Nanoscale Core–Shell Hyperbolic Structures for Ultralow Threshold Laser Action: An Efficient Platform for the Enhancement of Optical Manipulation

Abstract

Plasmonic material has emerged with multifunctionalities for its remarkable tailoring light emission, reshaping density of states (DOS), and focusing subwavelength light. However, restricted by its propagation loss and narrowband resonance in nature, it is a challenge for plasmonic material to provide a broadband DOS to advance its application. Here, we develop a novel nanoscale core−shell hyperbolic structure that possesses a remarkable coupling effect inside the multishell nanoscale composite owing to a higher DOS and a longer time of collective oscillations of the electrons than the plasmonic-based pure-metal nanoparticles. Subsequently, a giant localized electromagnetic wave of surface plasmon resonance is formed at the surface, causing pronounced out-coupling effect. Specifically, the nanoscale core−shell hyperbolic structure confines the energy well without being decayed, reducing the propagation loss and then achieving an unprecedented stimulated emission (random lasing action by dye molecule) with a record ultralow threshold (∼30 μJ/cm 2 ). Besides, owing to the radial symmetry of the nanoscale core−shell hyperbolic structure, the excitation of high wavevector modes and induced additional DOS are easily accessible. We believe that the nanoscale core−shell hyperbolic structure paves a way to enlarge the development of plasmonic-based applications, such as high optoelectronic conversion efficiency of solar cells, great power extraction of light-emitting diodes, wide spectra photodetectors, carrying the emitter inside the core part as quantitative fluorescence microscopy and bioluminescence imaging system for in vivo and in vitro research on human body.

Self-Sufficient and Highly Efficient Gold Sandwich Upconversion Nanocomposite Lasers for Stretchable and Bio-applications

“…The above-mentioned benefits produce a perfect platform to lower the threshold to trigger a random laser action. Therefore, the trends of scattering efficiency and mode volume match well with our previous report Figure d,e shows the electric-field distributions of the Au 1 –UCNP–Au 2 nanocomposites at the wavelengths of 545 and 658 nm, respectively.…”

“…Therefore, the trends of scattering efficiency and mode volume match well with our previous report. 25 Figure 3d,e shows the electric-field distributions of the Au 1 −UCNP−Au 2 nanocomposites at the wavelengths of 545 and 658 nm, respectively. The energy distributions at the wavelength of 545 nm demonstrate that the energy is strongly confined near the UCNP sandwiched in between gold nanoparticles.…”

“…Random lasers are the lasers where the gain medium itself comprises scattering centers, leading to a feedback loop mechanism for lasing action to occur . When the random laser device is optically excited, the photons are multiply scattered inside the gain medium, which enables coherent closed loops . The resulting random cavities in the gain medium act as resonators for multiple wavelengths, thus giving out multiple peaks in random lasing spectra.…”

“…24 When the random laser device is optically excited, the photons are multiply scattered inside the gain medium, which enables coherent closed loops. 25 The resulting random cavities in the gain medium act as resonators for multiple wavelengths, thus giving out multiple peaks in random lasing spectra. The isotropic nature of the random lasing action makes it suitable for various display applications, bioimaging, 26 solid-state lighting, etc.…”

Plasmonic Nanolasers in On-Chip Light Sources: Prospects and Challenges

“…Three seminal works occurred in 2009 with different configurations inspiring the following works: metal–insulator–semiconductor (MIS) structure, metal–insulator–metal (MIM) waveguide, and core–shell spaser. − In 2012, the plasmonic crystal laser emerged as another important member . Besides, different cavity feedback architectures based on nanodisk–pan, quantum well, nanosquare, coaxial metal cladded structure, quantum dots (QDs) in a nanowire, pseudowedge structure, confined Tamm plasmon , and hyperbolic cavity , were reported. In general, the metal supports the plasmon mode, and the semiconductor provides sufficient gain to compensate for the large Ohmic loss.…”