Individual polymer microfibers fabricated by melt electrospinning: optical amplified, full color emission, and good directionality for next flexible excitation sources

Integrated photonic systems would especially benefit from the availability of nano-/microscale laser sources. Single organic polymer micron fiber was successfully fabricated by high voltage melt electrospinning. The single micron fiber indicates a cylindrical structure with smooth surface. By doping different dyes in the polymer fiber, the tunable emission in the whole visible range is realized. In the condition of light pumping, amplified spontaneous emission (ASE) from the three colored micro fibers was studied in detail, they show low thresholds and high gains. In order to investigate the optical feedback cavity, finite difference time-domain (FDTD) simulations were performed to calculate electric field distribution in the microfiber. The cylindrical structure from the fiber confines the light in the cylinder and forms the loop cavity. The micro-cylinder acts like a miniaturized mirrorless cavity, where the emitted light propagates along the helical axis which behaves as a Bragg resonator. The successful fabrication of such microfibers will provide reliable technical support for the realization of intelligent, integrated, low-cost and high-reliability micro-nano laser source devices. (authors)