Design and Fabrication of Tunable Wide-Angle Optical Polarization Splitter
Date Issued
2004
Date
2004
Author(s)
Lin, Chia-Wei
DOI
zh-TW
Abstract
A tunable wide-angle optical polarization splitter, consisting of a mode converter and a polarization splitter, is demonstrated. The splitter is essentially an asymmetric Y- junction waveguide. To reduce the device length, the bending branch of the Y-junction is replaced by simplified coherently-coupled waveguide segments. To improve the poor confinement of waveguide made by Ni diffusion, a small amount of Zn is added to Ni as the diffusion source. By trial and error, the coupling length of waveguide segments is found to be 350μm. In particular, when the total bending angle is 4°, the bending angles of the segments are designed as 1°, 3°, 4°, 3°, and 1° according to the simplified coherent coupling (SCC) theory. That results in a separation distance of about 195μm for the two output branches, which is advantageous for fiber connection. The measured extinction ratios of the optical polarization splitter are 27.6dB and 24.8dB for the TE- and TM-branch, respectively. So far, those are the best results reported for wide-angle optical polarization splitter. To use the strong electro-optic (EO) effect of LiNbO3, the polarization splitter is implemented on a Z-cut X-propagation LiNbO3 substrate. With an applied voltage of 100V, the measured tunability of TE/TM modal power conversion is 43%, which is the first result reported for tunable wide-angle optical polarization splitter.
Subjects
簡式同調耦合結構
模態轉換器
鋅鎳金屬擴散式光波導
模態檢選效應
simplified coherently-coupled waveguide
mode converter
extinction ratios
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-93-R91941013-1.pdf
Size
23.31 KB
Format
Adobe PDF
Checksum
(MD5):80a2772085300a74d45716a4da41a256