Plasmonic nanolasers have received a substantial interest for their promising applications in integrated photonics, optical sensing, and biomedical imaging. To date, a room-temperature plasmonic nanolaser, submicron in all dimensions, remains elusive in the visible regime due to high metallic losses. Here, we demonstrate single-particle lasing around 2.3 eV with full-submicron, cesium lead bromide perovskite (CsPbBr3) crystals atop polymer-coated gold substrates at room temperature. With a large number (~100) of devices in total, we systematically study the lasing action of plasmonic test and photonic control groups. The achieved smallest plasmonic laser was 0.56 micrometer x 0.58 micrometer x 0.32 micrometer in size, ten-fold smaller than that of our smallest photonic laser. Key elements to efficient plasmonic lasing are identified as enhanced optical gain by the Purcell effect, long carrier diffusivity, a large spontaneous emission factor, and a high group index. Our results shed light on three-dimensional miniaturization of plasmonic lasers.
Recently there is an increasing attention to electrically pumped room temperature sub-wavelength plasmon sources because of their various potential applications mainly in the integrated plasmonic field. In this paper, a GaAs/AlGaAs quantum dot based waveguide integrated plasmonic nanolaser is introduced and theoretically investigated. Using a semi-classical rate equation model, performance of our nanolaser is studied and its characteristics are presented in details. The proposed nanolaser has a tiny footprint of 0.25 um2, room temperature operating condition and CMOS friendly process while hav…
In this work, we present a fully quantum theory of the plasmonic nanolaser, based on the maser model. Theory can be applied both to the microlasers with high Q-factor cavities and plasmonic nanolasers. We show that the latter is essentially a thresholdless device. We obtain the statistics of quanta, spectrum of the plasmonic radiation and the second-order coherence degree in the steady state. The limits of the model applicability are discussed in detail. All results are compared with the full numerical simulation.
We propose and demonstrate a hybrid photonic-plasmonic nanolaser that combines the light harvesting features of a dielectric photonic crystal cavity with the extraordinary confining properties of an optical nano-antenna. In that purpose, we developed a novel fabrication method based on multi-step electron-beam lithography. We show that it enables the robust and reproducible production of hybrid structures, using fully top down approach to accurately position the antenna. Coherent coupling of the photonic and plasmonic modes is highlighted and opens up a broad range of new hybrid nanophotonic d…
Plasmonic waveguides are an essential element of nanoscale coherent sources, including nanolasers and four-wave mixing (FWM) devices. Here we report how the design of the plasmonic waveguide needs to be guided by the ultimate application. This contrasts with traditional approaches in which the waveguide is considered in isolation. We find that hybrid plasmonic waveguides, with a nonlinear material sandwiched between the metal substrate and a high-index layer, are best suited for FWM applications, whereas metallic wedges are preferred in nanolasers. We also find that in plasmonic nanolasers hig…
We report an approach of realization and characterization of a novel plasmonic-photonic hybrid nanodevice. The device comprises a plasmonic nano-antenna (NA) and a defect mode based PC cavity, and were fabricated based on a multi-step electron-beam lithography. The laser emission of the devices was demonstrated and the coupling conditions between the NA and PC cavity were investigated in near-field level.
We consider plasmonic nanoantennas immersed in active host medium. Specifically shaped metal nanoantennas can exhibit strong magnetic properties in the optical spectral range due to the excitation of Magnetic Plasmon Resonance (MPR). A case when a metamaterial comprising such nanoantennas can demonstrate both "left-handiness" and negative permeability in the optical range is considered. We show that high losses predicted for optical "left- handed" materials can be compensated in the gain medium. Gains required to achieve local generation in such magnetic active metamaterials are calculated for…
There are many researches reported in using Germanium in Silicon based lasers but acquiring this potential for a nanolaser may also be important for development of a CMOS compatible plasmon source. In this paper, a Ge/SiGe multiple quantum well waveguide integrated nanolaser is introduced and theoretically investigated. This structure is simulated and by means of a semi-classical rate equation model, its performance is studied. The proposed nano laser has a tiny footprint of 0.07um^2, room temperature performance and CMOS compatible fabrication process. The output performance of the proposed s…
We present a plasmonic waveguide where light pulses are stopped at well-accessed complex-frequency zero-group-velocity points. Introducing gain at such points results in cavity-free, "thresholdless" nanolasers beating the diffraction limit via a novel, stopped-light mode-locking mechanism.
