Fluorescence is the property or the ability of certain substances that allow them to absorb a certain set of wavelengths and emit radiations into the environment that belong to a different set of wavelengths. The phenomenon of fluorescence generally takes place when the atoms of a certain element get excited by absorbing a significant amount of energy. The excited state of the atoms is highly unstable in nature, which is why they soon undergo a loss in energy and return back to the ground state from the excited state. The loss of energy leads to the emission of photons into the surroundings that cause the radiation of light energy. Most of the time, the fluorescent pigments stop glowing when the light source is removed. Unlike phosphorescent objects, in the case of fluorescent objects, the light radiations get emitted into the environment right after the absorption of radiations or energy particles take place.
Examples of Fluorescence
The fluorescence property of materials is used in a number of daily life applications. A few of them are listed below:
1. Rhodamine B
Rhodamine B is one of the most prominent examples of the fluorescence phenomenon in real life. Rhodamine B is nothing but a chemical compound that tends to radiate light energy into the surroundings when it is mixed with water.
The highlighters that are typically used in our daily life to mark important stuff written in books and notebooks is yet another application of the fluorescence phenomenon in real life. The ink contained by a highlighter pen is nothing but fluorescent ink.
3. Household Decorative Items
A variety of substances used in households for decorative purposes make use of the concept of fluorescence.
A variety of glowing toys such as glow sticks, light-emitting swords, etc. make use of the fluorescence of certain chemical substances to emit light energy into the surroundings.
A variety of accessories such as wrist bands, goggles, headbands, etc. contain chemicals in them that tend to emit light radiations into the environment after absorbing electromagnetic radiations. Here, the conversion of chemical energy into light energy due to the absorption of radiations can be observed easily. Such types of accessories are usually used in parties and celebratory functions.
6. Compact Fluorescent Lamps
A compact fluorescent lamp is a type of artificial source of light that typically makes use of the fluorescence phenomenon to emit light into the environment. A compact fluorescent lamp or a CFL typically consists of a mixture of argon and a comparatively small amount of mercury vapour in its internal structure. When an electric current is made to flow through the CFL, a significant amount of ultraviolet light gets generated. The ultraviolet light is not visible to naked eyes and is further used to excite the coating of fluorescent material present on the inner side of the lamp, thereby emitting light energy into the environment. The fluorescent material typically preferred for the inner coating of the lamp is phosphor.
7. Fluorescent Colours
The fluorescent colours find their prime application in the clothes and textile industries. The fluorescent clothes, shoes, and other products are able to produce a glowing effect by absorbing the light energy or radiations that fall into a relatively narrow band of wavelength and emitting the light energy or radiations with comparatively longer wavelengths.