Surface plasmon polaritons enhanced random lasing and weak localization of light in un- and ZnSe-coated Nd3+ doped (Pb,La)(Zr,Ti)O3 ceramics

Abstract In this work, we demonstrated the formation of nonuniform two-dimensional electron gases (2DEGs) with visible surface plasmon polaritons' (SPPs) supportiveness in un- and ZnSe-coated Nd3+ doped (Pb,La)(Zr,Ti)O3 ceramics (Nd:PLZT), and its enhancement effect on random lasing and weak localization of light. Firstly, charge density distribution in the modified ZnSe film was calculated, revealing the formation of nonuniform 2DEGs, namely, a very thin metallized layer. In bulk samples, the excitation of SPPs contributes to the transformation from conventional lasing to random lasing, as evidenced by the dynamics. The optical whisper-gallery-like pattern was observed in a cylinder shaped Nd:PLZT, demonstrating convincingly SPPs propagating along the border owing to the polarity discontinuity. Based on this, Nd:PLZT was processed into powdered forms to increase the surface-volume ratio. Furthermore, the powdered specimen was coated with ZnSe film to further strengthen plasmonic impact. A 7.6 × enhancement in random lasing at 589 nm and three-fold reduction in threshold of weak localization of light at 684 nm were observed in the ZnSe/Nd:PLZT, by comparing to the bare Nd:PLZT. This work opens an avenue leading to SPPs’ implementation without any metal parts involved and hence presents a promising candidate for serving as nanolaser for nanophotonic circuits.