Other uses of light

Question 1

What is total internal reflection?

Answer 1

As the angle of incidence increases, so does the angle of refraction

Beyond a certain angle, called the critical angle, all the waves reflect back into the glass and no refraction occurs

Question 2

What is an optical fibre?

Answer 2

thin rod of glass

light enter at one end and undergoes repeated total internal reflection

the light emerges at the other end

used in cable TV and broadband

Question 3

What is an endoscope

Answer 3

endoscope use optical fibres

doctors insert the fibres in the body

some carry light into the body and some carry light reflected from the internal surfaces in the body

used by doctors in diagnosis

Question 4

What are lasers?

Answer 4

laser produce an intense narrow beam of light

laser light has a low divergence

Question 5

What is cauterising and what is it uses in medicine?

Answer 5

using lasers to destroy damage tissue or to stop bleeding after surgery

lasers are used in eye surgery to repair damage retina or cut the cornea to correct a persons vision