Embedded optical micro/nano-fibers for stable devices

We present a technique to embed silica micro and nanofibers in low-index material (Teflon) using an inexpensive and straightforward fabrication process based on spin coating. The optical properties of the silica micro/nano-fibers have been investigated when they are bare or completely or partially embedded. Optical degradation occurs in bare fibers with diameters smaller than twice the wavelength of the guided light, thus making protection through embedding necessary. Our results also show that completely embedded fibers do not degrade over a long time, while partially embedded fibers can preserve the large evanescent waves without undergoing considerable degradation, which would be further reduced or even become negligible with functional overlayers. The results represent a step forward toward the development of durable and stable devices based on optical micro/nano fibers.