By Topic

Novel Silica-Based Waveguide-Type Polarization Beam Splitters Using Trenches Filled With Low-Refractive-Index Material

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Ito, J. ; Dept. of Sci. & Technol., Keio Univ., Yokohama, Japan ; Tsuda, H.

We have proposed and fabricated two kinds of planar-lightwave-circuits-type polarization beam splitters (PBSs) using trenches filled with low-refractive-index material: a narrowband-type and a wideband-type. Both PBSs consisted of two 3-dB couplers and two waveguide arms with trenches of different lengths. A narrowband-type PBS used silica-based waveguides on silica substrates. On the other hand, a wideband-type PBS used silica-based waveguides on silicon. The local lateral refractive index difference (??) was increased by introducing a pair of trenches. Due to the local lateral enhanced optical confinement structure, the propagation constants of waveguides constructed using trenches filled with a low-refractive-index material depend strongly on the polarization. A narrowband-type PBS, which had the same arm lengths can have a high polarization extinction ratio, although the working bandwidth is restricted. However, a wideband-type PBS, which had the different arm lengths can function over a broad wavelength range, provided that the maximum polarization extinction ratio is acceptable. We optimized the structures of both types of PBS by carrying out simulations. In these simulations, the narrowband-type PBS exhibited a maximum polarization extinction ratio of -34.5 dB for the through-path at 1555 nm, -42.7 dB for the cross-path at 1545 nm, whereas the wideband-type PBS exhibited a -10 dB polarization extinction ratio bandwidth of 105 nm. Our fabricated narrowband-type PBS exhibited a -10 dB polarization extinction ratio bandwidth of 45 nm for both the through-path and the cross-path. At this bandwidth, the insertion loss was less than 9.0 dB. The maximum polarization extinction ratio was -28.9 dB for the through-path at 1570 nm, and -27.5 dB for the cross-path at 1535 nm.

Published in:

Lightwave Technology, Journal of  (Volume:27 ,  Issue: 24 )