Measuring the wavelength of light using diffraction

In summary, the conversation discusses an experiment in which the wavelength of a laser light was measured using different methods. The use of multiple slits was found to result in more accurate measurements, potentially due to the increased visibility and precision of the interference pattern. This is similar to obtaining more accurate results when surveying a larger number of individuals.
  • #1
ScienceGirl
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This is a repost from the general physics forum, as I didn't see the homework help forum before I posted in the other place.

Anyway, I did an experiment last week in my college physics class where we measured the wavelength of a laser light using single, double, and multiple slit diffraction and diffraction grating. Using the measurements and Young's equation, we calculated the wavelength of the light. My teacher said that as we use more slits, we should get more accurate results. Can someone explain why this happens? Is is just because as you add more slits the maxima get narrower and brighter so they are easier to see and measure?
 
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  • #2
It's because the more slits you have, the more lines it makes for the same distance. If yo have 1 slit, it makes 1 line. If you have 5000 slits (and the light goes through all of them), you get about 5000 lines.

It's sort of like finding how people feel about something. If you ask 10 people, you'll get really half-assed results. If you ask 10000 people, you'll get fairly accurate results.
 
  • #3


Yes, as you add more slits, the diffraction pattern becomes more complex and the interference effects become more pronounced. This means that the bright and dark fringes become more distinct and easier to measure accurately. Additionally, with more slits, the distance between the fringes decreases, making it easier to measure small changes in the fringe positions. This leads to more precise measurements and a more accurate calculation of the wavelength using Young's equation.
 

1. How is light wavelength measured using diffraction?

Light wavelength can be measured using a technique called diffraction, which involves passing light through a narrow slit or a diffraction grating. The resulting diffraction pattern can be observed and measured to determine the wavelength of the light.

2. What is the principle behind measuring light wavelength with diffraction?

The principle behind measuring light wavelength with diffraction is based on the wave nature of light. When light passes through a narrow slit or a diffraction grating, it diffracts and creates a pattern of bright and dark fringes. The distance between these fringes can be used to calculate the wavelength of the light.

3. What are the tools needed for measuring light wavelength using diffraction?

The tools needed for measuring light wavelength using diffraction include a narrow slit or a diffraction grating, a light source, and a ruler or measuring device to measure the distance between the fringes in the diffraction pattern. A spectrometer may also be used to accurately measure the angles of diffraction.

4. Can light of any wavelength be measured using diffraction?

Yes, light of any wavelength can be measured using diffraction as long as the wavelength is within the visible range of the electromagnetic spectrum. However, for longer or shorter wavelengths, different techniques such as interferometry or spectroscopy may be used.

5. What are the applications of measuring light wavelength using diffraction?

The measurement of light wavelength using diffraction has various applications in fields such as astronomy, spectroscopy, and material science. It is also used in the development of optical instruments and devices, such as spectrometers and lasers.

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