Compact polarization splitter based on silicon grating-assisted couplers.
Compact polarization beam splitter (PBS) based on grating-assisted couplers is proposed by utilizing contra-directional coupling between two corrugated strip waveguides. The co-directional coupling in the device is greatly suppressed by the designed asymmetric structure. The phase matching condition is only satisfied for TE polarization at the central wavelength of 1550 nm by a spatially periodic refractive-index perturbation. Due to the contra-directional coupling, the device breaks the limit of the precise control of the coupling strength and length. The simulation results show that the presented PBS, with a coupling length of only 19 μm, has a broad working bandwidth (∼40  nm) for a crosstalk below -12  dB. A large fabrication tolerance (±40  nm) for the waveguide width is also achieved.
Huiye
H
Qiu
Yuxia
Y
Su
Ping
P
Yu
Ting
T
Hu
Jianyi
J
Yang
Xiaoqing
X
Jiang