What is Fluorescence?

• Fluorescence is a type of luminescence, occurs in gas, liquid or solid chemical systems.

• Fluorescence’s energy is supplied by the electromagnetic radiation, usually the ultraviolet light.

• Fluorescence is an optical phenomenon in which a molecule absorbs a high-energy photon, and re-emits it as a lower-energy (longer-wavelength) photon, the energy difference between the absorbed and emitted photons ending up as molecular vibrations (heat). Usually the absorbed photon is in the ultraviolet, and the emitted light (luminescence) is in the visible range.

Physics Equations

• S0+hvex=S1

• S0 is the ground state of the fluorophore and S1 is its first electronically excited state. hv is energy where the h is Planc’s constant which is a physical constant that is the quantum of action in quantum mechanics and v is the frequency of lights. So hvex is the energy of absorbed light. Which would resulted;

• S1 = S0 + hvem + heat/ vibration

*hvem is the emision light

Fluorescent Light

• The light glass contains a small bit of mercury and inert gas (argon).

• Phosphor powder coated all along the inner glass surface.

• So first, after we turned on the light, electrode produce electrons.

• These electrons will be transferred to the other electrode by the inert gas.

• This energy will change mercury into a gas.

• Some of the electrons around the tubes will be collide with the mercury gas and create a high energy level.

• When the electrons fall back to its original level, the atom would create an extra energy in form of UV photon.

Fluorescence in Nature

• Fluorescence is not only found in light bulb but also in nature. For example, there are types of calcites that could fluoresce under short-wave UV light such as Ruby, Emerald and Hope Diamond. Diamond would fluoresce in under X-Ray.

Another Uses of Fluorescence

• Fluorescence Spectroscopy

• Biochemistry and Medicine

• Microscopy

Work Citation

• Harris, Tom (May 5,2014). Fluorescence, How Fluorescent Lamp Works. http://home.howstuffworks.com/fluorescent-lamp2.htm

• http://encyclopedia.kids.net.au/page/fl/Fluorescence