Calculating Wavelength of Laser Beam using Single Slit

In summary, a laser beam with a width of 0.0186 mm passes through a single slit and produces an intensity distribution pattern on a screen 105.6 cm away. The spacing between the minima on either side of the central maximum is 7.16 cm, which is represented as 2y1 in Figure 13b (page 208). Using the equations E=hc/wavelength and wavelength=c/f, the wavelength of the light can be calculated. For further information on calculating intensity of laser beams, refer to the provided link.
  • #1
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A laser beam passes through a single slit of width 0.0186 mm and produces a pattern with an intensity distribution like that shown in Figure 13a (page 208), on a screen 105.6 cm away. If the spacing between the minima on either side of the central maximum is 7.16 cm (in other words, 2y1 in Figure 13b, page 208), the wavelength of the light is ? nm.

I have absolutely no idea how to start this problem. I know that i read something in my textbook about how with intensity of laser beams need to be calculated thru E

wavelength=c/f

E=hf

E=hc/wavelength

h=6.63E-34

but I did not know if I had to/how to use these equations in this problem.
 

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I would first identify the relevant equations and principles that apply to this problem. In this case, the equation for calculating the wavelength of light is relevant, as well as the principles of diffraction and interference.

Next, I would carefully read the information given in the problem and identify the known values and the unknown value that needs to be calculated. In this case, the known values are the width of the slit (0.0186 mm), the distance to the screen (105.6 cm), and the spacing between the minima (7.16 cm). The unknown value is the wavelength of the light.

To solve for the wavelength, I would use the equation for the spacing between the minima, which is given as 2y1 in Figure 13b. This equation is:

2y1 = (λD)/w

where λ is the wavelength, D is the distance to the screen, and w is the width of the slit.

Substituting the known values into this equation, we get:

7.16 cm = (λ * 105.6 cm)/0.0186 mm

Solving for λ, we get:

λ = (7.16 cm * 0.0186 mm)/105.6 cm = 0.0012636 mm = 1.2636 μm

Therefore, the wavelength of the light is 1.2636 micrometers or 1263.6 nanometers.

In conclusion, the calculation of the wavelength of a laser beam passing through a single slit involves using the principles of diffraction and interference and the relevant equations to solve for the unknown value.
 

1. How is the wavelength of a laser beam calculated using a single slit?

The wavelength of a laser beam can be calculated using the single slit diffraction equation: λ = (a sinθ)/m, where λ is the wavelength, a is the width of the slit, θ is the angle of diffraction, and m is the order of the diffraction maximum.

2. What is the significance of a single slit in calculating the wavelength of a laser beam?

A single slit is used in the diffraction of laser beams because it produces a single, clear diffraction pattern, making it easier to measure the angle of diffraction. This allows for a more accurate calculation of the wavelength.

3. How does the angle of diffraction affect the calculation of the wavelength?

The angle of diffraction is directly proportional to the wavelength of the laser beam. As the angle of diffraction increases, the wavelength also increases. This relationship is described by the diffraction equation: λ = (a sinθ)/m.

4. Can the width of the slit affect the accuracy of the calculated wavelength?

Yes, the width of the slit can affect the accuracy of the calculated wavelength. A smaller slit width produces a wider diffraction pattern, making it more difficult to accurately measure the angle of diffraction. It is important to use a slit width that is small enough to produce a clear diffraction pattern, but not so small that it becomes difficult to measure the angle of diffraction.

5. What is the order of diffraction and how does it impact the calculation of the wavelength?

The order of diffraction refers to the number of bright spots or maxima that are observed in the diffraction pattern. The first order maximum is the central bright spot, followed by the second order maximum, third order maximum, and so on. The order of diffraction is represented by the variable m in the diffraction equation: λ = (a sinθ)/m. As the order of diffraction increases, the angle of diffraction also increases, resulting in a longer calculated wavelength.

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