Query: Monolayer semiconductor nanocavity lasers with ultralow thresholds

Candidate papers:

abstract: Engineering the electromagnetic environment of a nanometre scale light emitter by use of a photonic cavity can significantly enhance its spontaneous emission rate, through cavity quantum electrodynamics in the Purcell regime. This effect can greatly reduce the lasing threshold of the emitter, providing a low threshold laser system with small footprint, low power consumption and ultrafast modulation. An ultralow threshold nanoscale laser has been successfully developed by embedding quantum dots into a photonic crystal cavity (PCC) However, several challenges impede the practical application of this architecture, including the random positions and compositional fluctuations of the dots, extreme difficulty in current injection, and lack of compatibility with electronic circuits. Here we report a new lasing strategy: an atomically thin crystalline semiconductor that is, a tungsten diselenide monolayer is non destructively and deterministically introduced as a gain medium at the surface of a pre fabricated PCC. A continuous wave nanolaser operating in the visible regime is thereby achieved with an optical pumping threshold as low as 27 nanowatts at 130 kelvin, similar to the value achieved in quantum dot PCC lasers. The key to the lasing action lies in the monolayer nature of the gain medium, which confines direct gap excitons to within one nanometre of the PCC surface. The surface gain geometry gives unprecedented accessibility and hence the ability to tailor gain properties via external controls such as electrostatic gating and current injection, enabling electrically pumped operation. Our scheme is scalable and compatible with integrated photonics for on chip optical communication technologies.
author_names: Sanfeng Wu

Sonia M Buckley

John R Schaibley

Liefeng Feng

Jiaqiang Yan

David G Mandrus

Fariba Hatami

Wang Yao

Jelena Vuckovic

Arka Majumdar

Xiaodong Xu
title: Monolayer semiconductor nanocavity lasers with ultralow thresholds
venue: Nature
year: 2015

abstract: Engineering the electromagnetic environment of a nanoscale light emitter by a photonic cavity can significantly enhance its spontaneous emission rate through cavity quantum electrodynamics in the Purcell regime. This effect can greatly reduce the lasing threshold of the emitter, providing the ultimate low threshold laser system with small footprint, low power consumption and ultrafast modulation. A state of the art ultra low threshold nanolaser has been successfully developed though embedding quantum dots into photonic crystal cavity (PhCC) However, several core challenges impede the practical applications of this architecture, including the random positions and compositional fluctuations of the dots, extreme difficulty in current injection, and lack of compatibility with electronic circuits. Here, we report a new strategy to lase, where atomically thin crystalline semiconductor, i.e. a tungsten diselenide (WSe2) monolayer, is nondestructively and deterministically introduced as a gain medium at the surface of a pre fabricated PhCC. A new type of continuous wave nanolaser operating in the visible regime is achieved with an optical pumping threshold as low as 27 nW at 130 K, similar to the value achieved in quantum dot PhCC lasers. The key to the lasing action lies in the monolayer nature of the gain medium, which confines direct gap excitons to within 1 nm of the PhCC surface. The surface gain geometry allows unprecedented accessibilities to multi functionalize the gain, enabling electrically pumped operation. Our scheme is scalable and compatible with integrated photonics for on chip optical communication technologies.
author_names: Sanfeng Wu

Sonia M Buckley

John R Schaibley

Liefeng Feng

Jiaqiang Yan

David G Mandrus

Fariba Hatami

Wang Yao

Jelena Vuckovic

Arka Majumdar

Xiaodong Xu
title: Ultra Low Threshold Monolayer Semiconductor Nanocavity Lasers
year: 2015

abstract: Two dimensional (2D) semiconductors are opening a new platform for revitalizing widely spread optoelectronic applications. The realisation of room temperature vertical 2D lasing from monolayer semiconductors is fundamentally interesting and highly desired for appealing on chip laser applications such as optical interconnects and supercomputing. Here, we present room temperature low threshold lasing from 2D semiconductor activated vertical cavity surface emitting lasers (VCSELs) under continuous wave pumping. 2D lasing is achieved from a 2D semiconductor. Structurally, dielectric oxides were used to construct the half wavelength thick cavity and distributed Bragg reflectors, in favour of single mode operation and ultralow optical loss; in the cavity centre, the direct bandgap monolayer WS2 was embedded as the gain medium, compatible with the planar VCSEL configuration and the monolithic integration technology. This work demonstrates 2D semiconductor activated VCSELs with desirable emission characteristics, which represents a major step towards practical optoelectronic applications of 2D semiconductor lasers.Two dimensional materials have recently emerged as interesting materials for optoelectronic applications. Here, Shang et al. demonstrate two dimensional semiconductor activated vertical cavity surface emitting lasers where both the gain material and the lasing characteristics are two dimensional.
author_names: Jingzhi Shang

