Spontaneous emission control in high-extraction efficiency plasmonic crystals

TL;DR

This study demonstrates how plasmonic crystals can significantly enhance and control spontaneous emission in quantum wells, with potential applications in lasers, photodetectors, and biosensors.

Contribution

The paper provides both experimental and theoretical insights into exciton-SPP coupling in hexagonal plasmonic crystals, revealing high emission efficiency and mode redirection.

Findings

Radiative decay time reduced by a factor of 2.9-3.7.

80% of enhanced PL emitted into SPP modes.

17% of luminescence redirected into WC-anti-symmetric modes.

Abstract

We experimentally and theoretically investigate exciton-field coupling for the surface plasmon polariton (SPP) in waveguide-confined (WC) anti-symmetric modes of hexagonal plasmonic crystals in InP-TiO-Au-TiO-Si heterostructures. The radiative decay time of the InP-based transverse magnetic (TM)-strained multi-quantum well (MQW) coupled to the SPP modes is observed to be 2.9-3.7 times shorter than that of a bare MQW wafer. Theoretically we find that 80 % of the enhanced PL is emitted into SPP modes, and 17 % of the enhanced luminescence is redirected into WC-anti-symmetric modes. In addition to the direct coupling of the excitons to the plasmonic modes, this demonstration is also useful for the development of high-temperature SPP lasers, the development of highly integrated photo-electrical devices, or miniaturized biosensors.