Optical transmission line

An optical transmission line including a unitary optical fiber;

• said unitary optical fiber including a section comprising:
• one or more first parts each having, at a predetermined wavelength in a wavelength band in use, a chromatic dispersion with an absolute value of 1 ps/nm/km or more but 10 ps/nm/km or less, and a dispersion slope with a predetermined sign;
• and
• one or more second parts each having, at the predetermined wavelength in said wavelength band in use, a chromatic dispersion, in a sign opposite to that of the chromatic dispersion of each said first part, with an absolute value of 1 ps/nm/km or more but 10 ps/nm/km or less, and a dispersion slope with a sign opposite to that of the dispersion slope of each said first part;
• said first and second parts being arranged adjacent each other along a traveling direction of optical signals in said wavelength band in use in said section of said unitary optical fiber.

An optical transmission line comprising:

• a plurality of first waveguides each having an effective area of 40 μm2 or more at a predetermined wavelength in a wavelength band in use;
• and
• a plurality of second waveguides each having, at the predetermined wavelength in said wavelength band in use, a chromatic dispersion in a sign opposite to that of the chromatic dispersion of each said first waveguide, a dispersion slope in a sign opposite to that of the dispersion slope of each said first waveguide, and an effective area of 40 μm2 or more;
• said optical transmission line including a section in which at least one selected from said first waveguides is arranged so as to be held between two selected from said second waveguides, and at least one selected from said second waveguides is arranged so as to be held between two selected from said first waveguides.

An optical transmission line comprising:

• one or more first waveguides each having, at a predetermined wavelength in a wavelength band in use, a chromatic dispersion with an absolute value of 1 ps/nm/km or more but 10 ps/nm/km or less, and a dispersion slope with a predetermined sign;
• and
• one or more second waveguides each having, at the predetermined wavelength in said wavelength band in use, a chromatic dispersion, in a sign opposite to that of the chromatic dispersion of each said first waveguide, with an absolute value of 1 ps/nm/km or more but 10 ps/nm/km or less and a dispersion slope in a sign opposite to that of the dispersion slope of each said first waveguide;
• said optical transmission line including a section in which said first and second waveguides are arranged adjacent each other along a traveling direction of optical signals in said wavelength band in use,
• wherein each said first waveguide has a positive chromatic dispersion and a positive dispersion slope at the predetermined wavelength in said wavelength band in use, and wherein each said second waveguide has a negative chromatic dispersion and a negative dispersion slope at the predetermined wavelength in said wavelength band in use.

An optical transmission line including a unitary optical fiber;

• said unitary optical fiber including a section comprising:
• one or more first parts each having, at a predetermined wavelength in a wavelength band in use, a chromatic dispersion with an absolute value of 1 ps/nm/km or more but 10 ps/nm/km or less, and a dispersion slope with a predetermined sign;
• and
• one or more second parts each having, at the predetermined wavelength in said wavelength band in use, a chromatic dispersion, in a sign opposite to that of the chromatic dispersion of each said first part, with an absolute value of 1 ps/nm/km or more but 10 ps/nm/km or less, and a dispersion slope with a sign opposite to that of the dispersion slope of each said first part;
• said first and second parts being arranged adjacent each other along a traveling direction of optical signals in said wavelength band in use in said section of said unitary optical fiber,
• wherein each of said first part has a positive chromatic dispersion and a positive dispersion slope at the predetermined wavelength in said wavelength band in use, and wherein each said second part has a negative chromatic dispersion and a negative dispersion slope at the predetermined wavelength in said wavelength band in use.