Chunxiao Cong

Zilong Wang

Namphung Peimyoo

LiShu Wu

Chenji Zou

Yu Zong Chen

Xin Yu Chin

Jianpu Wang

C Soci

Wei Huang

Ting Yu
title: Room temperature 2D semiconductor activated vertical cavity surface emitting lasers
venue: Nature Communications
year: 2017

abstract: Nanoscrolls are a class of nanostructures where atomic layers of 2D materials are stacked consecutively in a coaxial manner to form a 1D spiral topography. Self assembly of chemical vapor deposition grown 2D WS2 monolayer into quasi 1D van der Waals scroll structure instigates a plethora of unique physiochemical properties significantly different from its 2D counterparts. The physical properties of such nanoscrolls can be greatly manipulated upon hybridizing them with high quantum yield colloidal quantum dots, forming 0D/2D structures. The efficient dissociation of excitons at the heterojunctions of QD/2D hybridized nanoscrolls exhibits a 3000 fold increased photosensitivity compared to the pristine 2D material based nanoscroll. The synergistic effects of confined geometry and efficient QD scatterers produce a nanocavity with multiple feedback loops, resulting in coherent lasing action with an unprecedentedly low lasing threshold. Predominant localization of the excitons along the circumference of this helical scroll results in a 12 fold brighter emission for the parallel polarized transition compared to the perpendicular one, as confirmed by finite difference time domain simulation. The versatility of hybridized nanoscrolls and their unique properties opens up a powerful route for not yet realized devices toward practical applications.
author_names: Rapti Ghosh

Hung-I Lin

Yu-Siang Chen

Mukesh Singh

Zhi-Long Yen

Sheng-Kuei Chiu

Hsia-Yu Lin

Krishna Prasad Bera

Yu-Ming Liao

Mario Hofmann

Y P Hsieh

Yang-Fang Chen
title: QD/2D Hybrid Nanoscrolls: A New Class of Materials for High Performance Polarized Photodetection and Ultralow Threshold Laser Action.
venue: Small
year: 2020

abstract: Confining photons in a small space is a difficult task. Recent nanotechnology advances now enable their confinement in a cubic wavelength volume for as long as 1 nanosecond in semiconductors when using 2D photonic crystal (PhC) structures. As shown in Figure 1, a PhC is a periodic optical structure whose periodicity is on the order of the wavelength of light. PhCs are designed to affect the motion of photons1 because they have the optical equivalent of the energy gap of conventional semiconductors. The possibility to manipulate photons in solid materials offers many attractive applications such as nanocavity lasers, tunable slow light devices, and optical integrated circuits. The PhC nanocavity laser is considered one of the best candidates to achieve ultra low threshold lasing due to its small mode volume and high quality factor (Q, which expresses the ability of an oscillating system to keep oscillating before running out of energy) The first reported PhC laser (1999) used multiple quantumwells (QWs) as the gain material at low temperature in pulsed operation.2 Recently, continuous wave (CW) laser operation at low temperature was also reported. However, CW lasing is inherently difficult to achieve at room temperature due to fast non radiative losses that translate into very high Q nanocavity requirements. Our group was the first to demonstrate room temperature operation of a high Q PhC nanocavity CW laser.3 Further improvement of the cavity Q reduced the optical pumping threshold down to the microwatt level.4 3D photon confinement can be achieved by fabricating the PhC slab structure with a nanocavity (see Figure 1) The 2D triangular lattice confines photons in the plane of the slab. The excitation beam generates excitons in quantum dots (QDs) embedded into the slab layer and the excitons recombine with photon emission. Our PhC nanocavity was designed to have its resonant wavelength at the excitonic photoluminescence (PL) peak, allowing CW lasing at 1.33mm at room temperature with Figure 1. Scanning electron micrographs of a photonic crystal nanocavity structure. Top (a) and cross sectional (b) views. QD: quantum dot.
author_names: Masahiro Nomura
title: A photonic crystal nanocavity laser with ultralow threshold
year: 2007

