Citing some references from certain authors, light can be defined as "not only visible electromagnetic radiation, but also infrared and ultraviolet. Theories about the nature of light are, in general, very complicated. For our immediate purposes, it will be sufficient to know that light is an electromagnetic wave" [1]. And although it may sound a bit confusing, here we will explain more about it.
Light is a type of energy that travels in the form of waves, at a constant speed of 299,792,458 meters per second in a vacuum. To get an idea of this speed, if a beam of light (with sufficient power) is sent from Earth to the Moon, it would arrive in approximately 1.28 seconds, since the distance from Earth to the Moon is 384,400,000 meters.
In addition to light, there are various forms of electromagnetic radiation in the universe that propagate through space and transport energy from one place to another, such as microwaves or X-rays. These cannot be perceived by the human eye. To get an idea, we can observe in image 1 what is known as the electromagnetic spectrum, which gives us a reference of how energy is distributed, its main characteristics, and which region we can see with our eyes.
Electromagnetic spectrum
Light can be appreciated in various forms, some very different from each other, but all determined by their wavelength. This is the distance between the peak of one wave and the peak of another, as shown in the following image:
Wavelength
Visible light is a small part of the electromagnetic spectrum that can be detected by the human eye. The visible wavelengths for humans occupy a very narrow band, from 700 nanometers (nm; billionths of a meter) for red light to 400 nm for violet light, as shown in the following image:
Wavelengths of visible light
If an object can emit its own light, this object is called a light source. For example: the sun, a flashlight, a star, a light bulb, candles.
Relationship between fiber optics and light
Currently, fiber optics are used by many telecommunications companies for transmitting telephone signals, internet communication, and cable television signals. This is due to the great advantages this transmission medium possesses. Fiber optic communication is a method of transmitting information that travels from one place to another by emitting pulses of light through this medium.
Optical communication systems operate in the infrared light band (in the range of 850 to 1650 nm) produced by photoelectronic transducers that convert the electrical signal into a luminous one by means of light-emitting diodes (LEDs) or a laser diode.
References >
[1] Daniel Malacara. (2015). Basic Optics. Mexico: Fondo de Cultura Económica.
