Optical transmission system and optical transmitter used therein

An optical transmission system in which a transmitter outputs, after amplification, a broadband optical signal, and a plurality of receivers receive the broadband optical signal simultaneously distributed thereto, said transmitter comprising:

• a broadband optical transmitter for outputting a broadband optical signal;
• and
• an optical filter using a predetermined wavelength bandwidth as a basis for passing through said broadband optical signal outputted from said broadband optical transmitter, and passing only a predetermined wavelength bandwidth optical signal which has been passed therethrough, and
• said optical transmission system comprising:
• an optical amplifier for amplifying said predetermined wavelength bandwidth optical signal passed through said optical filter, and outputting the amplified optical signal to said receivers;
• and
• a wavelength router, including a plurality of output ports, for applying wavelength branching to the amplified optical signal based on the wavelength thereof, and outputting branched optical signals from the output ports depending on the wavelengths of the branched optical signals, wherein
• said wavelength router distributes said predetermined wavelength bandwidth optical signal simultaneously to each of the output ports.

An optical transmission system in which a transmitter outputs, after amplification, a broadband optical signal, and a plurality of receivers receive the broadband optical signal simultaneously distributed thereto, said transmitter comprising:

• a first broadband optical transmitter for outputting a first broadband optical signal;
• a first optical filter using a predetermined wavelength bandwidth as a basis for passing through said first broadband optical signal outputted from said first broadband optical transmitter, and passing only a first predetermined wavelength bandwidth optical signal which has been passed therethrough;
• a second broadband optical transmitter for outputting a second broadband optical signal;
• a second optical filter using another predetermined wavelength bandwidth as a basis for passing through said second broadband optical signal outputted from said second broadband optical transmitter, and passing only a second predetermined wavelength bandwidth optical signal which has been passed therethrough;
• and
• a coupler for coupling together said first and second predetermined wavelength bandwidth optical signals passed through, respectively, said first and second optical filters, and
• said optical transmission system comprising:
• an optical amplifier for amplifying said first and second predetermined wavelength bandwidth optical signals coupled by said coupler, and outputting the coupled signal to said receivers;
• and
• a wavelength router, including a plurality of output ports, for applying wavelength branching to the amplified optical signal outputted from said transmitter, and based on a wavelength each uniquely assigned to the output ports, distributes the branched optical signals to the corresponding output ports, wherein
• said wavelength router has a periodic branching characteristic with which the amplified optical signal is branched, separately from said uniquely-assigned wavelengths, based on a periodic wavelength which appears at a periodic interval with respect to each of said uniquely-assigned wavelengths for output to said output ports,
• the wavelength of said first predetermined wavelength bandwidth optical signal passed through said first optical filter includes said periodic wavelengths at least corresponding to said output ports, but does not include said uniquely-assigned wavelengths,
• the wavelength of said second predetermined wavelength bandwidth optical signal passed through said second optical filter at least include said uniquely-assigned wavelengths corresponding to said output ports, but does not include said periodic wavelengths, and
• said wavelength router distributes said first and second predetermined wavelength bandwidth optical signals simultaneously to each of the output ports.

An optical transmitter for transmitting, after amplification, a broadband optical signal, said optical transmitter comprising:

• a broadband optical transmitter for outputting a broadband optical signal;
• an optical filter using a predetermined wavelength bandwidth as a basis for passing through said broadband optical signal outputted from said broadband optical transmitter, and passing only a predetermined wavelength bandwidth optical signal which has been passed therethrough;
• a wavelength multiplexing optical transmitter for outputting a wavelength-multiplexed optical signal to which a plurality of optical signals whose wavelengths are different from the predetermined wavelength bandwidth for transmittance through said optical filter are multiplexed;
• a coupler for coupling said predetermined wavelength bandwidth optical signal passed through said optical filter with said wavelength-multiplexed optical signal outputted from said wavelength multiplexing optical transmitter;
• and
• an optical amplifier for amplifying said predetermined wavelength bandwidth optical signal and said wavelength-multiplexed optical signal coupled by said coupler, and outputting the coupled signal to said receivers.