Will a single photon refract?

Refraction is a collective effect involving many photons and the motion of many atoms in the medium. A single photon will go straight. Even for a classical wave, refraction only takes place in the steady state after the wave has fully penetrated the medium.

What happens when white light passes into a prism?

As light passes through a prism, it is bent, or refracted, by the angles and plane faces of the prism and each wavelength of light is refracted by a slightly different amount. As a result, all of the colors in the white light of the sun separate into the individual bands of color characteristic of a rainbow.

Does a single photon travel as a wave?

But we discover that as soon as the photon travels out into free space, the single photon spreads out into a wave that has a non-zero width and acts just like a coherent beam containing trillions of photons.

How does a single photon interfere with itself?

This single photons apparently interferes with itself. The act of observing which slit the photon passes through collapses the photons wave function, so that instead of being in a state of superposition between two interfering state, the photon will have a single definite state that cannot interfere with itself.

Can a photon be slowed down?

The photons themselves do not slow down. But their passage through a medium involves absorption by electrons and re-emission. For some materials such as water, light will slow down more than electrons will.

Why does light reflect off matter?

Reflection off metals (like a mirror) happens because electrons in the metal happen to be able to match the frequency of the light, so it bounces off. It can also happen because of a change in refractive index. This is why you see reflections off glass or off water, or other materials that are normally transparent.

Why does white light disperse in a prism?

Since different colors of light travel at different speeds, the refractive index is different for each color. As a result, when white light passes through the refracting surface of the prism, its components bend into different angles, causing the single beam of light to separate.

How do photons travel through space?

As a photon moves through space, it exhibits oscillating electric and magnetic fields, and can interact with charged particles. These interactions slow it down, and cause it to move at a speed less than the speed of light as long as they’re in a material.

Do photons always travel in a straight line?

Photons do not travel in straight lines. Quantum particles do not have trajectories as classical particles do. Photons do not propagate in all directions as a spherical wave does. Photons are not waves.

How does a single photon move?

Since electromagnetic energy is carried by photons and moves in forms of waves, does it mean that a single photon when propagating through space doesn’t follow the straight path but instead always moves up and down, up and down like a wave. The term photon belongs to the realm of quantum mechanics.

Do photons interfere with one another?

Since light itself does not have electric charge, one photon cannot directly interact with another photon. Instead, they just pass right through each other without being affected. In this process, the energy of the photon is completely transformed into the mass of the two particles.

How does a single wavelength of light spread out in a prism?

A single wavelength of light doesn’t get spread out by a prism, it just gets refracted. The spreading out of light in a prism is Chromatic dispersion. It happens because the refractive index of the glass is different at different wavelengths.

What is a photon in physics?

In physics, photons are (usually) mathematical concepts that allow easy calculations of quantum effects in electromagnetic waves. They have some rather strange properties that make them rather unsuitable for discussing experiments like yours. For one, they have strictly a single frequency.

How do we detect single photons of light?

Strictly speaking, we are not detecting single photons of light but rather single photoelectrons, liberated by the light impinging on the CCD. Nevertheless, the quantum nature of light is evident. The positions of arrival (of the photons) are random but the probabilities of arriving at certain positions are not.

What happens when a wavepacket hits a prism?

So if one of those wavepackets hits a dispersive element, like your prism, the different frequencies will disperse, both in time (the packet becomes longer) and space (the pulse defocuses). Which is probably what you would have expected from classical electromagnetism.