Title :
Theoretical Study on Surface Mode in Photonic Crystal Fishbone Nanocavity
Author :
Tsan-Wen Lu ; Po-Tsung Lee
Author_Institution :
Dept. of Photonics, Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
We propose and theoretically investigate a novel 1-D photonic crystal fishbone (FB) that can sustain surface waves. By designing a nanocavity in an FB, the confined surface mode with a high quality factor (~ 105) and extremely concentrated field near the FB surface (small mode volume, ~ 2.3 × 10-2 (λ/2)3) cause strong interactions between light and the surrounding medium for optical sensing and manipulation. In simulation, as an optical sensor, the proposed design achieved a high index sensitivity of 650 nm/RIU and minimum detectable index variation of 2 × 10-5. As optical tweezers, a simulated injected optical threshold power of only 80 μW is needed for stably trapping a polystyrene sphere (PS) 100 nm in diameter. In addition, a method of selectively trapping a PS of specific size is theoretically proposed via our design. We believe that our proposed FB nanocavity with a surface mode would provide enhanced features for on-chip optical sensors and tweezers.
Keywords :
Q-factor; nanophotonics; nanosensors; optical polymers; optical sensors; photonic crystals; radiation pressure; 1D photonic crystal fishbone nanocavity; concentrated field; confined surface mode; detectable index variation; high index sensitivity; mode volume; optical manipulation; optical sensor; optical trapping; optical tweezers; polystyrene sphere; power 80 muW; quality factor; simulated injected optical threshold power; size 100 nm; surface waves; Charge carrier processes; Indexes; Optical sensors; Optical surface waves; Optical waveguides; Photonic crystals; Surface waves; Nanocavity; nanocavity; optical sensors; optical tweezers; photonic crystals; surface wave;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2015.2474372