PROBLEM TO BE SOLVED: To suppress transmission loss attributable to position accuracy of two optical axes while disposing two optical axes of a transmission path of illumination light to a subject, and a transmission path of the light from the subject in one connector.SOLUTION: A light incident part 54a on which illumination light is incident, and a light emission part 53a for emitting the light from a subject transmitted by a light receiving fiber 11 are provided side by side in one shaft part with a detection light mouth piece 53 of a plug connector 51 as an axis. When the plug connector 51 is connected to a receptacle connector 61, the illumination light is incident on the light incident part 54a of the plug connector 51 from an optical fiber 34 of an illumination light mouth piece 65 of the receptacle connector 61, and the light emitted from the light emission part 53a of the plug connector 51 is received at a light receiving part 64b provided to a detection light mouth piece receiver 64 of the receptacle connector 61, and transmitted to a body device.SELECTED DRAWING: Figure 2【課題】１つのコネクタ内に被検体への照明光の伝送路と被検体からの光の伝送路との２つの光軸を配置しながら、２つの光軸の位置精度に起因する伝送損失を抑制する。【解決手段】プラグコネクタ５１の検出光口金５３を軸とする１つの軸部内に、照明光を入射する光入射部５４ａと、受光用ファイバ１１によって伝送される被検体からの光を出射する光出射部５３ａとを隣接して設ける。プラグコネクタ６１をレセプタクルコネクタ６１に接続したとき、プラグコネクタ５１の光入射部５４ａに、レセプタクルコネクタ６１の照明光口金６５の光ファイバ３４から照明光が入射され、プラグコネクタ５１の光出射部５３ａから出射される光がレセプタクルコネクタ６１の検出光口金受け６４に設けられた受光部６４ｂで受光されて本体装置に伝送される。【選択図】図２