abstract: A room temperature polariton nanolaser is demonstrated using quantum heterostructure nanocavities to boost exciton properties. Ultralow threshold coherent light emitters can be achieved through lasing from exciton polariton condensates, but this generally requires sophisticated device structures and cryogenic temperatures. Polaritonic nanolasers operating at room temperature lie on the crucial path of related research, not only for the exploration of polariton physics at the nanoscale but also for potential applications in quantum information systems, all optical logic gates, and ultralow threshold lasers. However, at present, progress toward room temperature polariton nanolasers has been limited by the thermal instability of excitons and the inherently low quality factors of nanocavities. Here, we demonstrate room temperature polaritonic nanolasers by designing wide gap semiconductor heterostructure nanocavities to produce thermally stable excitons coupled with nanocavity photons. The resulting mixed states of exciton polaritons with Rabi frequencies of approximately 370 meV enable persistent polariton lasing up to room temperature, facilitating the realization of miniaturized and integrated polariton systems.
author_names: Jang-Won Kang

Bokyung Song

Wenjing Liu

Seong-Ju Park

Ritesh Agarwal

Chang-Hee Cho
title: Room temperature polariton lasing in quantum heterostructure nanocavities
venue: Science Advances
year: 2019

abstract: Reliable technologies for the monolithic integration of lasers onto silicon represent the holy grail for chip level optical interconnects. In this context, nanowires (NWs) fabricated using III V semiconductors are of strong interest since they can be grown site selectively on silicon using conventional epitaxial approaches. Their unique one dimensional structure and high refractive index naturally facilitate low loss optical waveguiding and optical recirculation in the active NW core region. However, lasing from NWs on silicon has not been achieved to date, due to the poor modal reflectivity at the NW silicon interface. We demonstrate how, by inserting a tailored dielectric interlayer at the NW Si interface, low threshold single mode lasing can be achieved in vertical cavity GaAs AlGaAs core shell NW lasers on silicon as measured at low temperature. By exploring the output characteristics along a detection direction parallel to the NW axis, we measure very high spontaneous emission factors comparable to nanocavity lasers (b 0.2) and achieve ultralow threshold pump energies =11 pJ/pulse. Analysis of the input output characteristics of the NW lasers and the power dependence of the lasing emission line width demonstrate the potential for high pulsation rates =250 GHz. Such highly efficient nanolasers grown monolithically on silicon are highly promising for the realization of chip level optical interconnects.
author_names: Benedikt F Mayer

Lisa Janker

Bernhard Loitsch

Julian Treu

T Kostenbader

Stefan Lichtmannecker

Thorsten Reichert

Stefanie Morkotter

Michael Kaniber

Gerhard Abstreiter

Cheryl Gies

Gregor Koblmuller

Jonathan J Finley
title: Monolithically Integrated High b Nanowire Lasers on Silicon.
venue: Nano letters
year: 2016

abstract: Recently, rolled up semiconductor tubes, formed when a coherently strained semiconductor bilayer is selectively released from the host substrate, have emerged as a promising technique to realize high performance optical micro and nanocavity devices [1 6] Combining the advantages of both top down and bottom up fabrication processes, this approach offers an exceptional flexibility for achieving semiconductor micro and nanotube structures with an epitaxially smooth surface and well controlled diameters and wall thicknesses using a single photolithography step. However, lasing in such tube structures has hitherto not been demonstrated. In this context, we have performed a detailed investigation of the fabrication and characterization of rolled up micro and nanotubes, with the incorporation of self organized InGaAs/GaAs quantum dots as the gain media. We have achieved, for the first time, lasing in rolled up semiconductor tubes at room temperature. The devices are characterized an ultralow threshold power 4 mW) an intrinsic lasing linewidth of 0.2 0.3 nm, and a linear polarization with the electric field parallel to the tube surface.
author_names: Zetian Mi

