Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. FYI: A laser is a device that produces a very focused beam of light of just one wavelength and color. Laser light is produced in a tube. Electrons in a material such as a ruby crystal are stimulated to radiate photons of light of one wavelength. There are mirrors at the ends of the tube, and the photons of light bounce back and... Show more

Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light.

FYI: A laser is a device that produces a very focused beam of light of just one wavelength and color. Laser light is produced in a tube. Electrons in a material such as a ruby crystal are stimulated to radiate photons of light of one wavelength. There are mirrors at the ends of the tube, and the photons of light bounce back and forth off the mirrors.    
This focuses the light, causing the crests and troughs of the waves to line up. The mirror at one end of the tube is partly transparent. A constant stream of photons passes through the transparent part, forming the laser beam.    
Laser light has many uses. For example, it is used to scan bar codes and to carry communication signals in optical fibers. Optical fibers are extremely thin glass tubes that are used to guide laser light. Sounds or pictures are encoded in pulses of laser light, which are then sent through an optical fiber. Optical fibers are used to carry telephone, cable TV, and Internet signals.    

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