Research Of Subwavelength Focusing Effect Of Light By A Tapered Micro-nano Tube And Its Application

Based on the subwavelength focusing effect of light by a tapered micro-nano tube, we did further research and application experiments.First, we analyzed the theory of subwavelength focusing by direct synthesis of the angular spectrum of plane waves and how the taper of micro-nano tube affected its subwavelength focusing effect, to explore the theory of subwavelength focusing effect of light by a tapered micro-nano tube.Second, we applied the subwavelength focusing effect of light by a tapered micro-nano tube in scanning nanowires. The digital simulation and experimental observations showed that the tapered micro-nano tube had good non-near-field scanning capability, which has a good prospect in image biological molecules and micro-structured surface probe.At last, we propose a new mechanism for far-field subwavelength focusing at optical frequencies based on the use of a tapered micro-nano tube coated with metal film. We found that it significantly improved the subwavelength focusing effect of the tapered micro-nano tube, which we gave the experiment and analysis.