OPTICAL TRANSMISSION LINE, NEGATIVE DISPERSION OPTICAL FIBER USED FOR THE OPTICAL TRANSMISSION LINE, AND OPTICAL TRANSMISSION SYSTEM COMPRISING OPTICAL TRANSMISSION LINE

摘要

An optical transmission line of low nonlinearity having a small dispersion in the wavelength band (L-band) between 1570 and 1620 nm and enabling wavelength-multiplex optical transmission in the 1520-1620 nm band including the wavelength band conventionally researched. The transmission line is made up of one or more blocks, each constituted by sequentially connecting an optical amplifier (32), an SMF (33) and an L-RDF (34) between an optical transmitter (31) and an optical receiver (35). The SMF (33) has a positive dispersion value and a positive dispersion gradient in the preset wavelength band in the L-band. The L-RDF (34) is a negative dispersion optical fiber of line type for compensating for the dispersion and dispersion gradient in the preset wavelength band of the SMF (33). The SMF (33) and the L-RDF (34) are connected, and the dispersion value in the preset wavelength band over the entire optical transmission line is -1 to 1 ps/nm/km.