Plasmonic devices have advanced significantly in the past decade. Being one of the most intriguing devices, plamonic nanolasers plays an important role in biomedicine, chemical sensor, information technology, and optical integrated circuits. However, nanoscale plasmonic devices, particularly in ultraviolet regime, are extremely sensitive to metal and interface quality, which renders the development of ultraviolet plasmonics. Here, by addressing the material issues, we demonstrate a low threshold, high characteristic temperature metal-oxide-semiconductor ZnO nanolaser working at room temperatur…
Spasers have been theoretically predicted and experimentally observed and promise to deliver new exciting nanophotonic and biomedical applications. Here we theoretically investigate ultrafast dynamical properties of spasers with external plasmonic feedback. We consider a spaser both as a nanoscale source and detector of plasmons which could be used to design novel nano-imaging and sensing techniques. We show that, as with conventional lasers, spasers are sensitive to external feedback. However, unlike the lasers, spasers have faster relaxation dynamics which could be used to develop new ultras…
Nanolasers have great potential as both on-chip light sources and optical barcoding particles. We demonstrate ultrasmall InGaP and InGaAsP disk lasers with diameters down to 360 nm (198 nm in height) in the red spectral range. Optically pumped, room-temperature, single-mode lasing was achieved from both disk-on-pillar and isolated particles. When isolated disks were placed on gold, plasmon polariton lasing was obtained with Purcell-enhanced stimulated emission. UV lithography and plasma ashing enabled the fabrication of nanodisks on a wafer-scale, with intended random size variation. Silica-co…
Plasmonic nanolasers have ultrahigh lasing thresholds, especially those devices for which all three dimensions are truly subwavelength. Because of a momentum mismatch between the propagating light and localized optical field of the subwavelength nanocavity, poor optical pumping efficiency is another important reason for the ultrahigh threshold but is normally always ignored. Based on a cavity-embedded nanoantenna array design, we demonstrate a room-temperature low-threshold plasmonic nanolaser that is robust, reproducible, and easy-to-fabricate using chemical-template lithography. The mode vol…
We demonstrate theoretically that a subwavelength spherical dielectric nanoparticle coated with a gain shell forms a nanolaser. Lasing modes of such a nanolaser are associated with the Mie resonances of the nanoparticle. We establish a general condition for the lasing threshold and show that the use of high refractive index dielectric media allows for lasing with a threshold significantly lower than that for nanolasers incorporating lossy plasmonic metals.
Solution-processed lead halide perovskites have shown very bright future in both solar cells and microlasers. Very recently, the nonlinearity of perovskites started to attract considerable research attention. Second harmonic generation and two-photon absorption have been successfully demonstrated. However, the nonlinearity based perovskite devices such as micro- & nano- lasers are still absent. Here we demonstrate the two-photon pumped nanolasers from perovskite nanowires. The CH3NH3PbBr3 perovskite nanowires were synthesized with one-step solution self-assembly method and dispersed on glass s…
Half-wave plasmonic nanolasers near the localization limit
Harvard Medical School（哈佛医学院）；Massachusetts General Hospital（麻省总医院）；Rice University（莱斯大学）；Harvard-MIT Health Sciences and Technology（哈佛-麻省理工学院健康科学与技术）；Massachusetts Institute of Technology（麻省理工学院）
Selective control of light is essential for optical science and technology with numerous applications. Nanophotonic waveguides and integrated couplers have been developed to achieve selective coupling and spatial control of an optical beam according to its multiple degrees of freedom. However, previous coupling devices remain passive with an inherently linear response to the power of incident light limiting their maximal optical selectivity. Here, we demonstrate nonlinear optical selectivity through selective excitation of individual single-mode nanolasers based on the spin and orbital angular…
Whether dispersal of plasmonic nanoparticles (NPs) within a perovskite active layer can increase the efficiency of solar cells is a long-standing question. It is well known that inclusion of metallic NPs in an active layer can boost the surrounding near-field intensity around them owing to the dipolar localized surface plasmon resonance (LSPR, also called antenna effect), which can increase light absorption by solar cells. However, the use of plasmonic NPs in perovskite solar cells has been barely reported, and it is not known whether inserting plasmonic NPs into a perovskite active layer prod…
All-dielectric subwavelength structures utilizing Mie resonances provide a novel paradigm in nanophotonics for controlling and manipulating light. So far, only spontaneous emission enhancement was demonstrated with single dielectric nanoantennas, whereas stimulated emission was achieved only in large lattices supporting collective modes. Here, we demonstrate the first single-particle all-dielectric monolithic nanolaser driven by Mie resonances in visible and near-IR frequency range. We employ halide perovskite CsPbBr$_3$ as both gain and resonator material that provides high optical gain (up t…
