Spontaneous Emission in Cylindrical Periodically-Layered Structures

Abstract

This paper studies the effects of cylindrical dielectric periodically-layered structures on spontaneous emission from an excited dipole line source. The source is modeled as a forced oscillator with radiative damping. The underlying physics lies in how the oscillator can be driven by the reflected field supported by this structure. To match the boundary conditions of EM waves, the transfer matrix method (TMM) is employed for its simplicity and versatility. Both the frequency shift and modified radiative damping rate are formulated analytically. It is shown that due to interference the wave supported by the structures can affect the source emission significantly. Strong enhancement and inhibition of the emission depend on both the layered structure and the frequency. Different compositions of the structures are achieved by tuning the structure parameters such as the reflective index and the width of layers. Furthermore, the results reveal that the strong enhancement and inhibition are sensitive to the layer width. It is found that strong inhibition is stable against source position variation, whereas strong enhancement is quite unstable. Potential applications in cylindrical quantum well lasers and semiconductor devices and perspective for future work are suggested.