What is the Separation of Two Apertures in a Light Diffraction Grating?

AI Thread Summary
The discussion focuses on calculating the separation of two apertures in a light diffraction grating setup, where light creates an intensity distribution pattern on a screen. The central bright fringe is identified as the zeroth order maximum (m=0), while the second order maximum occurs at point P, suggesting m should equal 2. The relevant equation dsinθm = mλ is highlighted, with the wavelength of light given as 600nm, L as 2m, and Y as 5cm. There is confusion regarding the value of m and how to apply the wavelength in the calculation. Clarification on these points is sought to proceed with solving the problem.
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Homework Statement


A source of light shines through two apertures resulting in an intensity distribution pattern on a viewing screen.

The central bright fringe is called the m=0 or zeroth order maximum.

In the schematic diagram 1, the light source is to the left of the page and the point P represents the position of the second order intensity maximum on the screen. Two rays r1 and r2 are depicted incident at P.

Calculate the separation d of the two apertures, given the wavelength of the light is 600nm, L = 2m, Y = 5cm.
Remember that δ is the path difference between the rays (vectors) r1 and r2.

Hint: We need to be able to relate δ to the order number and the wavelength of the light.



Homework Equations


Diagram_1.png


Diagram_2.png


The Attempt at a Solution


From wikipedia it says that dsinθm = mλ
I assume I need mλ to find out separation d of the two apertures.
λ = 600nm, L = 2m, Y = 5cm
m = 0
I'm not sure how to comprehend the wavelength.
I really need someone to explain what I need to do here.
Any help would be grand!
 
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Check you understand what "m" is in this equation..

dsinθm = mλ

Then check what value "m" is when...

point P represents the position of the second order intensity maximum
 
Ahh second order, I had m = 0 which is zeroth order.
So m should equal 2?
 

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