Optical transmission system, optical transmission path, and photoelectric composite cable

An optical transmission system comprising:

• an optical signal transmitter that outputs an optical signal;
• an optical signal receiver that receives the optical signal;
• and
• an optical transmission path that optically connects the optical signal transmitter and the optical signal receiver and transmits the optical signal, wherein
• the optical transmission path includes:
• a first optical transmission path that has a product of a scattering loss with respect to the optical signal and a length of 6 dB or less and outputs a beam with a beam diameter being enlarged by three times or more when a Gaussian beam emitted from a single-mode optical fiber is input by center excitation;
• and
• a second optical transmission path that is optically connected to the first optical transmission path, is longer than the first optical transmission path, has a transmission loss of 100 dB/km or less with respect to the optical signal, and outputs a beam with a beam diameter being enlarged by less than three times when the Gaussian beam emitted from the single-mode optical fiber is input by the center excitation.

An optical transmission system comprising:

• an optical signal transmitter that outputs an optical signal;
• an optical signal receiver that receives the optical signal;
• and
• an optical transmission path that optically connects the optical signal transmitter and the optical signal receiver and transmits the optical signal,
• wherein
• the optical transmission path has a product of a scattering loss with respect to the optical signal and a length of 6 dB or less and outputs a beam with a beam diameter being enlarged by three times or more when a Gaussian beam is emitted from a single-mode optical fiber and input by center excitation,
• a modulation method of the optical signal is a multi-level modulation method, and
• an error rate of 10-12 or less is realized without using an error correction method.

An optical transmission system comprising:

• an optical signal transmitter that outputs an optical signal;
• an optical signal receiver that receives the optical signal;
• and
• an optical transmission path that optically connects the optical signal transmitter and the optical signal receiver and transmits the optical signal,
• wherein
• in the optical transmission path, a ratio of a minimum value to a maximum value of a beam diameter of a beam to be output is 0.7 or more when a Gaussian beam emitted from a single-mode optical fiber is input with a position of the Gaussian beam being shifted.

An optical transmission system comprising:

• an optical signal transmitter that transmits an optical signal output from a light source;
• an optical signal receiver that receives the optical signal;
• and
• an optical transmission path that optically connects the optical signal transmitter and the optical signal receiver and transmits the optical signal,
• wherein
• the optical transmission path is configured by connecting two or more optical transmission paths,
• the optical transmission paths are connected to each other via an air layer in at least one of connection points, and
• when a Gaussian beam emitted from a single-mode optical fiber is input by center excitation, at least an optical transmission path disposed immediately after the light source among the optical transmission paths to be connected outputs a beam with a beam diameter being enlarged by three times or more, and when the Gaussian beam emitted from the single-mode optical fiber is input with a position of the Gaussian beam being shifted, a ratio of a minimum value to a maximum value of the beam diameter of the beam to be output is 0.7 or more, and a product of a scattering loss with respect to the optical signal and a length is 6 dB or less.