The effects of cavity quantum electrodynamics (QED), caused by the interaction of matter and the electromagnetic field in subwavelength resonant structures, have been the subject of intense research in recent years1. The generation of coherent radiation by subwavelength resonant structures has attracted considerable interest, not only as a means of exploring the QED effects that emerge at small volume, but also for its potential in applications ranging from on-chip optical communication to ultrahigh-resolution and high-throughput imaging, sensing and spectroscopy. One such strand of research is aimed at developing the ‘ultimate’ nanolaser: a scalable, low-threshold, efficient source of radiation that operates at room temperature and occupies a small volume on a chip2. Different resonators have been proposed for the realization of such a nanolaser—microdisk3 and photonic bandgap4 resonators, and, more recently, metallic5, 6, metallo-dielectric7, 8, 9, 10 and plasmonic11, 12 resonators. But progress towards realizing the ultimate nanolaser has been hindered by the lack of a systematic approach to scaling down the size of the laser cavity without significantly increasing the threshold power required for lasing. Here we describe a family of coaxial nanostructured cavities that potentially solve the resonator scalability challenge by means of their geometry and metal composition. Using these coaxial nanocavities, we demonstrate the smallest room-temperature, continuous-wave telecommunications-frequency laser to date. In addition, by further modifying the design of these coaxial nanocavities, we achieve thresholdless lasing with a broadband gain medium. In addition to enabling laser applications, these nanoscale resonators should provide a powerful platform for the development of other QED devices and metamaterials in which atom–field interactions generate new functionalities13, 14.
At a glance
- 1994) , ed. Cavity Quantum Electrodynamics (Academic,
- Seeking the ultimate nanolaser. Science 314, 260–261 (2006)
- Whispering-gallery mode microdisk lasers. Appl. Phys. Lett. 60, 289–291 (1992) , , , &
- Two-dimensional photonic band-gap defect mode laser. Science 284, 1819–1821 (1999) et al.
- Lasing in metallic-coated nano-cavities. Nature Photon. 1, 589–594 (2007) et al.
- Microcavity laser oscillating in a circuit-based resonator. Science 327, 1495–1497 (2010) , , , &
- Low threshold gain metal coated laser nanoresonators. Opt. Lett. 33, 1261–1263 (2008) et al.
- Room-temperature subwavelength metallo-dielectric lasers. Nature Photon. 4, 395–399 (2010) et al.
- Subwavelength metal-optic semiconductor nanopatch lasers. Opt. Express 18, 8790–8799 (2010) , &
- Dielectric shielded nanoscale patch laser resonators. Opt. Lett. 36, 1812–1814 (2011) , , &
- Demonstration of a spaser-based nanolaser. Nature 460, 1110–1112 (2009) et al.
- Plasmon lasers at deep subwavelength scale. Nature 461, 629–632 (2009) et al.
- A single-layer wide-angle negative-index metamaterial at visible frequencies. Nature Mater. 9, 407–412 (2010) , , &
- Plasmonics goes quantum. Science 334, 463–464 (2011) &
- Optical microcavities. Nature 424, 839–846 (2003)
- Physics and device applications of optical microcavities. Science 256, 66–70 (1992)
- Analysis of semiconductor microcavity lasers using rate equations. IEEE J. Quantum Electron. 27, 2386–2396 (1991) &
- Subwavelength metallic coaxial waveguides in the optical range: Role of the plasmonic modes. Phys. Rev. B 74, 205419 (2006) , &
- Ultrasmall volume plasmons, yet with complete retardation effects. Phys. Rev. Lett. 101, 163902 (2008) &
- Alloy broadening in photoluminescence spectra of GaxIn1−xAsyP1−y lattice matched to InP. J. Appl. Phys. 75, 2633–2639 (1994) et al.
- Inhibition and enhancement of the spontaneous emission of quantum dots in structured microresonators. Phys. Rev. Lett. 86, 3168–3171 (2001) et al.
- Finite-difference time-domain calculation of the spontaneous emission coupling factor in optical microcavities. IEEE J. Quantum Electron. 35, 1168–1175 (1999) , , , &
- Infrared and optical masers. Phys. Rev. 112, 1940–1949 (1958) &
- Theory of the linewidth of semiconductor lasers. IEEE J. Quantum Electron. 18, 259–264 (1982)
- On the linewidth of microcavity lasers. Appl. Phys. Lett. 60, 304–306 (1992) , &
- Photon statistics of a cavity-QED laser: a comment on the laser-phase-transition analogy. Phys. Rev. A 50, 4318–4329 (1994) &
- Linewidth of four-level microcavity lasers. Phys. Rev. A 59, 2295–2301 (1999) , &
- Quantum fluctuations and saturable absorption in mesoscale lasers. Phys. Rev. A 83, 043827 (2011) &
- Self-tuned quantum dot gain in photonic crystal lasers. Phys. Rev. Lett. 96, 127404 (2006) et al.
- Fundamental formulation for plasmonic nanolasers. IEEE J. Quantum Electron. 45, 1014–1023 (2009) &
- Supplementary Information (1.5M)
This file contains Supplementary Text and Data, Supplementary Figures 1-14 with legends and additional references.