Low‐Threshold Multiwavelength Plasmonic Nanolasing in an “H”‐Shape Cavity

Abstract

Multiwavelength plasmonic nanolasers are central to the quest for ultradense and versatile photonic integrations. However, the insufficient optical feedback and mode selection strategies result in a high lasing threshold and multi‐mode operation with limited spectral purity and stability. Here, a multiwavelength near‐infrared plasmonic nanolaser with high mode purity by leveraging a nontrivial “H”‐shape plasmonic cavity is demonstrated. The nanolaser is constructed by inserting InGaAs/GaAs multi‐quantum‐disk (MQD) nanowires into a metallic Fabry‐Perot cavity consisting of a pair of Ag nanowires positioned on an ultrasmooth Au film. The design is endowed with strong optical feedback to enhance the energy transfer between the exciton and plasmon, rendering a significant reduction of the lasing threshold. More importantly, the “H”‐shape cavity is featured with a large flexibility in tuning the resonance wavelength, where multiwavelength lasing with the virtues of single‐mode is realized at room temperature. The results make a crucial step toward near‐infrared multiwavelength plasmonic nanolasers and open up exciting opportunities for applications such as ultracompact photonic integrated circuits and high‐throughput biochemical sensing.

Giant Photoluminescence Enhancement of Monolayer WSe2 Using a Plasmonic Nanocavity with On-Demand Resonance

“…A custom-built confocal darkfield microspectroscopy system was used to measure the scattering spectra of NCoM. 39 In this setup, the p-polarized white light was focused onto the sample using a 50× objective lens (Mitutoyo, NA 0.55) with an incidence angle of 70°. The scattering signal was collected using an upright 50× objective lens (Nikon, NA 0.4).…”