Semiconductor plasmon laser

Laser science has tackled physical limitations to achieve higher power, faster and smaller light sources. The quest for ultra-compact laser that can directly generate coherent optical fields at the nano-scale, far beyond the diffraction limit of light, remains a key fundamental challenge. Microscopic lasers based on photonic crystals3, metal clad cavities4 and nanowires can now reach the diffraction limit, which restricts both the optical mode size and physical device dimension to be larger than half a wavelength. While surface plasmons are capable of tightly localizing light, ohmic loss at optical frequencies has inhibited the realization of truly nano-scale lasers. Recent theory has proposed a way to significantly reduce plasmonic loss while maintaining ultra-small modes by using a hybrid plasmonic waveguide. Using this approach, we report an experimental demonstration of nano-scale plasmonic lasers producing optical modes 100 times smaller than the diffraction limit, utilizing a high gain Cadmium Sulphide semiconductor nanowire atop a Silver surface separated by a 5 nm thick insulating gap. Direct measurements of emission lifetime reveal a broad-band enhancement of the nanowire's exciton spontaneous emission rate up to 6 times due to the strong mode confinement and the signature of apparently threshold-less lasing. Since plasmonic modes have no cut-off, we show downscaling of the lateral dimensions of both device and optical mode. As these optical coherent sources approach molecular and electronics length scales, plasmonic lasers offer the possibility to explore extreme interactions between light and matter, opening new avenues in active photonic circuits, bio-sensing and quantum information technology.

[1]  Federico Capasso,et al.  Laser action in nanowires: Observation of the transition from amplified spontaneous emission to laser oscillation , 2008 .

[2]  Mehdi Khoshnevissan Threshold characteristics of multimode laser oscillators , 1987 .

[3]  M. Lukin,et al.  Generation of single optical plasmons in metallic nanowires coupled to quantum dots , 2007, Nature.

[4]  Xiang Zhang,et al.  Observation of stimulated emission of surface plasmon polaritons. , 2008, Nano letters.

[5]  David A. Ritchie,et al.  THz and sub‐THz quantum cascade lasers , 2009 .

[6]  D. Bergman,et al.  Surface plasmon amplification by stimulated emission of radiation: quantum generation of coherent surface plasmons in nanosystems. , 2003, Physical review letters.

[7]  Kelly P. Knutsen,et al.  Single gallium nitride nanowire lasers , 2002, Nature materials.

[8]  Charles M. Lieber,et al.  Single-nanowire electrically driven lasers , 2003, Nature.

[9]  G. W. Ford,et al.  Electromagnetic interactions of molecules with metal surfaces , 1984 .

[10]  Gunnar Björk,et al.  Analysis of semiconductor microcavity lasers using rate equations , 1991 .

[11]  G. G. Qin,et al.  Enhancement-mode metal-semiconductor field-effect transistors based on single n-CdS nanowires , 2007 .

[12]  J. Gordon,et al.  The Maser—New Type of Microwave Amplifier, Frequency Standard, and Spectrometer , 1955 .

[13]  Xiang Zhang,et al.  Subwavelength discrete solitons in nonlinear metamaterials. , 2007, Physical review letters.

[14]  Rupert F. Oulton,et al.  Confinement and propagation characteristics of subwavelength plasmonic modes , 2008 .

[15]  R. Renner,et al.  Measurement of the diffusion-length of carriers and excitons in CdS using laser-induced transient gratings , 1988 .

[16]  Dirk Englund,et al.  Ultrafast photonic crystal nanocavity laser , 2006 .

[17]  Harry A. Atwater,et al.  Local detection of electromagnetic energy transport below the diffraction limit in metal nanoparticle plasmon waveguides , 2003, Nature materials.

[18]  Ferenc Krausz,et al.  X-ray Pulses Approaching the Attosecond Frontier , 2001, Science.

[19]  Jeffrey N. Anker,et al.  Biosensing with plasmonic nanosensors. , 2008, Nature materials.

[20]  Masanobu Haraguchi,et al.  Theoretical and experimental investigation of strongly localized plasmons on triangular metal wedges for subwavelength waveguiding , 2005 .

[21]  T. Ebbesen,et al.  Channel plasmon subwavelength waveguide components including interferometers and ring resonators , 2006, Nature.

[22]  Volker J. Sorger,et al.  A hybrid plasmonic waveguide for sub-wavelength confinement and long range propagation , 2008 .

[23]  Yu. A. Pashkin,et al.  Single artificial-atom lasing , 2007, Nature.

[24]  E. Purcell Spontaneous Emission Probabilities at Radio Frequencies , 1995 .

[25]  D. G. Thomas,et al.  Optical Properties of Bound Exciton Complexes in Cadmium Sulfide , 1962 .

[26]  M. Smit,et al.  Lasing in metallic-coated nanocavities , 2007 .

[27]  M. Stockman,et al.  Nanofocusing of optical energy in tapered plasmonic waveguides. , 2004, Physical review letters.

[28]  V. Podolskiy,et al.  Stimulated emission of surface plasmon polaritons , 2008, 2008 Conference on Lasers and Electro-Optics and 2008 Conference on Quantum Electronics and Laser Science.