A research group led by Associate Professor Yoshiaki Kanamori and Professor Kazuhiro Hane at Graduate School of Engineering, Tohoku University has developed a technology to fabricate antireflection structures with micro dimples at the tip of optical fibers.  Optical fibers have been used for optical communications and components of photometric analyzer.  In order to reduce connection loss with optical components such as light source, photo-sensitive element and lenses, antireflection films are fabricated at the tip of optical fibers. However, the cost issue remains because conventional antireflection films are developed using a vacuum device.　

 Using a nano-imprint technology, the research group successfully reduced reflection loss by making micro conical dimples at the core of optical fiber tip at intervals of 270 nanometers.  A nano-imprint technology allows to copy micropatterns by pressing an original plate into applied polymers on the substrate, and helps develop nanostructures at a lower cost without expensive exposure or vacuum devices.  In this study, a dedicated nano-imprint machine to fabricate nanostructures at the tip of optical fibers was developed.  When dimples are at narrower intervals than optical wavelengths, a refraction index changes and wave reflection is prevented.  Shapes, intervals and heights of dimples determine a reflectance and wavelength bands, which increases possibilities of design compared to conventional antireflection films.  It is possible to fabricate different films to meet various demands.

 The achievement will be presented at the 23rd International Microprocesses and Nanotechnology Conference in Kokura, Kitakyushu on November 12, 2010.

More Information (Japanese)

[Contact]
Associate Professor Yoshiaki Kanamori
Graduate School of Engineering, Tohoku University
TEL: +81-22-795-6965
E-mail: kanamori*hane.mech.tohoku.ac.jp (Replace * with @)