Electrically Driven Plasmonic Lasing with Record-low Threshold

Electrically driven nanolasers have attracted considerable attention owing to their potential in miniaturize coherent light sources beyond the diffraction limit, enabling ultra-compact photonic integrated circuits. Although significant progress has been made in this field, electrically driven lasing with an ultralow threshold remains challenging. Here, we demonstrate an electrically driven laser by two AA batteries with a threshold of 58 mA cm⁻², which is three-order-of-magnitude lower than the previous record. This breakthrough is mainly attributed to the Bloch surface plasmon polariton (Bloch-SPP) nanocavity, which provides orders of magnitude enhancement electromagnetic field, leading to significantly improved interaction between the gain medium and the optical cavity. Simultaneously, the nanocavity maintains an ultrahigh quality (Q) factor and balanced transparency. Feedbacked by this plasmonic nanocavity, directional lasing with a narrow linewidth, linear polarization, and spatial coherence is achieved. In addition, the laser exhibits excellent operational stability over 24 h (T₅₀ = 24.1 h). These verified lasing properties demonstrate that our device outperforms previously reported electrically driven organic lasers and dual-cavity perovskite lasers. Owing to the advances of the plasmonic cavity, electrically driven lasers that gained by various media is possible. Consequently, applications based on on-chip coherent light sources can be explored and developed.