Measurement of the intermodal crosstalk of a bent multimode waveguide.
We quantitatively investigate the main source of the intermodal crosstalk of a silicon-based bent multimode waveguide by experiment. The measurement is performed through time-domain scanning low-coherence interferometry. From the measurement results, one can not only calculate the modal crosstalk, but can also locate the position where the crosstalk appears. The results indicate that the modal mismatch at the points where the curvature of the waveguide changes is the main origin of the modal crosstalk. For a two-mode waveguide with a bending radius of 5 μm at 1310 nm, the crosstalk is as high as -20 and -16  dB for the fundamental and first-order mode, respectively. This work gives us a deep insight into how the guided modes actually propagate through the bent waveguide.
Jian
J
Wang
Changyun
C
Zhao
Bing
B
Wei
Wang
W
Gencheng
Tingge
T
Dai
Yuehai
Y
Wang
Xiaoqing
X
Jiang
Yubo
Y
Li
Jianyi
J
Yang