Amplified spontaneous emission from a single organic microfiber fabricated by melt electrospinning

We study gain amplification processes in a single organic microfiber fabricated by melt electro-spinning method. Smooth, individual and cylindrical fiber is obtained. The gain-induced response of the microfiber is found to depend sensitively on the fiber structure. In the homogeneous single fiber where loop cavity forms, high net optical gain of up to 31.4 cm −1 results in spectral narrowing at the material gain peaks. In the case of strong optical feedback, which occurs in such a long microfiber, amplified spontaneous emission with a low threshold of 0.08 mW is obtained. The low threshold and high gain attribute also to the cylindrical cavity which supplies positive feedback.