Speaker
Rattanachai Kowong
(Department of Industrial Physics and Medical Instrumentation, Faculty of Applied Science, Lasers and Optics Research Group (LANDOS), Science and Technology Institute, King Mongkut's University of Technology North Bangkok)
Description
We propose a new approach, the Arc Discharge Drawing (ADD) technique, to
fabricate silica fibers with diameters less than the wavelength of commercial
available lasers. With this single-step technique, silica wires with diameters
as small as 50 nm were demonstrated. This technique would provide an attractive
alternative to current approaches to fabricate the silica nanowires. For ADD
technique, a standard optical fiber is placed in two fiber mounts. One of the
fiber mount performs as the computer-controlled stage that pulls the fiber at
various speeds in the range of 2 mm/s to 15 mm/s. During this computer-controlled
fiber drawing process, the fiber is heated by the arc discharge serving as the
heat source. The arc discharge is supplied with a D.C. current from a rectifier
with a controlled voltage to 20 kV. The nanowires can be fabricated by varying
the voltage in the range of 4 kV to 5 kV. The optimum operational voltage is
determined by the scanning electron microscope (SEM) images of the fabricated
silica nanowires. Based on the SEM images, it is evident that nanowires obtained
by the ADD technique exhibit great diameter uniformity and large length. In
addition, the fabricated silica nanowires are flexible due to their large aspect
ratio between the diameter and the length. Furthermore, the nanowires can be bent
and twisted without breaking.The bent and twisted silica nanowires are
extremely useful to guide laser light for small scale photonic devices. In this
study, the nanowires obtained by ADD technique were also investigated in the
aspect of guiding 633-nm wavelength light. The results reveal the high
transmission losses thus providing the greater evanescent field. This represents
a significant advancement in the field of nanophotonics. Due to their
extraordinary compactness and excellent optical properties, nanowires will find a
whole range of nanoscale photonic devices.
Author
Rattanachai Kowong
(Department of Industrial Physics and Medical Instrumentation, Faculty of Applied Science, Lasers and Optics Research Group (LANDOS), Science and Technology Institute, King Mongkut's University of Technology North Bangkok)
Co-authors
Prof.
Amarin Ratanavis
(Department of Industrial Physics and Medical Instrumentation, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok 10800 Thailand)
Mr
Wuttichai Putchana
(Department of Industrial Physics and Medical Instrumentation, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok 10800 Thailand)
