摘要:
A light branching/inserting apparatus which can easily control light signal wavelengths, and which can branch, insert or transmit light signals having an optional wavelength and optional multiplexed number, by using a wavelength selection filter utilizing acousto-optic effects. The apparatus comprises; an ADM node section 10 which has an AOTF 11 with four ports as a wavelength selection filter and is connected to a transmission path, an RF signal generator 20 which generates an RF signal of an optional frequency and applies the signal to the AOTF 11, a selected wavelength-variable light branching section 30 which receives and processes the light signal output from the branching port of the AOTF 11 for each wavelength, a light inserting section 40 which generates an optional number of insertion light signals with optional wavelengths and sends the insertion light signals to an insertion port of the AOTF 11, and a monitoring section 50 which monitors the spectrum of the light signal input/output to/from the ADM node section 10.
摘要:
In an OADM system, an OADM device includes an AOTF. The AOTF can select an optional wavelength by changing the frequency of an RF signal to be applied. An optical signal having a specified wavelength can be dropped from a wavelength-multiplexed optical signal input from an input terminal, or a wavelength-multiplexed optical signal input from an add port can be multiplexed with a through optical signal. However, considering the increase in coherent cross talk, the AOTF should be exclusively used for dropping in an actual device configuration. Otherwise, a drop optical signal is branched by an optical coupler with the wavelength selected by a tributary station. Thus, the wavelength selected by the tributary station can be extracted by the AOTF from the through optical signal.
摘要:
A light branching/inserting apparatus which can easily control light signal wavelengths, and which can branch, insert or transmit light signals having an optional wavelength and optional multiplexed number, by using a wavelength selection filter utilizing acousto-optic effects. The apparatus comprises; an ADM node section 10 which has an AOTF 11 with four ports as a wavelength selection filter and is connected to a transmission path, an RF signal generator 20 which generates an RF signal of an optional frequency and applies the signal to the AOTF 11, a selected wavelength-variable light branching section 30 which receives and processes the light signal output from the branching port of the AOTF 11 for each wavelength, a light inserting section 40 which generates an optional number of insertion light signals with optional wavelengths and sends the insertion light signals to an insertion port of the AOTF 11, and a monitoring section 50 which monitors the spectrum of the light signal input/output to/from the ADM node section 10.
摘要:
In an OADM system, an OADM device includes an AOTF. The AOTF can select an optional wavelength by changing the frequency of an RF signal to be applied. An optical signal having a specified wavelength can be dropped from a wavelength-multiplexed optical signal input from an input terminal, or a wavelength-multiplexed optical signal input from an add port can be multiplexed with a through optical signal. However, considering the increase in coherent cross talk, the AOTF should be exclusively used for dropping in an actual device configuration. Otherwise, a drop optical signal is branched by an optical coupler with the wavelength selected by a tributary station. Thus, the wavelength selected by the tributary station can be extracted by the AOTF from the through optical signal.
摘要:
The invention provides an optical wavelength multiplex transmission method wherein a band in the proximity of a zero dispersion wavelength of an optical fiber is used and optical signals are disposed at efficient channel spacings taking an influence of the band, the wavelength dispersion and the four wave mixing into consideration to realize an optical communication system of an increased capacity which is not influenced by crosstalk by FWM. When optical signals of a plurality of channels having different wavelengths are to be multiplexed and transmitted using an optical fiber, a four wave mixing suppressing guard band of a predetermined bandwidth including the zero-dispersion wavelength &lgr;0 of the optical fiber is set, and signal light waves of the plurality of channels to be multiplexed are arranged on one of the shorter wavelength side and the longer wavelength side outside the guard band.
摘要:
An optical fiber transmission line capable of suppressing the generation efficiency of four wave mixing in transmitting wavelength multiplex signal light. The transmission line employs a single mode optical fiber in which a zero dispersion wavelength is varied in the longitudinal direction of the optical fiber more largely than manufacturing variations in manufacturing conditions of the optical fiber. The use of this optical fiber as the transmission line suppresses the generation efficiency of four wave mixing in transmitting the wavelength multiplex signal light to allow the transmission of the wavelength multiplex signal light with a reduced crosstalk.
摘要:
The invention provides an optical wavelength multiplex transmission method wherein a band in the proximity of a zero dispersion wavelength of an optical fiber is used and optical signals are disposed at efficient channel spacings taking an influence of the band, the wavelength dispersion and the four wave mixing into consideration to realize an optical communication system of an increased capacity which is not influenced by crosstalk by FWM. When optical signals of a plurality of channels having different wavelengths are to be multiplexed and transmitted using an optical fiber, a four wave mixing suppressing guard band of a predetermined bandwidth including the zero-dispersion wavelength &lgr;0 of the optical fiber is set, and signal light waves of the plurality of channels to be multiplexed are arranged on one of the shorter wavelength side and the longer wavelength side outside the guard band.
摘要:
In an optical transmission system for intensively modulating an optical wavelength with a sending signal to be transmitted and optically amplifying a modulated optical signal, a wavelength dispersion characteristic of a single mode optical transmission line can be suitably compensated. The optical transmission system comprises a modulating circuit for modulating optical phases or frequencies of the optical wavelength with the sending signal to set a chirping parameter .alpha. to -0.65 to -1.3, and outputting an modulated signal; an optical transmission line having wavelength residual dispersion value of 16 to 21 ps/nm/Km for transmitting the modulated signal; and a dispersion compensating circuit for compensating wavelength dispersion value, of the optical transmission line, which is set to approximately +500 to +1200 ps/nm when an input optical power is more than -5 dBm.
摘要:
An optical fiber transmission line capable of suppressing the generation efficiency of four wave mixing in transmitting wavelength multiplex signal light. The transmission line employs a single mode optical fiber in which a zero dispersion wavelength is varied in the longitudinal direction of the optical fiber more largely than manufacturing variations in manufacturing conditions of the optical fiber. The use of this optical fiber as the transmission line suppresses the generation efficiency of four wave mixing in transmitting the wavelength multiplex signal light to allow the transmission of the wavelength multiplex signal light with a reduced crosstalk.
摘要:
The invention provides an optical wavelength multiplex transmission method wherein a band in the proximity of a zero dispersion wavelength of an optical fiber is used and optical signals are disposed at efficient channel spacings taking an influence of the band, the wavelength dispersion and the four wave mixing into consideration to realize an optical communication system of an increased capacity which is not influenced by crosstalk by FWM. When optical signals of a plurality of channels having different wavelengths are to be multiplexed and transmitted using an optical fiber, a four wave mixing suppressing guard band of a predetermined bandwidth including the zero-dispersion wavelength λ0 of the optical fiber is set, and signal light waves of the plurality of channels to be multiplexed are arranged on one of the shorter wavelength side and the longer wavelength side outside the guard band.