Single-mode fiber with a plano-convex silicon microlens for an integrated butt-coupling scheme.
A single-mode fiber with plano-convex silicon microlens is proposed for butt-coupling between single-mode fibers and high-index-contrast waveguides with fine mode-field diameter. The lensed fiber has two specific features, high focusing power, and null working distance. The theoretical focus-spot diameter at the endface of the lensed fiber is calculated to be as small as 0.56 microm at a wavelength 1.55 microm. A simple fabrication method for the lensed fiber employing chemical etching and rf-sputtering is presented. Experiments showed that the mode-field-diameter of a single-mode fiber was successfully contracted from 10.5 to 1.3 microm with the lensed fiber.
Shiraishi
Kazuo
K
Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Japan. kazuos@cc.utsunomiya-u.ac.jp
Kagaya
Makoto
M
Muro
Koichi
K
Yoda
Hidehiko
H
Kogami
Yoshinori
Y
Tsai
Chen S
CS