The Invention of Optical Fiber

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Light is everywhere, this is not
exaggerated. In the early days of human development, humans have begun to use
light to transmit information. There are many examples.

 

Gesturing is a form of visual
communication that cannot be performed in the dark. During the day, the sun
serves as the light source for this transmission system. The solar radiation
carries the information of the sender to the receiver, the movement of the hand
modulates the light waves, and the human eye acts as a detector. In addition,
beacon towers that existed more than 3,000 years ago can still be regarded as
the original form of optical communication. The emergence of the telescope has
greatly extended the distance of this type of visual optical
communication.

 

One day in 1870, British physicist
Tyndall went to the lecture hall of the Royal Society to talk about the
principle of total reflection of light. He did a simple experiment: drill a
hole in a wooden bucket filled with water, and then use a lamp to pull Water
illuminates. The results surprised the audience. People saw that the shining
water flowed out of the small holes in the bucket, the water flow was curved,
and the light followed it, and the light was captured by the curved water.

 

These phenomena attracted Ding Daer’s
attention. After his research, he found that this is the effect of total
reflection, that is, when the light is incident from the water to the air, when
the incident angle is greater than a certain angle, the refracted light
disappears, and all the light is reflected back into the water. On the surface,
light seems to bend in the current. In fact, in a curved stream of water, light
still travels in a straight line, but multiple total reflections occur on the
inner surface, and the light propagates forward after multiple total
reflections.

 

Later, people created a kind of glass
fiber with high transparency and thickness like spider silk. When the light
enters the glass fiber at an appropriate angle, the light advances along the
curved glass fiber. Because this fiber can be used to transmit light, it is
called an optical fiber.