光ファイバに沿った偏光状態の分布を計測できる新たな方式「偏波光相関領域反射計（POCDR）」の提案に関する東工大・横浜国大との共同研究の成果が Journal of Lightwave Technology に掲載されました。
K. Noda, H. Lee, K. Nakamura, and Y. Mizuno, “Proposal of polarization optical correlation-domain reflectometry (POCDR),” J. Lightwave Technol., vol. 40, no. 16, pp. 5708-5715 (2022).
Brillouin optical correlation-domain reflectometry (BOCDR) is known as one of the distributed fiber-optic strain/temperature sensing techniques. Recently, a high-speed BOCDR configuration with no measurable strain limit has been developed, but only a sampling rate of 50 Hz has been experimentally demonstrated, limited by the use of a commercial microwave frequency sweeper (MFS). In this work, by replacing the MFS with an independent voltage-controlled oscillator driven by a function generator, we experimentally show via vibration detection that this system can achieve a sampling rate of up to 20 kHz. We newly observe the systematic noise peculiar to such high-speed operation, which is found to originate from the unintended intensity modulation of the laser output. We also demonstrate the suppression of this noise by band-elimination filtering.