両方向から測定した周波数シフト分布の統合によるブリルアン光相関領域反射計の誤差低減法を提案した論文が Applied Physics Express に掲載されました。横浜国立大学との共同研究の成果です。
Guangtao Zhu, Kohei Noda, Heeyoung Lee, Kentaro Nakamura, and Yosuke Mizuno, “Error compensation in Brillouin optical correlation-domain reflectometry by combining bidirectionally measured frequency shift distributions,” Appl. Phys. Express, vol. 14, no. 5, 052006 (2021).
In standard single-end-access Brillouin optical correlation-domain reflectometry (BOCDR), the systematic error caused by the phase difference between amplitude modulation (AM) and frequency modulation (FM) in the light source can be up to tens of megahertz, causing considerable errors in strain and temperature measurement. In this paper, we develop a new concept of two-end-access BOCDR, in which light is injected into each end of a sensing fiber in turn and the measured results of the Brillouin frequency shift distributions are combined. We numerically show that this configuration can suppress the systematic error caused by the AM-FM phase difference by approximately 90%.