Newly Developed Optical Fiber Line Testing System Employing Bi-Directional OTDRs for PON and In-Service Line Testing Criteria. - Yusuke Koshikiya; Noriyuki Araki; Hisashi Izumita; Fumihiko Ito (IEICE Trans. Commun., 2007)

Identification of high-PMD sections along installed optical cables with long range OFDR. - Fumihiko Ito; Xinyu Fan; Yusuke Koshikiya (OFC/NFOEC, 2013)

Identification of loss factors by evaluating backscattered modal loss ratio obtained with 1-µm-band mode-detection OTDR. - Atsushi Nakamura; Keiji Okamoto; Yusuke Koshikiya; Tetsuya Manabe; Manabu Oguma; Toshikazu Hashimoto; Mikitaka Itoh (OFC, 2015)

Proactive Detection of Optical Cable Failure Caused by Water Freezing Using 1-μm-band Mode-Detection OTDR. - Atsushi Nakamura; Yusuke Koshikiya; Tetsuya Manabe (OFC, 2018)

Branching Ratio Design of Optical Coupler for Cable Re-Routing Operation Support System with No Service Interruption. - Hiroshi Watanabe; Kazutaka Noto; Yusuke Koshikiya; Tetsuya Manabe (IEICE Trans. Commun., 2018)

Potential Fault Detection in Optical Cables Using OTDR Operating in Two-Modes. - Atsushi Nakamura; Keiji Okamoto; Yusuke Koshikiya; Tetsuya Manabe (OECC/PSC, 2019)

Distributed Vibration Sensing of Seismic Event by Optical Frequency Domain Reflectometry. - Tatsuya Okamoto; Daisuke Iida; Yusuke Koshikiya; Nazuki Honda (ECOC, 2021)

Method of Estimating Inter-Core Crosstalk for Constructing Uncoupled Multi-Core Fiber Transmission Line. - Atsushi Nakamura; Tomokazu Oda; Yusuke Koshikiya (OFC, 2022)

Wideband Impulse Response Measurement of Coupled 2-Core Fibers of Various Lengths employing Dual-Comb Coherent Sampling. - Masafumi Uyama; Masaki Uno; Shuki Okamura; Chao Zhang; Fumihiko Ito; Atsushi Nakamura; Tatsuya Okamoto; Yusuke Koshikiya (OFC, 2022)

Method of widening dynamic range of measurable vibration in FDM-based sampling-rate-enhanced ϕ-OTDR. - Yoshifumi Wakisaka; Daisuke Iida; Hiroshi Takahashi; Yusuke Koshikiya (OFC, 2022)

Fast BOTDA acquiring method based on broadband light as a probe signal. - Takahiro Ishimaru; Yoshifumi Wakisaka; Hiroshi Takahashi; Daisuke Iida; Yusuke Koshikiya (OFC, 2023)

Bending Radius Dependence of Power Coupling Coefficient and Spatial Mode Dispersion in Coupled Multi-Core Fibers. - Masaki Nakamori; Atsushi Nakamura; Masaharu Ohashi; Yusuke Koshikiya (OFC, 2023)

Definition of Mode Field Diameter for Few-Mode Fibers based on Stationary Expression of Propagation Constant. - Atsushi Nakamura; Masaharu Ohashi; Yusuke Koshikiya (OFC, 2023)

Frequency averaging with rotation angle tracking technique in phase-OTDR DAS for large-scale vibration measurement. - Yoshifumi Wakisaka; Hiroshi Takahashi; Daisuke Iida; Takahiro Ishimaru; Yusuke Koshikiya (OFC, 2023)

Cryptographic Key Generation Using Conventional Single-Mode Fiber and an Optical Time Domain Reflectometer. - Yuto Sagae; Atsushi Nakamura; Takayoshi Mori; Yusuke Koshikiya; Kazuhide Nakajima (OFC, 2024)

Simultaneous monitoring of 8 fiber routes by means of high-speed switching for time-sharing FDM-DAS. - Hiroshi Takahashi; Yoshifumi Wakisaka; Takahiro Ishimaru; Chihiro Kito; Keisuke Murakami; Daisuke Iida; Yusuke Koshikiya; Kunihiro Toge (OFC, 2025)

First Field Demonstration of Diagnosis of Aerial Telecom Facilities by Using High-Precision Φ-OTDR DAS. - Yoshifumi Wakisaka; Hiroshi Takahashi; Takahiro Ishimaru; Daisuke Iida; Keisuke Murakami; Chihiro Kito; Yusuke Koshikiya; Kunihiro Toge (OFC, 2025)

Simultaneous Measurement of Differential Modal Group Delay in Few-Mode Fibers on the Basis of Optical Time Domain Reflectometer with Delay Lines. - Masaki Nakamori; Atsushi Nakamura; Masaharu Ohashi; Yusuke Koshikiya (IEICE Trans. Commun., 2025)