High Q/V hybrid plasmonic photonic crystal nanobeam cavity: Towards low threshold nanolasers application

In this paper, we investigate a hybrid plasmonic photonic crystal nanobeam cavity with the low-index slot layer sandwiched between a metallic layer and a high-index layer. The cavity with ultrahigh Q/V can be achieved since the photon energy is well confined in the low index slot layer. By using quantum dots (QDs)-polymer as the active medium for the low-index slot layer, we demonstrate numerically that such hybrid laser structure has a gain threshold as low as gth=374 cm−1, while maintaining an ultrasmall subwavelength mode volume of 0.0756 (λ/n)3.