Geometrical Optics; Refraction and Dispersion

What it shows:

In quantum mechanics, it is possible for a particle to tunnel through a potential barrier because its wave function has a small but finite value in the classically forbidden region. Here we use FTIR as an optical analog of this quantum...

What it Shows

A beam of laser light can be trapped inside a stream of water by suffering total internal reflection—the aquatic equivalent of a fiber optic cable.

How it Works

A stream of water flows from a hole in the side of a soda bottle (Figure 1...

What it shows:

Light is transmitted by a bundle of optical fibers and/or a coiled length of plastic rod, regardless of the twists and turns in the path it must negotiate. Total internal reflection keeps the light confined.

How it works:

A HeNe laser is...

What it shows:

A simple qualitative demonstration of total internal reflection using a laser beam.

How it works:

Using a fish tank suitably doped with a scattering agent (see Setting it Up), a ray of light from a laser beam can probe the water-air boundary...

What it shows:

As a simulation of atmospheric refraction, this demonstration shows the gradual and continuous bending of light due to a gradient in the optical density of the medium. In this case the variable refracting medium is a tank of sugar water...

Optical technique that allows us to see small changes in the refractivity of air and other transparent media.

What it Shows

Refraction due to inhomogeneity in air is made visible by our single-mirror schlieren optics setup. The refraction can be caused...

What it shows:

There are various types of mirages possible, the details depending on whether the hot air is above or below the cool air and how sharp the transition is from cool to warm. This demonstration simulates what happens when a dark asphalt road...

What it shows:

A beam of light is distorted due to turbulent convection currents in air. This is a model of atmospheric distortion that affects seeing conditions in ground based optical and infrared astronomy.

How it works:

Turbulent air is provided by an...

What it shows:

A beam of white light incident on a giant raindrop (simulated by a water-filled round flask) produces a full rainbow of colors. As with real rainbows, one can also see that the light intensity inside the rainbow is much greater than outside...