1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Diffraction from Sub-Wavelength Features

  1. Sep 4, 2011 #1
    I was wondering what occurs when a diffraction grating is produced with features smaller than a wavelength of visible light. If the pits in a CD were made to be only a few tens of nanometers wide, what would we see?
     
  2. jcsd
  3. Sep 5, 2011 #2
    The minimum intensity occurs at angles given from the following law:[itex]d\sin\theta_{min}=\lambda\approx \theta_{min}=\frac{\lambda}{d}[/itex]
    So, if [tex]d <<\lambda[/tex], then [tex]\theta_{min}[/tex] becomes great: you can't see any minimum of diffraction.
     
    Last edited: Sep 5, 2011
  4. Sep 5, 2011 #3

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor
    2016 Award

    It entirely depends on the details- pit spacing, etc. Subwavelength apertures produce evanesecent field modes. People have been trying to exploit that property for super-resolution imaging.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook