1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Gouy Phase Shift

  1. Apr 18, 2012 #1
    Hello friends,
    Could you please explain me Gouy Phase Shift, i have gone through the wikipedia article and i know that it occurs because of the focusing although i am not able to get a physical picture of the same, so it would be really nice if anyone can explain me in simple words about this phenomenon.

  2. jcsd
  3. Apr 18, 2012 #2


    User Avatar
    Science Advisor

    That's a general phenomenon occuring at caustics. Usually, it is a good approximation to assume that the wave is a plane wave with wavevector given as k=nw/c, where w is the frequency, n the refractive index and c the speed of light in vacuum. Usually the intensity of that wave A varies slowly on a scale 1/k. This assumption breaks down near a caustic or a focal point and the intensity becomes very large over a distance [itex]\Delta x\approx \lambda/2=\pi/k[/itex]. This intensity bump thus shifts the phase of the wave after the focal point.
    A more careful analysis starts from the short wavelength asymptotics of the wave equation (WKB approximation), see e.g.:

    http://books.google.de/books?id=phb...wBzgo#v=onepage&q=caustic phase shift&f=false
  4. Apr 21, 2012 #3
    Thank you for your reply.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Gouy Phase Shift Date
I Phase differences in Transformers Tuesday at 12:03 PM
I EM waves in phase and E/B = c question Mar 1, 2018
B Doppler shift (red and blue) Feb 23, 2018
B Phase difference in a transformer Feb 9, 2018
I Stray/Parasitic Capacitance - Impacts phase velocity? Dec 3, 2017