We provide a numerical study showing that a bottom reflector is indispensable to achieve unidirectional emission from a photonic-crystal (PhC) nanolaser. First, we study a PhC slab nanocavity suspended over a flat mirror formed by a dielectric or metal substrate. We find that the laser's vertical emission can be enhanced by more than a factor of six compared with the device in the absence of the mirror. Then, we study the situation where the PhC nanocavity is in contact with a flat metal surface. The underlying metal substrate may serve as both an electrical current pathway and a heat sink, wh…
Next-generation optoelectronic devices and photonic circuitry will have to incorporate on-chip compatible nanolaser sources. Semiconductor nanowire lasers have emerged as strong candidates for integrated systems with applications ranging from ultrasensitive sensing, to data communication technologies. Despite significant advances in their fundamental aspects, the integration within scalable photonic circuitry remains challenging. Here we report on the realization of hybrid photonic devices consisting of nanowire lasers integrated with wafer-scale lithographically designed V-groove plasmonic wa…
Nanoscale light sources are being intensively investigated for their potential to enable low-energy, high-density optical communication and sensing systems. Both nano-light-emitting diodes (nanoLEDs) and nanolasers have been considered, based on advanced nanophotonic concepts such as photonic crystals and plasmonic structures, with dimensions well into the sub-micrometer domain. With decreasing dimensions, light-matter interaction becomes stronger, potentially leading to efficient and ultrafast radiative emission, both in the spontaneous and stimulated regime. These features have created wide …
The last two decades have witnessed tremendous advancements in the area of nanophotonics and plasmonics. Undoubtedly, the introduction of metallic structures has opened a path towards light confinement and manipulation at the subwavelength scale { a regime that was previously thought to be out of reach in optics. Of central importance is to devise efficient light sources to power up the future nanoscale optical circuits. Coaxial resonators can provide a platform to implement such subwavelength sources. They support ultrasmall cavity modes and offer large mode-emitter overlap as well as multifo…
We considered the set of the ordered split-ring silver resonators in the form of nanosize horseshoes arranged in a layer at the surface of the active dielectric medium. The size of the horseshoe resonator is much less than the wavelength of the incident light. The plasmon nanoresonator takes energy from the active medium and can operate as a nanolaser. We show that nanoscale laser pumping should be treated as a random external force because of the incoherent quantum-mechanical process of photon absorption in the active medium. The operation of the plasmonic nanoresonator immersed in the active…
The nanoscale mode volumes of surface plasmon polaritons have enabled plasmonic lasers and condensates with ultrafast operation. Most plasmonic lasers are based on noble metals, rendering the optical mode structure inert to external fields. Here, we demonstrate active magnetic-field control over lasing in a periodic array of Co/Pt multilayer nanodots immersed in an IR-140 dye solution. We exploit the magnetic nature of the nanoparticles combined with mode tailoring to control the lasing action. Under circularly polarized excitation, angle-resolved photoluminescence measurements reveal a transi…
Synthetic perovskites with photovoltaic properties open a new era in solar photovoltaics. Due to high optical absorption perovskite-based thin-film solar cells are usually considered as fully absorbing solar radiation on condition of ideal blooming. However, is it really so? The analysis of the literature data has shown that the absorbance of all photovoltaic pervoskites has the spectral hole at infrared frequencies where the solar radiation spectrum has a small local peak. This absorption dip results in the decrease of the optical efficiency of thin-film pervoskite solar cells by nearly 3% an…
Lasers are ubiquitous for information storage, processing, communications, sensing, biological research, and medical applications [1]. To decrease their energy and materials usage, a key quest is to miniaturize lasers down to nanocavities [2]. Obtaining the smallest mode volumes demands plasmonic nanocavities, but for these, gain comes from only single or few emitters. Until now, lasing in such devices was unobtainable due to low gain and high cavity losses [3]. Here, we demonstrate a plasmonic nanolaser approaching the single-molecule emitter regime. The lasing transition significantly broade…
Nanophotonic objects like plasmonic nanoparticles and colloidal quantum dots can complement the functionality of molecular dyes in biomedical optics. However, their operation is usually governed by spontaneous processes, which results in broad spectral features and limited signal-to-noise ratio, thus restricting opportunities for spectral multiplexing and sensing. Lasers provide the ultimate spectral definition and background suppression, and their integration with cells has recently been demonstrated. However, laser size and threshold remain problematic. Here, we report on the design, high-th…
Photoluminescence is a phenomenon of significant interest due to its wide range of technological applications in plasmonics, nanolasers, spasers, lasing spasers, loss compensation and gain in metamaterials, and luminescent media. Nanostructured materials are known to have very different luminescence characteristics to bulk samples or planar films. Here we show that by engineering a nanostructured meta-surface, we can choose the position of photoluminescence absorption and emission lines of thin gold films. The nanostructuring also aids to strong enhancement of the emission from gold, by a fact…