F Li
title: Rolled up InGaAs/GaAs quantum dot micro and nanotube lasers
venue: 2010 IEEE Photonics Society Winter Topicals Meeting Series (WTM)
year: 2010

abstract: ZnO microspheres fabricated via laser ablation in superfluid helium were found to have bubble like voids. Even a microsphere demonstrating clear whispering gallery mode resonances in the luminescence had voids. Our analysis confirmed that the voids are located away from the surface and have negligible or little effect on the whispering gallery mode resonances since the electromagnetic energy localizes near the surface of these microspheres. The existence of the voids indicates that helium gas or any evaporated target material was present within the molten microparticles during the microsphere formation. (c) 2018 Optical Society of America OCIS codes: (220.4000) Microstructure fabrication; (140.3945) Microcavities. References and links 1. J. R. Buck and H. J. Kimble, "Optimal sizes of dielectric microspheres for cavity QED with strong coupling," Physical Review A 67, 033806 (2003) 2. S. M. Spillane, T. J. Kippenberg, and K. J. Vahala, "Ultralow threshold Raman laser using a spherical dielectric microcavity," Nature 415, 621 623 (2002) 3. F. Treussart, V. S. Ilchenko, J. F. Roch, J. Hare, V. Lefevre Seguin, J. M. Raimond, and S. Haroche, "Evidence for intrinsic Kerr bistability of high Q microsphere resonators in superfluid helium," The European Physical Journal D Atomic, Molecular, Optical and Plasma Physics 1, 235 238 (1998) 4. G. W. 't Hooft, W. A. J. A. van der Poel, L. W. Molenkamp, and C. T. Foxon, "Giant oscillator strength of free excitons in GaAs," Physical Review B 35, 8281 8284 (1987) 5. M. Nagai, F. Hoshino, S. Yamamoto, R. Shimano, and M. Kuwata Gonokami, "Spherical cavity mode laser with self organized CuCl microspheres," Optics Letters 22, 1630 1632 (1997) 6. T. H. B. Ngo, C. H. Chien, S. H. Wu, and Y. C. Chang, "Size and morphology dependent evolution of resonant modes in ZnO microspheres grown by hydrothermal synthesis," Optics Express 24, 16010 16015 (2016) 7. W. Stober, A. Fink, and E. Bohn, "Controlled growth of monodisperse silica spheres in the micron size range," Journal of Colloid and Interface Science 26, 62 69 (1968) 8. M. L. Gorodetsky, A. A. Savchenkov, and V. S. Ilchenko, "Ultimate Q of optical microsphere resonators," Optics Letters 21, 453 455 (1996) 9. N. G. Semaltianos, "Nanoparticles by Laser Ablation," Critical Reviews in Solid State and Materials Sciences 35, 105 124 (2010) 10. S. Okamoto, S. Ichikawa, Y. Minowa, and M. Ashida, "Optical Fabrication of Semiconductor Single Crystalline Microspheres in Superfluid Helium," MRS Online Proceedings Library Archive 1635, 103 108 (2014) 11. S. Okamoto, K. Inaba, T. Iida, H. Ishihara, S. Ichikawa, andM. Ashida, "Fabrication of single crystalline microspheres with high sphericity from anisotropic materials," Scientific Reports 4, 5186 (2014) 12. S. Okamoto, Y. Minowa, and M. Ashida, "White light lasing in ZnO microspheres fabricated by laser ablation," in "SPIE OPTO," (International Society for Optics and Photonics, 2012) pp. 82630K 82630K. 13. E. B. Gordon, A. V. Karabulin, V. I. Matyushenko, V. D. Sizov, and I. I. Khodos, "Stability of micron sized spheres formed by pulsed laser ablation of metals in superfluid helium and water," High Energy Chemistry 48, 206 212 (2014) 14. K. Inaba, K. Imaizumi, K. Katayama, M. Ichimiya, M. Ashida, T. Iida, H. Ishihara, and T. Itoh, "Optical manipulation of CuCl nanoparticles under an excitonic resonance condition in superfluid helium," physica status solidi (b) 243, 3829 3833 (2006) 15. D. Nakamura, T. Smogaki, K. Okazaki, M. Higashihata, H. Ikenoue, and T. Okada, "Synthesis of Various Sized ZnO Microspheres by Laser Ablation and Their Lasing Characteristics," Journal of Laser Micro/Nanoengineering 8, 296 299 (2013) 16. U. Ozgur, Y. I. Alivov, C. Liu, A. Teke, M. Reshchikov, S. Dogan, V. Avrutin, S. J. Cho, and H. Morkoc, "A comprehensive review of ZnO materials and devices," Journal of applied physics 98, 11 (2005) 17. C. F. Bohren and D. R. Huffman, Absorption and scattering of light by small particles (Wiley, 1983) 18. T. Nobis and M. Grundmann, "Low order optical whispering gallery modes in hexagonal nanocavities," Physical Review A 72, 063806 (2005) ar X iv :1 70 3. 01 17 8v 1 co nd m at .m tr lsc i] 1 M ar 2 01 7 19. V. V. Datsyuk, "Some characteristics of resonant electromagnetic modes in a dielectric sphere," Applied Physics B 54, 184 187 (1992) 20. A. N. Oraevsky, "Whispering gallery waves," Quantum Electronics 32, 377 (2002) 21. V. V. Datsyuk and I. A. Izmailov, "Optics of microdroplets," Physics Uspekhi 44, 1061 (2001) 22. H. Miura, E. Yokoyama, K. Nagashima, K. Tsukamoto, and A. Srivastava, "A new constraint for chondrule formation: condition for the rim formation of barred olivine textures," Earth, Planets and Space 63, 8 (2011) 23. T. Ihara, H. Wagata, T. Kogure, K. Katsumata, K. Okada, and N. Matsushita, "Template free solvothermal preparation of ZnO hollow microspheres covered with c planes," RSC Advances 4, 25148 25154 (2014) 24. K. T. Gahagan and G. A. Swartzlander, "Optical vortex trapping of particles," Optics Letters 21, 827 829 (1996)
title: Inner structure of ZnO microspheres fabricated via laser ablation in superfluid helium
year: 2018

