Resonance energy transfer between two axially oriented atoms near a finite optical fiber

Abstract We derive a formula for computing the resonance energy transfer (RET) rate between two two-level atoms—one in the excited state (donor) and the other in the ground state (acceptor)—oriented along the axial direction near a finite-length dielectric cylinder, which can be regarded as a finite optical fiber. By employing a truncated Born expansion of the homogeneous Green’s tensor and using numerical solutions, we identify a range of parameters for which the finite cylinder can be well approximated by an infinite one, whose Green’s tensor is known in closed form. Beyond the validity of the infinite-cylinder approximation, we find that the effect of the fiber tip on the RET rate becomes significant, particularly when the donor–acceptor pair is located above the top edge of the fiber.