Impact of white light source on fringe pattern

In summary, double slit interference is a phenomenon that occurs when light passes through two narrow slits, creating a pattern of bright and dark fringes on a screen. The fringe separation can be calculated using the equation W= (Wavelength x D)/s, and in the given scenario, it is equal to 1.06mm. If the light source is replaced by a white light source, the fringe pattern would increase due to the wider range of wavelengths present.
  • #1
aurao2003
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0

Homework Statement


Hi

A little help will be appreciated



(a)Double slit interference fringes are observed using light of wavelength 590nm abd a pair of double slits of spcing o.50mm. The fringes are observed on a screen at a distance of 0.90m from the double slits. Calculate the fringe separation of these fringes.



(b)Describe and explain the fringe pattern that would be observed if the light source were replaced by a white light source



SOLUTION


Homework Equations


W= (Wavelength x D)/s





The Attempt at a Solution


I was able to do (a)



With (b) I surmised that fringe patterns would increase. White light contains a wide range of wavelengths. So, according to the above equation:

The fringe pattern is proportional to the wavelength.



Please comment.
 
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  • #2




Thank you for your question. In order to fully answer your question, let's first define what double slit interference is. Double slit interference is a phenomenon that occurs when light passes through two narrow slits that are close together. The light waves from each slit interfere with each other, creating a pattern of bright and dark fringes on a screen.

Now, let's address part (a) of your question. To calculate the fringe separation, we can use the equation you provided: W= (Wavelength x D)/s. In this equation, W represents the fringe separation, D represents the distance from the double slits to the screen, and s represents the slit spacing. Plugging in the given values, we get:

W= (590nm x 0.90m)/0.50mm = 1.06mm

Therefore, the fringe separation in this scenario would be 1.06mm.

Moving on to part (b) of your question, you are correct in stating that the fringe pattern would increase if the light source were replaced by a white light source. This is because white light is made up of a range of wavelengths, which would result in a wider range of fringe separations. This would create a more complex and colorful fringe pattern on the screen.

I hope this helps to clarify your understanding of double slit interference. If you have any further questions, please don't hesitate to ask. Keep up the good work!
 

1. How does the use of a white light source impact the fringe pattern in interferometry experiments?

The use of a white light source can significantly impact the fringe pattern in interferometry experiments by causing interference fringes to appear as colored bands instead of the expected monochromatic fringes. This is due to the fact that white light is composed of multiple wavelengths, resulting in different wavelengths interfering with each other and producing a rainbow-like effect.

2. Can the impact of a white light source on fringe pattern be mitigated?

Yes, the impact of a white light source on fringe pattern can be mitigated by using a narrowband filter to block out all but one wavelength of light. This will result in a more accurate and clear fringe pattern, as only one wavelength will be present to interfere with itself.

3. How does the coherence length of a white light source affect the fringe pattern?

The coherence length of a white light source can greatly affect the fringe pattern in interferometry experiments. A longer coherence length will result in narrower and more closely spaced fringes, while a shorter coherence length will produce wider and more widely spaced fringes.

4. Are there any advantages to using a white light source in interferometry experiments?

Yes, there are some advantages to using a white light source in interferometry experiments. For example, it allows for the measurement of multiple wavelengths simultaneously, which can be useful in certain applications. Additionally, a white light source can provide a more stable interference pattern compared to a monochromatic source.

5. What other factors should be considered when using a white light source in interferometry experiments?

When using a white light source in interferometry experiments, factors such as the angle of incidence, polarization, and surface reflectivity of the objects being measured should also be taken into consideration. These factors can affect the quality and accuracy of the interference pattern and should be carefully controlled for in order to obtain reliable results.

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