Fibre Optics
What is Total Internal Reflection ?
What is Total Internal Reflection ?
When light hits the flat side of a triangular prism, the following diagram gives the three possible outcomes for the incident ray of light:-
When light hits the flat side of a triangular prism, the following diagram gives the three possible outcomes for the incident ray of light:-
- If the angle is small, 'Refraction' happens and the light leaves the block.
- If the angle is large, 'Total Internal Reflection' happens and the light stays within the block.
The 'critcal angle' is the angle at which the light changes from refracting to reflecting.
The 'critcal angle' is the angle at which the light changes from refracting to reflecting.
Fibre Optics
Fibre Optics
An optical fibre is made of two types of glass, with a dense glass core and a less dense outer cladding. When light enters the end of the fibre, it cannot escape and due to Total Internal Reflection, is reflected down the fibre.
An optical fibre is made of two types of glass, with a dense glass core and a less dense outer cladding. When light enters the end of the fibre, it cannot escape and due to Total Internal Reflection, is reflected down the fibre.
Uses of Fibre Optics : Endoscopy
Uses of Fibre Optics : Endoscopy
An endoscopy is a medical procedure that allows a doctor to examine the inside of the body using a long, flexible tube called an endoscope.
An endoscopy is a medical procedure that allows a doctor to examine the inside of the body using a long, flexible tube called an endoscope.
Using an endoscope to examine the inside of the body means that doctors can see and work inside the body, without having to cut the area open, which reduces the risk of infection.
Using an endoscope to examine the inside of the body means that doctors can see and work inside the body, without having to cut the area open, which reduces the risk of infection.
If an incision needs to be made, it can be made smaller than if an endoscope is not used, which reduces the recovery time.
If an incision needs to be made, it can be made smaller than if an endoscope is not used, which reduces the recovery time.
In an endoscope, optical fibres are used to carry light into the body to illuminate the area, then a second set of optical fibres carries the light back out to an eyepiece so the doctor can observe the area.
In an endoscope, optical fibres are used to carry light into the body to illuminate the area, then a second set of optical fibres carries the light back out to an eyepiece so the doctor can observe the area.
An endoscope has a range of tools such as grippers, cutting tools and lasers that allows them to perform surgury through the endoscope.
An endoscope has a range of tools such as grippers, cutting tools and lasers that allows them to perform surgury through the endoscope.
Uses of Fibre Optics : Internet communication
Uses of Fibre Optics : Internet communication
Fibre-optic broadband is able to provide much faster internet speeds because its cables use pulses of light (hence the word 'optic') to transmit data instead of electrical signals, which copper cables use.
Fibre-optic broadband is able to provide much faster internet speeds because its cables use pulses of light (hence the word 'optic') to transmit data instead of electrical signals, which copper cables use.
More data can fit into these light pulses than the electrical signals transmitted on copper cables. So that means more data is being transmitted per second, which means the internet speed is faster.
More data can fit into these light pulses than the electrical signals transmitted on copper cables. So that means more data is being transmitted per second, which means the internet speed is faster.
The electrical signal is converted into light pulses, which travel down the optical fibre through 'Total Internal Reflection' and are detected by sensors at the other end, which convert the light back into an electrical signal.
The electrical signal is converted into light pulses, which travel down the optical fibre through 'Total Internal Reflection' and are detected by sensors at the other end, which convert the light back into an electrical signal.