By using the real-space method, switching of a single plasmon interacting with a hybrid nanosystem composed of a semiconductor quantum dot (SQD) and a metallic nanoparticle (MNP) coupled to one-dimensional surface plasmonic waveguide is investigated theoretically. We discussed that the dipole coupling between an exciton and a localized surface plasmon results in the formation of a hybrid exciton and the transmission and reflection of the propagating single plasmon could be controlled by changing the interparticle distance between the SQD and the MNP and the size of the nanoparticles. The contr…
Metallic-Cavity lasers or plasmonic nanolasers of sub-wavelength sizes have attracted great attentions in recent years, with the ultimate goal of achieving continuous wave (CW), room temperature (RT) operation under electrical injection. Despite great efforts, a conclusive and convincing demonstration of this goal has proven challenging. By overcoming several fabrication challenges imposed by the stringent requirement of such small scale devices, we were finally able to achieve this ultimate goal. Our metallic nanolaser with a cavity volume of 0.67λ3 (λ=1591 nm) shows a linewidth of 0.5 nm at …
Design and Analysis of Plasmonic-Nanorod-Enhanced Lead-Free Inorganic Perovskite/Silicon Heterojunction Tandem Solar Cell Exceeding the Shockley-Queisser Limit
Coherent nanoscale photon sources are of paramount importance to achieving all-optical communication. Several nanolasers smaller than the diffraction limit have been theoretically proposed and experimentally demonstrated using plasmonic cavities to confine optical fields. Such compact cavities exhibit large Purcell factors, thereby enhancing spontaneous emission, which feeds into the lasing mode. However, most plasmonic nanolasers reported so far have employed resonant nanostructures and therefore had the lasing restricted to the proximity of the resonance wavelength. Here, we report on an app…
In this work, we study the lasing conditions of the transverse electric (TE) modes of micro- and nanotubes coated internally with a thin metallic layer. This geometry may tackle some of the problems of nanolasers and spasers as it allows the recycling of the active medium while providing a tunable plasmonic cavity. The system presents two types of TE modes: cavity modes (CMs) and whispering-gallery modes (WGMs). On the one hand, we show that the lasing of WGM is only possible in nanoscale tubes. On the other hand, for tubes of some micrometers of diameter, we found that the system presents a l…
Nanoantennas offer the ultimate spatial control over light by concentrating optical energy well below the diffraction limit, whereas their quality factor (Q) is constrained by large radiative and dissipative losses. Dielectric microcavities, on the other hand, are capable of generating a high Q-factor through an extended photon storage time but have a diffraction-limited optical mode volume. Here we bridge the two worlds, by studying an exemplary hybrid system integrating plasmonic gold nanorods acting as nanoantennas with an on-resonance dielectric photonic crystal (PC) slab acting as a low-l…
A key component for optical on-chip communication is an efficient light source. However, to enable low energy per bit communication and local integration with Si CMOS, devices need to be further scaled down. In this work, we fabricate micro- and nanolasers of different shapes in InP by direct wafer bonding on Si. Metal-clad cavities have been proposed as means to scale dimensions beyond the diffraction limit of light by exploiting hybrid photonic-plasmonic modes. Here, we explore the size scalability of whispering-gallery mode light sources by cladding the sidewalls of the device with Au. The …
On-chip light sources are critical for the realization of fully integrated photonic circuitry. So far, semiconductor miniaturized lasers have been mainly limited to sizes on the order of a few microns. Further reduction of sizes is challenging fundamentally due to the associated radiative losses. While using plasmonic metals helps to reduce radiative losses and sizes, they also introduce Ohmic losses hindering real improvements. In this work, we show that, making use of quasi-bound states in the continuum, or supercavity modes, we circumvent these fundamental issues and realize the smallest pu…
Hybrid organic-inorganic perovskites have emerged as very promising materials for photonic applications, thanks to the great synthetic versatility that allows to tune their optical properties. In the two-dimensional (2D) crystalline form, these materials behave as multiple quantum-well heterostructures with stable excitonic resonances up to room temperature. In this work strong light-matter coupling in 2D perovskite single-crystal flakes is observed, and the polarization-dependent exciton-polariton response is used to disclose new excitonic features. For the first time, an out-of-plane compone…
Biexcitons are a manifestation of many-body excitonic interactions crucial for quantum information and quantum computation in the construction of coherent combinations of quantum states. However, due to their small binding energy and low transition efficiency, most biexcitons in conventional semiconductors exist either at cryogenic temperature or under femtosecond pulse laser excitation. Here we demonstrate room temperature, continuous wave driven biexciton states in CsPbBr3 perovskite nanocrystals through coupling with a plasmonic nanogap. The room temperature CsPbBr3 biexciton excitation flu…
