1
$\begingroup$

If I have a gamma photon traveling in air and it shoots off towards a glass mirror and bounces off it, when I measure its phase, will it have changed by 180${}^\circ$?

I was reading the wikipedia article on reflection phase change and it says

Light waves change phase by 180° when they reflect from the surface of a medium with higher refractive index than that of the medium in which they are travelling. A light wave travelling in air that is reflected by a glass barrier will undergo a 180° phase change [...]

But I didn't know if wavelength of the photon changes that.

$\endgroup$
1
$\begingroup$

This effect is independent of wavelength, as long two things hold:

  • The refractive index of the substance does not become less than that of the incident medium at any wavelength; and

  • The reflectivity of the substance is sufficiently high at all wavelengths that reflection can actually be detected.

$\endgroup$
  • $\begingroup$ Practically, is there a way to detect the phase of a gamma photon? $\endgroup$ – The Photon Jul 18 '17 at 21:05
  • $\begingroup$ Considering their frequencies are on the order of $10^{19}$ Hz, and our best timing devices are only accurate to 1 part in $10^{18}$, probably not directly. That said, detecting the relative phase of two gamma rays is simple - just have them interfere and measure the amplitude. $\endgroup$ – probably_someone Jul 18 '17 at 21:08
  • $\begingroup$ Are there coherent sources for gamma rays? The Wikipedia article on grasers implies they're hypothetical. $\endgroup$ – The Photon Jul 18 '17 at 21:10
  • $\begingroup$ Electron synchrotron radiation in extremely high magnetic fields could produce coherent gamma rays: link.springer.com/chapter/10.1007/1-4020-3881-X_31 $\endgroup$ – probably_someone Jul 18 '17 at 21:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.