In a few words, explain what Total Internal Reflection is?
When light traveling from a lower refraction index material (like glass) to a higher refraction index material (like air), it is refracted away from the normal. Total Internal Reflection (TIR) is when light is reflected from the boundary as if it is a mirror.
Total Internal Reflection
Critical angle: At an angle of incidence called the critical angle, light is refracted so far from the normal that it runs along the boundary of the two substances. For any angles of incidence greater than this, there is no refracted ray.
Concepts:
Total Internal Reflection can be used to make glass appear invisible when viewed from a certain angle. Total Internal Reflection is used in fiber optics and can be used to transmit data over long distances without signal loss. It also explains why diamonds sparkle.
Did you know?
Brain break: Draw a dinosaur wearing a bow-tie and a top hat, holding an ice-cream cone.
A lens is a transparent piece of plastic, glass or even jelly that is shaped to curve outwards or inwards. A lens refracts light and focuses it to form images in the eye and in devices such as cameras, telescopes, binoculars, microscopes, spectacles and contact lenses.
Lenses
A lens that bulges outwards is called a convex lens. These lenses cause light rays to come together, or converge. If a convex lens is held close to an object, it can be used as a magnifying glass. In this case, it produces an upright and enlarged (magnified) virtual image.
Convex Lenses
When light reaches a convex lens from a distance, the convex lens can be used to focus the light on a screen to form an image. Light is focused to a point on a screen when you see a film at the movies. This is the type of image that is formed by the convex lenses in your eyes. This type of image is called a
A lens that curves inwards is called a concave lens. These lenses cause light to diverge, or spread out. They spread parallel light rays as though the rays have come from a point behind the lens. A concave lens only produces images that are smaller, upright and virtual. Because this image is virtual, we could not produce the image on a screen because the light does not really cross at this point.
Concave Lenses
What is total internal reflection?
- The refraction of light when passing from one medium to another
- The complete reflection of a light ray within a medium
- The partial reflection of a light ray within a medium
What is the critical angle?
- The angle at which total internal reflection occurs
- The angle at which refraction occurs
- The angle at which diffraction occurs
Which law governs total internal reflection?
- Snell's Law
- Newton's Law
- Einstein's Theory
In which optical device does total internal reflection play an important role?
- Telescopes
- Fiber optic cables
- Sunglasses
What is the main advantage of using Total Internal Reflection in fiber optic communication?
- Provides higher bandwidth compared to other transmission mediums
- Allows for longer cable lengths without signal degradation
- Minimizes signal loss due to absorption and scattering