Calculating Light Intensity in Diffraction Orders

• u0362565
In summary, the intensity of light produced by diffraction orders is proportional to the square of the amplitude of the wave.
u0362565
Hi,

I was wondering how you can calculate the intensity of light produced by diffraction orders. If say a laser was incident on a diffraction grating and this split the zeroth and +-1 orders what percentage of the light intensity is within the zero and first orders and how can you work this out? I'm only looking for a rough percentage figure i don't actually need to calculate exact figures, i imagine that is possible if details of the grating/laser were known..

Many thanks

No i don't think i can, i know the power at the output of the laser cavity and the wavelength but I'm not sure how i could calculate the amplitude. However if the laser incident on the grating is only split into zero and +-1 orders and that constitutes 100% of the light then there isn't a general rule of thumb for what approximate light intensity percentage the zeroth would contribute relative to the -+1 orders?
Thanks

That's interesting I've not come across blazing before, I think I need more specific info about the grating to work this out, the grating transmits multiple wavelengths so perhaps the blaze angle is optimised for one wavelength only and the rest are a compromise.
Thanks

You can calculate the interference pattern, then you square the amplitude of the wave of the point you want. There are very good videos on youtube that teach how to do that. Search for single slit diffraction and double.
Sorry I cannot help more, I am very very busy right now =(

Ok thanks i'll take a look. Thanks for your help!

What is the formula for calculating light intensity in diffraction orders?

The formula for calculating light intensity in diffraction orders is I = (sin(θ)/θ)^2, where I is the intensity, θ is the angle of diffraction, and n is the order of diffraction.

How do I determine the angle of diffraction for a specific order?

To determine the angle of diffraction for a specific order, you can use the formula θ = nλ/d, where θ is the angle of diffraction, n is the order of diffraction, λ is the wavelength of light, and d is the distance between the diffracting object and the screen.

What is the relationship between light intensity and order of diffraction?

The relationship between light intensity and order of diffraction is inverse. As the order of diffraction increases, the light intensity decreases.

Can light intensity in diffraction orders be negative?

No, light intensity in diffraction orders cannot be negative. It is always a positive value.

How does changing the wavelength of light affect the intensity in diffraction orders?

Changing the wavelength of light will change the angle of diffraction and therefore impact the intensity in diffraction orders. A shorter wavelength will result in a larger angle of diffraction and a lower intensity, while a longer wavelength will result in a smaller angle of diffraction and a higher intensity.

Replies
8
Views
1K
Replies
15
Views
5K
Replies
7
Views
1K
Replies
1
Views
1K
Replies
17
Views
2K
Replies
17
Views
3K
Replies
6
Views
6K
Replies
26
Views
9K
Replies
18
Views
8K
Replies
11
Views
2K