Beam bending via plasmonic lenses.

We have designed and characterized three different types of plasmonic lenses that cannot only focus, but can also bend electromagnetic (EM) waves. The bending effect is achieved by constructing an asymmetric phase front caused by varying phase retardations in EM waves as they pass through a plasmonic lens. With an incident wave normal to the lens surface, light bends up to 8° off the axial direction. The optical wave propagation was numerically investigated using the finite-difference time-domain (FDTD) method. Simulation results show that the proposed plasmonic lenses allow effective beam bending under both normal and tilted incidence. With their relatively large bending range and capability to perform in the far field, the plamsonic lenses described in this article could be valuable in applications such as photonic communication and plasmonic circuits.

[1]  F. Fang,et al.  Experimental investigation of superfocusing of plasmonic lens with chirped circular nanoslits. , 2010, Optics express.

[2]  Zhijun Sun,et al.  Refractive transmission of light and beam shaping with metallic nano-optic lenses , 2004 .

[3]  L. Lim,et al.  Plasmonic microzone plate: Superfocusing at visible regime , 2007 .

[4]  Alexei A. Maradudin,et al.  Excitation of surface polaritons by end-fire coupling. , 1983, Optics letters.

[5]  Chunlei Du,et al.  Focal length modulation based on a metallic slit surrounded with grooves in curved depths , 2007 .

[6]  R. W. Christy,et al.  Optical Constants of the Noble Metals , 1972 .

[7]  Y. Wang,et al.  Flying plasmonic lens in the near field for high-speed nanolithography. , 2008, Nature nanotechnology.

[8]  D. Pile,et al.  Channel plasmon-polariton in a triangular groove on a metal surface. , 2004, Optics letters.

[9]  L. Martín-Moreno.  Plasmonic circuits: Detecting unseen light , 2009 .

[10]  Uriel Levy,et al.  Demonstration of nanofocusing by the use of plasmonic lens illuminated with radially polarized light. , 2009, Nano letters.

[11]  L. Verslegers,et al.  Planar lenses based on nanoscale slit arrays in a metallic film , 2009, 2009 Conference on Lasers and Electro-Optics and 2009 Conference on Quantum electronics and Laser Science Conference.

[12]  Ewold Verhagen,et al.  Nanofocusing in laterally tapered plasmonic waveguides. , 2008, Optics express.

[13]  Richard R. Grote,et al.  Integrated plasmonic lens photodetector , 2009 .

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

[15]  Byoungho Lee,et al.  The use of plasmonics in light beaming and focusing , 2010 .

[16]  Weibin Chen,et al.  Experimental confirmation of miniature spiral plasmonic lens as a circular polarization analyzer. , 2010, Nano letters.

[17]  Byoungho Lee,et al.  Off-axis directional beaming of optical field diffracted by a single subwavelength metal slit with asymmetric dielectric surface gratings , 2007 .

[18]  Harry A. Atwater.  The promise of plasmonics. , 2007 .

[19]  Zhaowei Liu,et al.  Focusing surface plasmons with a plasmonic lens. , 2005, Nano letters.

[20]  Sergey I. Bozhevolnyi,et al.  Extraordinary optical transmission enhanced by nanofocusing. , 2010, Nano letters.

[21]  Ann Roberts,et al.  Plasmonic lenses formed by two-dimensional nanometric cross-shaped aperture arrays for Fresnel-region focusing. , 2010, Nano letters.

[22]  H. Raether.  Surface Plasmons on Smooth and Rough Surfaces and on Gratings , 1988 .

[23]  Xiang Zhang,et al.  Tuning the focus of a plasmonic lens by the incident angle , 2006 .

[24]  Recording Bessel-like beam shapes generated by plasmonics lens. , 2009, Optics express.

[25]  Reuven Gordon,et al.  Increased cut-off wavelength for a subwavelength hole in a real metal. , 2005, Optics express.

[26]  Weibin Chen,et al.  Miniature circular polarization analyzer with spiral plasmonic lens. , 2009, Optics letters.