[1] Lehigh Univ, Dept Elect & Comp Engn, Bethlehem, PA 18015 USA
[2] Lehigh Univ, Ctr Opt Technol, Bethlehem, PA 18015 USA
[3] Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA
[4] Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA
[5] Natl Chiao Tung Univ, Dept Photon, Hsinchu 30010, Taiwan
[6] Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3AA, S Glam, Wales