Abstract: An optical transmission system employs an optical fiber as an optical transmission path that includes a holey fiber and a dispersion-compensating optical fiber. The holey fiber includes a core region that is formed at a center of the holey fiber and a cladding region having a plurality of holes around the core region at regular intervals. The dispersion-compensating optical fiber is connected close to the holey fiber and that collectively compensates wavelength dispersion of the holey fiber at an operation wavelength in at least two wavelength bands out of O band, E band, S band, C band, and L band within a predetermined range depending on a transmission rate.

Abstract: A holey fiber has a core region, a cladding region surrounding the core region, air holes arranged around the core region, and a connection section extending from at least one end portion of the holey fiber. A refractive index of the core region in the connection section is higher than a refractive index of the cladding region without air holes in the connection section.

Abstract: A method of manufacturing a holey fiber includes forming a preform and drawing the preform. The forming includes arranging a core rod at a center of a jacket tube and arranging capillary tubes having hollows around the core rod inside the jacket tube. The drawing includes heat melting the preform in a heating furnace while controlling at least one of a gas pressure to be applied to insides of the hollows of the capillary tubes, a temperature of the heating furnace, and a drawing speed, based on a structure of air holes to be formed in a first layer from the core region.

Abstract: Optical fibers to form an optical transmission line suitable for WDM transmission in a wide-spreading wavelength band, having the following characteristics and parameters: a dispersion in absolute value of 0.5 ps/nm/km to 9 ps/nm/km in a wavelength band of 1430 nm to 1625 nm, a dispersion slope in absolute value of 0.04 ps/nm2/km or less at a wavelength of 1550 nm, a mode field diameter of 7 ?m or less at a wavelength of 1550 nm and a cable cutoff wavelength of less than 1430 nm; core 11 surrounded by cladding 7, core 11 being at least two-layered (first layer 1 at the center and second layer 2 surrounding the first layer; relative refractive index of glass layer ?1 with reference to the cladding being adjusted to not less than 0.6 but not more than 1.6%, relative refractive index of second layer ?2 with reference to the cladding being adjusted to a negative value.

Abstract: Optical fibers to form an optical transmission line suitable for WDM transmission in a wide-spreading wavelength band, having the following characteristics and parameters: a dispersion in absolute value of 0.5 ps/nm/km to 9 ps/nm/km in a wavelength band of 1430 nm to 1625 nm, a dispersion slope in absolute value of 0.04 ps/nm2/km or less at a wavelength of 1550 nm, a mode field diameter of 7 ?m or less at a wavelength of 1550 nm and a cable cutoff wavelength of less than 1430nm; core 11 surrounded by cladding 7, core 11 being at least two-layered (first layer 1 at the center and second layer 2 surrounding the first layer; relative refractive index of glass layer ?1 with reference to the cladding being adjusted to not less than 0.6 but not more than 1.6%, relative refractive index of second layer ?2 with reference to the cladding being adjusted to a negative value.

Abstract: An optical fiber has a zero dispersion wavelength in a wavelength range of 1350 to 1410 nanometers; a dispersion of 2 to 8 ps/nm/km at a wavelength of 1550 nanometers; a dispersion slope of a positive value and not more than 0.05 ps/nm2/km at a wavelength of 1550 nanometers; a transmission loss of not more than 0.4 dB/km at a wavelength of 1380 nanometers; an increase of transmission loss of not more than 0.04 dB/km at a wavelength of 1380 nanometers after a hydrogen aging test; a transmission loss of not more than 0.25 dB/km at a wavelength of 1550 nanometers; and a bending loss of not more than 30 dB/m when the optical fiber is wound at a diameter of 20 millimeters at a wavelength of 1550 nanometers.

Abstract: An optical fiber whose value of a ratio of a dispersion to the dispersion slope ranges between 50 nm and 150 nm at the wavelength of 1590 nm. Also, a dispersion compensated optical fiber includes a depressed layer formed of at least one of a plurality of core layers covering the outer circumference of the center core. The depressed layer has ?0.7% or less of a relative refractive index difference with the clad. The dispersion compensated optical fiber has the ratio of the dispersion to the dispersion slope falling within a range of between 30 nm and 80 nm at the wavelength of 1550 nm, or a dispersion value not larger than ?20 ps/nm/km, a dispersion slope not larger than ?0.05 ps/nm2/km, and an effective core cross sectional area Aeff falling within a range of between 8 and 13 ?m2.

