Writing and readout of luminescent defects on an optical nanofiber using an electron beam

Abstract

We demonstrate the writing and readout of groups of luminescent defects on an optical nanofiber (ONF), with readout performed through the fiber modes. In the write step, a focused electron beam incident on the fiber surface created luminescent defect centers in the fiber's silica in a region of diameter $\sim200$ nm localized about the beam center. In the readout step, the electron beam was scanned over the fiber and the induced cathodoluminescence from the defects was coupled into the ONF and detected. The regions with electron beam-induced luminescent defects exhibited a strongly enhanced optical signal, despite minimal observable change in the fiber surface, as judged by secondary electron imaging over the same region. Spectral measurements show that the enhanced luminescence stems from the creation of both oxygen deficiency centers (ODCs) and non-bridging oxygen hole centers (NBOHCs) by the electron beam.