Laser Beams


The fog machine makes the beam visible.
The fog machine makes the beam visible.

A laser beam is made visible by the mist from a fog machine



Principles Illustrated

Laser beams are coherent light that is nearly monochromatic. They do spread out with distance (contrary to popular perception) but the spreading angle is very small.

NCEA & Science Curriculum

JNR SCI, SCI 1.3, SCI 2.9, PHYS 1.4, PHYS 2.3


Access to a laser beam and a fog machine.


One of our He-Ne lasers
One of our He-Ne lasers

Lasers have been in the news quite a lot lately. One can purchase really quite dangerous lasers on the internet. Be sure your laser is low power and safe, and be very careful with it.

Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.

Related Resources

Whiteboard Optics


A laser in operation in the Raman Spectroscopy lab at Victoria University
A laser in operation in the Raman Spectroscopy lab at Victoria University

LASER is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. Stimulated emission, in which a suitable photon interacts with an atom in an excited state, results in the production of a pair of essentially identical photons. To make a laser beam, you have to get the majority of atoms that produce the laser beam in the same excited state. This is called a population inversion and it is not easy to achieve.

Teaching Resources

Would you like to contribute lesson suggestions? Contact us.


This teaching resource was developed with support from

The MacDiarmid Institute
Faculty of Science, Victoria University of Wellington
School of Chemical and Physical Sciences, Victoria University of Wellington


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