refraction. reflection & refraction refraction air – lower refractive index water – higher...
TRANSCRIPT
Refraction
Reflection & Refraction
Refraction
Air – lower refractive index
Water – higher refractive index
The Kingfisher•When light is passing from a higher refractive substance into a lower refractive substance the light rays bend away from the perpendicular to the surface.
perpendicular
Refraction
Air – lower refractive index
Water – higher refractive index
The Fish•When light is passing from a lower refractive substance into a higher refractive substance the light rays bend toward the perpendicular to the surface.
perpendicular
Refraction
Air – lower refractive index
Glass – higher refractive index
Glass Window
Air – lower refractive index
Refraction
•Light passing through a transparent material exits at the same angle it enters
Lens
ApplicationRefraction
Total Internal ReflectionTotal Internal Reflection
• Can occur when light inside glass block hits the edge at
certain angles
• As you increase the angle the ray gets bent
• However – at a particular angle called the Critical Angle
something strange happens
TOTAL INTERNAL REFLECTION OF LIGHT
NINCIDENT RAY
REFRACTED RAY
The ray is refracted parallel to the edge of the block at the
Critical angle
As we increase the angle of As we increase the angle of incidenceincidence
• As the angle of incidence increases, the ray is now only reflected back inside the block
• The edge of the block acts like a mirror• The ray does not pass out of the block• This is total internal reflection
So the 600 angle has total internal reflection
Internal ReflectionInternal Reflection• This occurs only when light travels from
more dense to less dense media.
AppplicationsAppplications• Fibre optics
– Communication– Lighting– Endoscopy