Organic Photodetector Directly Deposited onto the Cut End of a Plastic Optical Fiber

We propose a system where an Organic PhotoDetector (OPD) is realized directly onto the cleaved surface of a standard polymethylmethacrylate (PMMA)-based Plastic Optical Fiber (POF). The OPD photoactive layer is based on the bulk-heterojunction of [6,6]-phenyl-C61-butyric acid methyl ester with a squaraine dye, whose absorption spectrum well matches the POF minimum loss window in the red (around 650nm). The device is realized by consecutively depositing the solution-processed transparent anode on the fiber surface, the solution-processed active layer and the evaporated aluminum cathode. When tested with monochromatic pulsed light at a wavelength of 660nm, the POF-OPD system showed the capability of operating up to a 10MHz repetition frequency, not far from the POF intrinsic bandwidth limitation. This promising result represents a first step towards the development of all-organic integrated optical data links.