Development of Wavelength Converter for Arc Light Detection

Contact loss measurement based on arc light detection makes it possible to estimate the current-collecting performance from catenary lines in electric railways before commercial operation, or after the installation, of new overhead contact systems and new pantographs. This measurement system consists mainly of a photo acceptor, a photo detector and a plastic optical fiber for connecting them. However, the system performance is affected by sunlight because the system detects only visible rays. Therefore, the authors develop a conversion system that can change a broad range of wavelengths—from ultraviolet to visible rays—emitted by the arc light to a voltage signal. The developed measurement system equipped with the wavelength converter can detect ultraviolet rays indirectly. This paper describes the operating principles of the wavelength converter and presents experimental results obtained with the measurement system.