What happens to the light waves as they exist the barreis S1 and S2?

As the light waves exit the barriers S1 and S2, they continue to propagate in a straight line until they encounter another medium or obstacle that may cause them to change direction, reflect, refract, or be absorbed. The behavior of the light waves will depend on the properties of the medium they encounter and the angle at which they strike it.

When light waves exit the slits S1 and S2, they undergo diffraction and interference.

Diffraction:

- As light waves pass through narrow slits, they spread out and bend around the edges of the slits.
- This spreading out is called diffraction.
- The amount of diffraction depends on the wavelength of light and the width of the slits.

Interference:

- When the diffracted light waves from both slits overlap, they interfere with each other.
- Constructive interference occurs when the waves are in phase and reinforce each other, resulting in bright bands on a screen.
- Destructive interference occurs when the waves are out of phase and cancel each other out, resulting in dark bands on the screen.

Interference Pattern:

- The combination of diffraction and interference creates an interference pattern on a screen placed behind the slits.
- This pattern consists of alternating bright and dark bands, with the intensity of the bands determined by the amount of interference.

Additional Effects:

- The distance between the slits and the screen affects the size and spacing of the bands.
- The wavelength of light also affects the interference pattern, with different wavelengths producing different band spacing.
- If the slits are close together, the diffraction and interference effects become more pronounced.