In-situ monitoring of optical deposition of carbon nanotubes onto fiber end.

Carbon nanotubes (CNTs) emerged as an attractive material for nonlinear optical devices. Their quasi-one-dimensional structure provided their unique nonlinear characteristics. However, one of their drawbacks is the handling method. We have proposed and demonstrated optical manipulation of CNTs to deposit them onto cores of optical fiber ends with a simple technique. Although the method is very simple, it requires precise control of the optical power. The method does not posses controllability of the CNT-layer properties. In this paper, we employed optical reflectometry to solve these problems. A 15 microm diameter circular region was area-selectively coated by CNTs using highly uniform solution. The preferentially-deposited CNTs were directly, for the first time, observed by a field emission scanning electron microscope (FE-SEM).