Abstract: An optical fiber comprising a core and a cladding characterized by a dispersion of 0 to 17 ps/nm/km, an effective area (Aeff) of 130 ?m2 or more, a bending loss of 10 dB/m or less in a diameter of 20 mm, a dispersion slope of 0 ps/nm2/km to 0.08 db/nm2/km at a wavelength of 1550 nm, and a cutoff wavelength ?c of a 2 m length of fiber of 1700 nm or shorter, is provided. The optical fiber and an optical transmission system of the present invention are suitable for the WDM transmission.

Abstract: The optical fiber has a dispersion value at a 1.55 ?m-wavelength band, of 6 to 24 ps/nm/km, and satisfies A>3×D+40, where D represents a dispersion value (ps/nm/km) at a central wavelength of a 1.55 ?m-wavelength band, and A represents an effective core area (?m2). The optical transmission line for transmitting an optical signal, which includes the optical fiber is provided as well.

Abstract: A reverse dispersion optical fiber having a small waveform distortion caused by non-linearity wherein an effective core area is made at least 50 ?m2 and a dispersion at a wavelength of the 1.55 ?m band is made not more than ?10 ps/nm/km and a dispersion management optical transmission line having a small waveform distortion obtained by connecting a positive dispersion optical fiber and that reverse dispersion optical fiber in that order along a direction of signal transmission and having a total dispersion of substantially zero.

Abstract: Disclosed is an optical transmission line having a length L of 30 km to 150 km, preferably 30 km to 70 km, an absolute value of a dispersion not smaller than 8 ps/nm/km at a wavelength of 1.55 ?m at every point of the optical transmission line, a maximum accumulated dispersion not larger than 7.5×L (ps/nm) at a wavelength of 1.55 ?m, and a dispersion for the entire optical transmission line of ?5 to +5 ps/nm/km at a wavelength of 1.55 ?m. The optical transmission line is formed by, for example, combination of a positive dispersion optical fiber and a negative dispersion optical fiber.

Abstract: Optical fibers with high non-linearity and low dispersion suitable for the Raman amplification are offered. Their structural and characteristic specifics are as follows: first core 1 with ? profile surrounded with second core 2, further second core surrounded with cladding 5; setting first core 1 for no less than 1.8% of relative refractive index difference from cladding 5; setting second core 2 for no more than ?0.4% of relative refractive index difference from cladding 5, setting ? for 1.5 or larger, making second core 2 at least 2.2 times as large as first core 1 in diameter; and an effective area of no more than 15 ?m2, a dispersion slope of 0.05 ps/nm2/km or lower in absolute value, a dispersion of no less than 5 ps/nm/km and no more than 20 ps/nm/km, in absolute value, a cutoff wavelength of 1350 nm or shorter, and a bending loss of 5.0 dB or lower in a bending diameter of 20 mm, each at a wavelength of 1.55 ?m.

Abstract: An optical transmission line according to the present invention is an optical transmission line which is able to control both the waveform distortion due to the non-linearity phenomenon and the waveform distortion due to dispersion. The optical transmission line is formed by connecting, in series, the first optical fiber (8), of which the dispersion value in the set wavelength band within the 1.5 &mgr;m wavelength band is 6 to 14 ps/nm/km, and the second optical fiber (9), of which the dispersion value in said set wavelength band is −14 to −6 ps/nm/km. The dispersion slopes of the first optical fiber (8) and the second optical fiber (9) are of mutually opposite symbols. Light transmitted from an optical transmitter (11) enters the first optical fiber (8) and light which has been transmitted through the first optical fiber (8) enters the second optical fiber (9). The absolute value of the dispersion in the 1.

Abstract: The present invention resides in an optical fiber able to form an optical transmitting line for wavelength division multiplexing transmission in a wavelength band of 1.5 &mgr;m using a Raman amplifier, and an optical communication system using this optical fiber. The optical fiber has an effective core area from 40 &mgr;m2 to 60 &mgr;m2 in a set wavelength band of at least one portion of a wavelength band of 1.5 &mgr;m; a dispersion value from 4 to 10 ps/nm/km at a wavelength of 1.55 &mgr;m; a dispersion slope set to a positive value equal to or smaller than 0.04 ps/nm2/km in a wavelength band of 1.55 &mgr;m; and a zero dispersion wavelength equal to or smaller than 1.4 &mgr;m. Further, a cutoff wavelength is set to be equal to or smaller than 1.5 &mgr;m at a length of 2 m, and a bending loss is set to be equal to or smaller than 5 dB/m at a diameter of 20 mm in the wavelength band of 1.5 &mgr;m.