abstract: Summary form only given. Miniaturization of semiconductor lasers holds the key to the development of compact, low threshold, and fast coherent on chip light sources/amplifiers, which are critically important for emerging applications in nanophotonics, integrated optics, and information technology. However, on chip integration of nanoscale electronic components with conventional semiconductor lasers utilizing dielectric optical cavities is impeded by the diffraction limit i.e. (l/2n)3 for three dimensional (3D) cavities, where l is the free space wavelength and n is the refractive index of the dielectric. The recent advent of nanoplasmonics based on metallodielectric structures has led to the design of optical components and optoelectronic devices in the deep subwavelength regime. In particular, a new class of lasers based on surface plasmon amplification by stimulated emission of radiation (SPASER) has recently been proposed and experimentally demonstrated (16 19) In the SPASER operation, surface plasmons excited in noble metal structures adjacent to gain media dramatically increase the optical mode density, shrink the optical mode volume, and provide the necessary feedback mechanism. Among the available plasmonic cavity materials in the visible and near infrared ranges, silver (Ag) is the best choice due to minimal plasmonic damping. However, so far, most plasmonic devices are based on granular polycrystalline Ag films where strong surface roughness and grain boundaries lead to strong scattering losses of surface plasmon polaritons (SPPs) Thus, atomically smooth or single crystalline plasmonic structures are desirable building blocks for low loss applications. In polycrystalline metallic materials the lasing threshold of plasmonic nanolasers remains impractically high and the continuous wave (CW) operation of a plasmonic laser has yet to be demonstrated. Having developed epitaxially grown, atomically smooth Ag films as a new plasmonic platform, we report a SPASER under CW operation with an ultralow lasing threshold at liquid nitrogen temperature and mode volume well below the 3D diffraction limit. The device is based on the plasmonic nanocavity formed between epitaxial Ag film and a single nanorod consisting of a gallium nitride (GaN) shell and an indium gallium nitride (InGaN) core acting as gain medium. The nanolaser emits in the green spectral region with perfectly polarized far field radiation at the main lasing mode. In comparison with other semiconductor gain media, the large gain coefficient of InGaN plays a critical role in the ultralow lasing threshold observed for our experiment with a 3D subdiffraction cavity. The development of atomically smooth epitaxial Ag on Si as a new platform for plasmonics not only allows us to demonstrate the SPASER enabled nanolaser, it should also promote the development of monolithically integrated plasmonics and Si based electronics on a single platform.
author_names: Yu-Jung Lu

Jisun Kim

Hung-Ying Chen

Chihhui Wu

Charlotta E Sanders

Chun-Yuan Wang

Wen-Hao Chang

Gennady Shvets

Shangjr Gwo

Chih-Kang Shih
title: Nanolasers employing epitaxial plasmonic layers
venue: CLEO: 2013
year: 2013