Optical properties of quantum-dot-decorated polymer nanofibers

Optical waveguiding properties of colloidal quantum dots doped polymer microfibers

QDs-doped polymer microfibers are fabricated through direct drawing method. By adding the polymethylmethacrylate into polystyrene, the surface quality and flexibility of microfiber are improved. Under direct excitation by the focused laser, the polymer microfibers doped with different quantum dots emit different colors and act as an optical waveguide. The waveguide properties of the microfiber are studied in detail. It is found that refractive index of the substrate and diameter of microfiber are the most important factors that affect the optical loss of this waveguide. The microfiber does not produce significant polarization after being deposited on the substrate. Moreover, exciting the QDs-doped polymer microfiber through a blue LED is demonstrated. This structure may find widespread applications in integrated photonic devices.

Gold nanorod-enhanced light emission in quantum-dot-doped polymer nanofibers

One-dimensional nanomaterials have attracted great interest in both fundamental research and technological applications because they can function as device elements and be used to effectively generate, guide, and detect light. Here we report a gold nanorod-enhanced light emission in quantum-dot-doped polymer nanofibers. By incorporating gold nanorods into quantum-dot-doped polymer nanofiber, a 67% increment in 600 nm red light emission efficiency was obtained with an extinction coefficient of 100 cm(-1), a low excitation power operation of 100 nW, and a 100 min increment in photostability.

Wavelength-converted wave-guiding in dye-doped polymer nanofibers

Nanoscale wavelength-converted optical components are promising components for communication and optical information processing in integrated photonic system. In this work, we report a facile strategy for realizing continuously tunable wavelength-converted wave-guiding in dye-doped nanofibers. The nanofibers with diameters of 200–800 nm have an absorption coefficient of about 80 cm⁻¹ and a self-absorption coefficient of about 30 cm⁻¹, and exhibit relatively high PL efficiency and high photobleaching resistance under an optical pump. By launching the pump light into the nanofibers, the excited light in the nanofibers got self-absorption and reemitted at a longer wavelength, resulting in a gradual wavelength conversion during propagation. On the basis of this wavelength-converted wave-guiding, nanoscale wavelength-converted splitters were demonstrated by assembling the nanofibers into crossed structures. We believe that the dye-doped nanofibers would bring new exciting opportunities in developing new wavelength-converted optical components for nanophotonic device integration.

Active nanowaveguides in polymer doped with CdSe-ZnS core-shell quantum dots

We report a strategy for the fabrication of active nanowaveguides (nanoWGs) in polymer doped with CdSe-ZnS core-shell quantum dots (QDs). The nanoWGs, with an absorption coefficient of 247 cm(-1) and a self-absorption coefficient of 77 cm(-1), were fabricated by a direct drawing method. The characterization indicates that the nanoWGs, in which the QDs act as nanoemitters under an optical pump, exhibit high photoluminescence efficiency and high photobleaching resistance. The QD-doped polymer nanoWGs would be a promising active waveguide for miniaturized nanophotonic integration.