Methods of Light Production

what is luminous?

an object which produces visible light

ex. candle, sun, flashlight, neon light

what is non-luminous?

an object which does not produce visible light, but reflects or allows light to pass through allowing us to see the object

how many methods of light production are there?

8

name the methods of light production

Incandescence, fluorescence, electrical discharge, phosphorescence, chemiluminescence, bioluminescence, triboluminescence, light emitting diode (LED):

what is incandescence?

the production of light as a result of high temperature

ex. candle, incandescent light bulbs

what is the fluorescence?

the production of visible light when a substance absorbs UV light. Occurs and stops almost instantaneously as soon as the excitation source is removed.

ex. fluorescent light

what is electrical discharge?

the production of light by passing an electrical current through a gas

ex. aurora borealis, lightning, neon signs

what is phosphorescence?

the production of visible light after a material absorbs UV light which is emitted over an exerted period and continues to glow after the energy source is removed. the electrons are trapped in a high-energy state and only slowly return to their original state.

ex. glow in the dark stickers which contain phosphorus

what is chemiluminescence?

the direct production of light as a result of a chemical reaction where little to no heat is produced

ex. glowsticks

what is bioluminescence?

a type of chemiluminescence where light is produced in living organisms as a result of a chemical reaction with little to no heat produced

e.g. some fungi, fireflies, anglerfish, “jack-o-lantern” mushrooms, jellyfish 

what is triboluminescence?

the production of light from friction as a result of scratching or rubbing certain crystals

ex. biting on wint-O-green lifesaver, rubbing quartz crystals together, peeling sticky tape

what is Light Emitting Diode (LED)?

the production of light as a result of an electric current flowing in semiconductors

ex. christmas lights, traffic lights, electronic indicators

LED

Light Emitting Diode