Abstract: An optical fiber has a zero dispersion wavelength in a wavelength range of 1350 to 1410 nanometers; a dispersion of 2 to 8 ps/nm/km at a wavelength of 1550 nanometers; a dispersion slope of a positive value and not more than 0.05 ps/nm2/km at a wavelength of 1550 nanometers; a transmission loss of not more than 0.4 dB/km at a wavelength of 1380 nanometers; an increase of transmission loss of not more than 0.04 dB/km at a wavelength of 1380 nanometers after a hydrogen aging test; a transmission loss of not more than 0.25 dB/km at a wavelength of 1550 nanometers; and a bending loss of not more than 30 dB/m when the optical fiber is wound at a diameter of 20 millimeters at a wavelength of 1550 nanometers.

Abstract: An optical transmission line according to the present invention is an optical transmission line which is able to control both the waveform distortion due to the non-linearity phenomenon and the waveform distortion due to dispersion. The optical transmission line is formed by connecting, in series, the first optical fiber (8), of which the dispersion value in the set wavelength band within the 1.5 &mgr;m wavelength band is 6 to 14 ps/nm/km, and the second optical fiber (9), of which the dispersion value in said set wavelength band is −14 to −6 ps/nm/km. The dispersion slopes of the first optical fiber (8) and the second optical fiber (9) are of mutually opposite symbols. Light transmitted from an optical transmitter (11) enters the first optical fiber (8) and light which has been transmitted through the first optical fiber (8) enters the second optical fiber (9). The absolute value of the dispersion in the 1.

Abstract: An optical transmission line configured to control both a waveform distortion due to non-linearity and a waveform distortion due to dispersion. The optical transmission line is formed by connecting in series a first optical fiber to a second optical fiber. The first optical fiber has a dispersion value of 6 to 14 ps/nm/km, and the second optical fiber has a dispersion value of −14 to −6 ps/nm/km, both for a given wavelength band within a 1.5 &mgr;m wavelength band. Further, a dispersion slope of the first optical fiber has an opposite sign to a dispersion value of the second optical fiber. In addition, the first optical fiber is arranged to be closer to an optical signal that inputs the optical transmission line than the second optical fiber.

Abstract: A dispersion management optical transmission system obtained by connecting a positive fiber having a positive dispersion in the 1.5 &mgr;m band and a negative fiber having a negative dispersion, suppressing dispersion in the 1.5 &mgr;m band, suppressing the occurrence of non-linear phenomena, and reducing the transmission loss and an optical transmission line using the same, wherein the dispersion of the positive fiber in the 1.55 &mgr;m band is 8 to 15 ps/nm/km and the dispersion slope is at least 0.04 ps/nm2/km, the dispersion of the negative fiber in the 1.55 &mgr;m band is not more than −40 ps/nm/km and the dispersion slope is not more than −0.08 ps/nm2/km, the cumulative dispersion of the positive fiber is at least 200 ps/nm, and the average dispersion when combining the positive fiber and the negative fiber module is suppressed to any wavelength region of the 1.5 &mgr;m band.

Abstract: An optical fiber comprising a core and cladding characterized by a dispersion of 0 to 17 ps/nm/km, an effective area (Aeff) of 130 &mgr;m2 or more, a bending loss of 10 dB/m or less in a diameter of 20 mm, a dispersion slope of 0 ps/nm2/km to 0.08 ps/nm2/km at a wavelength of 1550 nm, and a cutoff wavelength &lgr; c of a 2 m length of fiber of 1700 nm or shorter, is provided.

Abstract: A dispersion management optical fiber transmission line of a superlow loss formed by combining a plurality of optical fibers and suitable for long distance, high speed, large capacity transmission, that is, an optical fiber transmission line including a positive dispersion optical fiber having a positive dispersion and a positive dispersion slope and a negative dispersion optical fiber having a negative dispersion and negative dispersion slope and having a non-zero dispersion at the 1.55 &mgr;m, wherein the transmission loss at the 1.55 &mgr;m band of the positive dispersion fiber and the negative dispersion fiber are both not more than 0.23 dB/km and the difference in transmission losses of the two optical fibers is not more than 0.05 dB/km.