P. Tournois, NEGATIVE GROUP DELAY TIMES IN FRUSTRATED GIRES-TOURNOIS AND FABRY-PEROT INTERFEROMETERS, IEEE journal of quantum electronics, 33(4), 1997, pp. 519-526
It is demonstrated in this paper that a Gires-Tournois interferometer
illuminated with an angle of incidence greater than the critical angle
for total internal reflection introduces a negative group delay time,
whatever the orientation of the electric field vector of the wave wit
h respect to the plane of incidence, when the evanescent wave in the d
ielectric layer is reflected by a dielectric substrate whose refractiv
e index is between those of the incident medium and of the dielectric
layer, When the evanescent wave in the dielectric layer is reflected b
y a nonabsorbing metal, the group delay time is negative when the elec
tric field vector is in the plane of incidence and positive when the e
lectric field vector is perpendicular to the plane of incidence, Simil
arly, a frustrated Fabry-Perot interferometer shows negative group del
ay times for angles of incidence greater than specific p-wave and s-wa
ve critical angles.