菊地君（M2）の成果が Journal of Lightwave Technology に受理されました。

ブリルアン光相関領域反射計の世界最高空間分解能を達成した菊地君（M2、横浜国大特別研究学生、芝浦工大）の論文が、Journal of Lightwave Technology に受理されました。

K. Kikuchi, H. Lee, R. Ohata, K. Noda, R. Inoue, and Y. Mizuno, “BOCDR achieving 6-mm spatial resolution at modulation frequencies close to Brillouin bandwidth,” J. Lightwave Technol., accepted.

This study experimentally investigates the operation of Brillouin optical correlation-domain reflectometry (BOCDR) at modulation frequencies near the Brillouin bandwidth, typically several tens of megahertz for silica fibers, where no prior experimental verification has been reported despite its potential to enhance spatial resolution. Observations of the Brillouin gain spectrum (BGS) revealed that periodic components originating from the modulation frequency appeared when the frequency exceeded approximately 25 MHz. In BOCDR, where the Brillouin frequency shift (BFS) is obtained from the BGS peak frequency, such periodic components may degrade strain- and temperature-measurement accuracy. First, distributed temperature measurements were demonstrated at a spatial resolution of 8.5 mm using the highest modulation frequency (~20 MHz) without periodic components, detecting a temperature change over a 9 mm section. The effect of periodic components on temperature measurements was then examined, showing that they deteriorate the linearity of the BFS-temperature dependence. Furthermore, by suppressing these components via signal processing, linearity was maintained even at modulation frequencies above ~30 MHz, enabling distributed measurements. Finally, by applying the suppression method at ~40 MHz, distributed strain and temperature measurements were achieved with a world-record spatial resolution of 6 mm. This experimental verification of BOCDR spatial resolution is expected to contribute to further performance improvements.