Optical transmission system

An optical transmission system for optically transmitting information between apparatuses via an optical transmission path, comprising:

• a sending unit that is operable to emit, to the optical transmission path, excitation light for detecting an inter-apparatus connection via the optical transmission path;
• a responding unit that is operable to receive the excitation light from the optical transmission path and emit detection light to the optical transmission path using light energy of the excitation light;
• a response receiving unit that is operable to receive the detection light from the optical transmission path and output a detection light current;
• a detecting unit that is operable to detect a presence or an absence of the inter-apparatus connection based on the detection light current, and generate a detection result;
• an optical transmission light signal transmitting unit that is operable to emit, to the optical transmission path, a light signal for optically transmitting the information based on the detection result by the detecting unit;
• and
• an optical transmission light signal receiving unit that is operable to receive the light signal from the optical transmission path,
• wherein
• the responding unit includes a wavelength conversion element that absorbs at least part of the excitation light and emits the detection light having a peak wavelength being different from a peak wavelength of the excitation light, and
• the response receiving unit includes a filter that blocks the excitation light and allows the detection light, which has the peak wavelength different from the peak wavelength of the excitation light, to pass.