Side-Illumination Fluorescence Dye-Doped-Clad PMMA-Core Polymer Optical Fiber: Potential Intrinsic Light Source for Biosensing

A specially designed laser-dye-doped polymer optical fiber (POF) was drawn and investigated experimentally. The cladding of the POF was doped with Rhodamine 640 and pumped with a compact and low-cost 532-nm diode-pumped solid-state laser. By using the side-illumination fluorescence technique, any section along the POF can act as an intrinsic light source. The fluorescence power of the dye-doped POF under side-illumination was improved by more than 10 times by a bending method. With this enhancement, the issue of coupling light into the POF becomes simpler, cheaper, and more consistent, constructing a practical platform for a sensing system.