Physics - Optical fibres Flashcards
What is an optical fibre made out of?
Core, Cladding, buffer, jacket.
What is the core of an optical fibre?
A long thin cylinder of glass.
What is the cladding of an optical fibre?
Glass that surrounds the core and has a lower refractive index.
What are step index fibres?
The core is surrounded by cladding that has a single uniform index of refraction.
What are graded index fibres?
The refractive index of the optical fibre decreases as the radial distance from the fibre axis increases.
What are plastic optical fibres?
Polymethylmethacrylate is used as a core material for the transmit ion of light.
What are glass fibres?
Extremely fine glass fibres.
What are single mode fibres used for?
Long distance transmission of signals.
What are multimode fibres used for?
Short distance transmission of signals.
What can optical fibres be used for?
Telephone
Medical applications
CCTV cameras
Computer networking
Internet
Defence and space related applications
Automobile industries
Television cables
What are endoscopes used for?
Allow to see inside an organ, guide surgical equipment.
How are optical fibres used in endoscopes?
Light is piped from an outside source into the optical fibres, that are connected to an objective lense, that allows for the medical professional to see.
How thin is an optical fibre?
As thin as a human hair.
Why does the resolution depend on the amount of fibres?
Each optical fibre only transmits one pixel of coloured light, the more fibres, the more pixels of coloured light.
Benefits of optical fibres in endoscopes.
Less invasive
Less chance of infection
Recovery is quicker
Flexible to travel deep within the body.
Less expensive
Can be performed on out patients (patients that do not stay the night)
