in tools or for reading optical storage media such as Blu-rays or CDs: The laser beam is indispensable in modern life.