両側波帯変調器を用いた外部変調ブリルアン光相関領域反射計のノイズ発生機構を解明した菊地啓太君（M1）の論文が、Japanese Journal of Applied Physics に掲載されました。
K. Ozaki*, K. Kikuchi*, G. Zhu, K. Noda, Y. Yao, Y. Lu, R. Jha, H. Lee, and Y. Mizuno, “Noise mechanism clarification in external-modulation Brillouin optical correlation-domain reflectometry with double-sideband modulator,” Jpn. J. Appl. Phys., vol. 63, no. 7, 070904 (2024). *Co-first authors
Brillouin optical correlation-domain reflectometry (BOCDR) allows for relatively high spatial resolution and random accessibility with single-end light injection into the sensing fiber. Typically, BOCDR relies on directly modulating the laser diode’s driving current, which facilitates sinusoidal frequency modulation for distributed sensing but also introduces unintended power modulation that can degrade performance. To address these power variations, external-modulation BOCDR using a double-sideband modulator has been developed. However, this method generates substantial noise, overpowering the Brillouin signal and impeding accurate strain and temperature measurements. This study clarifies the previously unexplained noise mechanisms and suggests system design optimizations to mitigate their impact.