Optical transmission device, optical transmission system, and optical transmission method

An optical transmission system comprising:

• an optical transmission device to be used in the optical transmission system in which a band of an optical fiber transmission path constituted of one optical fiber is shared by a plurality of users by using a wavelength multiplexed signal acquired by wavelength-multiplexing a plurality of optical signals, the optical transmission device comprising:
• an optical monitor configured to output, for each wavelength associated with and allocated to each of the plurality of users, alarm information related to each of the plurality of optical signals;
• a management circuit configured to transmit the alarm information for each wavelength being output from the optical monitor, to only a user with whom the wavelength is associated;
• and
• a multiplexer configured to wavelength-multiplex the plurality of optical signals and output the wavelength-multiplexed optical signals to the optical fiber transmission path, wherein the optical monitor outputs the alarm information of the plurality of optical signals being output from the multiplexer;
• the optical fiber transmission path;
• and
• an optical receiver configured to receive the plurality of optical signals received from the optical fiber transmission path.