# Single slit diffraction confusion

In summary, the conversation discusses the concept of interference in wave experiments, specifically in relation to dividing the slit into different parts. The speaker questions whether dividing the slit into four parts and claiming destructive interference, or dividing it into two parts for constructive interference, is the more accurate explanation. The other person explains that the simple subdivision explanation is a crude approximation and that a more accurate calculation involves considering each point of the gap as a wave source and integrating the paths' interferences.
I've found this a very confusing thing:when we locate the second dark fringes above and below the central maxima,we divide the slit into four parts and claim that pairs of waves interfere destructively as the path difference would be wavelength/2.But what if we just divided it into two parts and claimed that two rays each from one half at equal distance would always interfere constructively with path difference=wavelength?

Well, you uncovered the fact that the "simple subdivision of the gap" explanation is a very, very crude approximation. It gets the basic principle across that waves originating at different parts have different path lengths (and thus will interfere with each other), but of course, if you *really* want to calculate it, you have to consider each point of the gap as a wave source and add (well, integrate) the paths' interferences. That integral will actually give you the answer.

## 1. What is single slit diffraction?

Single slit diffraction is a phenomenon that occurs when light passes through a single narrow slit and spreads out into a pattern of bright and dark fringes. This is due to the wave nature of light, which causes it to diffract or bend around the edges of the slit.

## 2. How does single slit diffraction differ from double slit diffraction?

Single slit diffraction occurs when light passes through a single narrow slit, while double slit diffraction occurs when light passes through two parallel and equally spaced slits. The resulting diffraction patterns are different due to the number and spacing of the slits.

## 3. What is the equation for calculating the position of the bright fringes in a single slit diffraction pattern?

The equation is: y = (nλL)/d, where y is the distance from the center of the pattern to the nth bright fringe, λ is the wavelength of the light, L is the distance from the slit to the screen, and d is the width of the slit.

## 4. Why are the central bright fringe of a single slit diffraction pattern wider than the other fringes?

The central bright fringe is wider because it is the result of light waves from the entire width of the slit interfering constructively. This is known as the single-slit interference effect, which causes the central bright fringe to be twice as wide as the other fringes.

## 5. What are some real-world applications of single slit diffraction?

Single slit diffraction is used in spectroscopy to analyze the composition of materials, in microscopy to improve the resolution of images, and in the design of optical instruments such as cameras and telescopes. It is also used in diffraction gratings, which are used to separate and analyze the different wavelengths of light.

Replies
17
Views
2K
Replies
4
Views
2K
Replies
6
Views
6K
Replies
34
Views
1K
Replies
20
Views
2K
Replies
6
Views
3K
Replies
1
Views
2K
Replies
4
Views
794
Replies
4
Views
2K
Replies
4
Views
1K