Question

Distinguish between ordinary light and laser light.

Answer 1

Hint: In order to explain this concept, we mainly give importance to the definition of energy and electromagnetic waves of different wavelengths. The light which consists of electromagnetic waves of wavelength range (400nm – 700nm).

Complete step by step solution:
Ordinary light:-
1. It is a mixture of electromagnetic waves of different wavelength
2. It is non-directional and inconsistent, which means it travels without following any direction.
3. Ordinary light has a wide spectrum of light that moves irregularly at different wavelengths.
4. Ordinary light does not contain photons of the same frequency.
5. Example for ordinary light, sunlight, fluorescent and incandescent etc.
6. The intensity of light decreases rapidly as it travels a long distance.

Laser light:-
1. Laser light is monochromatic (containing only one colour)
2. Laser light shows directional and highly consistent distribution.
3. It has a focused beam in which all photons move at the same wavelength and same direction.
4. Laser light are spectrally pure
5. Lasers have narrow frequency range and directional distribution.
6. In contrast, laser light is emitted from a narrow beam. Since energy is concentrated in a narrow area, looking at the laser light with naked eye can damage the eye.

Note: Light energy from the sun can also be harvested to electricity light energy can also be classified as different forms of energy. Also conservation law of energy says that it is neither created nor destroyed by ordinary light sources used for illumination whereas laser light used in metal cutting machines, laser printers, fibre optic technology etc.