Chalcogenide ( ${\mathrm{As}}_2{\mathrm{S}}_3$ ) nanofibers as narrow as $200\mathrm{nm}$ in diameter are drawn by the fiber pulling method, are successfully embedded in SU8 polymer, and form on-chip waveguides and high-Q microknot resonators ( $Q=3.9\times {10}^4$ ) with smooth cleaved end faces. Resonance tuning of resonators is realized by localized laser irradiation. Strong supercontinuum generation with a bandwidth of $500\mathrm{nm}$ is achieved in a 7-cm-long on-chip chalcogenide waveguide. Our result provides a method for the development of compact, high-optical-quality, and robust photonic devices.