Exploring Interference Patterns with Helium-Neon Laser Light

How can we determine the order of interference in an interference pattern?

A. By measuring the distance between the screen and the slits

B. By counting the number of bright fringes observed

C. By calculating the wavelength of the laser light used

Answer:

The order of interference in an interference pattern can be determined by counting the number of bright fringes observed on the screen. In the given scenario, twelve bright fringes indicate the twelfth order of interference.

When observing an interference pattern created by a helium-neon laser light passing through two narrow slits, the number of bright fringes on the screen serves as an indicator of the order of interference. In this case, twelve bright fringes are observed, indicating the twelfth order of interference.

The interference pattern results from the constructive and destructive interference of light waves passing through the two slits. Bright fringes are formed where the waves reinforce each other, while dark fringes occur where the waves cancel each other out. By counting the bright fringes, we can determine the order of interference.

To calculate the slit separation (d), we can use the formula d = λL / m, where λ is the wavelength of the light, L is the distance between the screen and the slits, and m is the order of interference. Substituting the given values of λ = 633 nm (or 633 × 10^-9 m), L = 3.0 m, and m = 12 into the formula allows us to find the slit separation.

Understanding interference patterns and the factors that influence them can provide valuable insights into the behavior of light waves and the principles of wave interference.