Silica taper incorporated polymer micro or nanofibers have been fabricated by direct drawing. This method could provide stable and high-optical-coupling efficiency. The as-fabricated polymethyl methacrylate (PMMA) fibers not only show low-optical losses, but also offer good flexibility, making them promising elements for sharp-bending waveguides and ring resonators. A low-loss microcoupler has been assembled with two 860-nm diameter PMMA fibers and a polymeric knot resonator with a loaded Q-factor of about 3000 has been assembled using a 3-mu m-diameter PMMA microfiber. Thermostability of the PMMA fibers has also been investigated. (C) 2008 Wiley Periodicals, Inc. J Appl Polymer Sci 110:1080-1084, 2008