Generating micropatterns onto the core of an optical fiber end with nanoparticles using fiber modes

In this paper we report an experimental study to generate micropatterns of nanoparticles using modes that propagate into optical fiber and the photodeposition technique. The different modes for instance LP01, LP11, LP21 and TM01 are obtained by performing a mechanical adjustment in an experimental setup. Subsequently, we placed the optical fiber end into a colloidal solution to adhere the nanoparticles on the core of the optical fiber end. The colloidal solution is composed by nanoparticles, such as gold, silver, zinc or single wall carbon nanotubes suspended in ethanol. The experimental results show that it is possible to obtain microscale patterning of nanoparticles in areas less than 10 µm (diameter of optical fiber core). Furthermore, these micropatterns get the shape of the transversal mode that is propagated in the optical fiber. To the best of our knowledge, generating micropatterns onto an optical fiber end using fiber modes is demonstrated for the first time. The ability to pattern the optical fiber end with nanoparticles could enable several applications, for instance in the sensing based on localized surface plasmon resonance or in the manipulation of nano or micro-objects using micro-hotspots or temperature gradients.