TY - GEN
T1 - Antireflection subwavelength gratings on optical fiber tips fabricated by a dedicated UV nano imprint lithography system
AU - Kanamori, Yoshiaki
AU - Okochi, Masaaki
AU - Hane, Kazuhiro
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Antireflection (AR) layers at the tips of optical fibers are indispensable in order to reduce propagation loss and optical noise. Conventional thin-film AR layers have problems about cost due to vacuum apparatus usage in the fabrication and requirement of many thin-film layers to obtain excellent AR characteristics. Thus, easy AR coating methods are needed to reduce Fresnel reflection. AR structures consisting of subwavelength gratings (SWGs), which have periodic structures with the periods smaller than operating wavelengths, have been extensively investigated. Desired refractive index to realize the ideal AR condition can be obtained by SWGs. Nano imprint lithography (NIL) is known as the low cost fabrication technology of SWGs. However, it is difficult to carry out an NIL process on the tips of flexible and long optical fibers. In this study, we developed a dedicated UV-NIL system for optical fiber end-faces. An SWG with a period of 700 nm, a width of 560 nm, and a height of 250 nm was successfully fabricated at the tip of a single-mode optical fiber for optical communications system. We evaluated that reflectance decreased by using the SWG over measured spectral range. For example, reflectance decreased to 0.2% at a wavelength of 1550 nm.
AB - Antireflection (AR) layers at the tips of optical fibers are indispensable in order to reduce propagation loss and optical noise. Conventional thin-film AR layers have problems about cost due to vacuum apparatus usage in the fabrication and requirement of many thin-film layers to obtain excellent AR characteristics. Thus, easy AR coating methods are needed to reduce Fresnel reflection. AR structures consisting of subwavelength gratings (SWGs), which have periodic structures with the periods smaller than operating wavelengths, have been extensively investigated. Desired refractive index to realize the ideal AR condition can be obtained by SWGs. Nano imprint lithography (NIL) is known as the low cost fabrication technology of SWGs. However, it is difficult to carry out an NIL process on the tips of flexible and long optical fibers. In this study, we developed a dedicated UV-NIL system for optical fiber end-faces. An SWG with a period of 700 nm, a width of 560 nm, and a height of 250 nm was successfully fabricated at the tip of a single-mode optical fiber for optical communications system. We evaluated that reflectance decreased by using the SWG over measured spectral range. For example, reflectance decreased to 0.2% at a wavelength of 1550 nm.
KW - Antireflection
KW - nano imprint lithography
KW - optical communications system
KW - optical fibers
KW - subwavelength gratings
UR - http://www.scopus.com/inward/record.url?scp=84927127413&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84927127413&partnerID=8YFLogxK
U2 - 10.1117/12.2075791
DO - 10.1117/12.2075791
M3 - Conference contribution
AN - SCOPUS:84927127413
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - High Contrast Metastructures IV
A2 - Zhou, Weimin
A2 - Koyama, Fumio
A2 - Chang-Hasnain, Connie J.
A2 - Fattal, David
PB - SPIE
T2 - High Contrast Metastructures IV
Y2 - 11 February 2015 through 12 February 2015
ER -