Photon with a nonzero mass in a centrifuge

The mass of a photon is defined as the coefficient of proportionality in the expression for the centripetal force which appears during propagation of an electromagnetic wave along a waveguide bent to form a circular arc. It is shown that this mass is identical with the quantity found earlier and equal to the energy of a photon of critical frequency divided by the square of the velocity of light. This is one more piece of evidence of the universal nature of the photon mass in spatially confined wave fields.