Order of Diffraction Explained: Animation & Detailed Explanation

[dima_tr]

Hi.

I cannot understand what the order of diffraction means.

Could anybody give me some link with animation or detailed explanation?

I do not understand why it should be integer to create constructive interference?

 

[Andy Resnick]

Diffraction order can refer to a couple concepts. In dispersive optical systems (e.g. a spectrometer), light diffracting off a grating is split into multiple orders (or rainbows) because if sin(x) is a solution to the scattering problem, so is sin(2x) and sin(3x), etc.

Section 2.2 may be relevant to you:
http://gratings.newport.com/information/handbook/chapter2.asp

 

[Redbelly98]

A simple answer is: to have constructive interference, the path difference of adjacent "rays" must be an integer multiple of the wavelength. Whatever that multiple is, is the order.

See http://www.cdli.ca/courses/phys2204/unit04_org02_ilo15/b_activity.html , which has this figure:

[PLAIN]http://www.cdli.ca/courses/phys2204/unit04_org02_ilo15/les-14-01.gif[/CENTER]

p.s. Welcome to Physics Forums, dima_tr​

 

[dima_tr]

Thanks a lot.

It appears to be really simple :)