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.


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.

  • $\begingroup$ 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

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