阅读说明：本技术 光传输系统 (Optical transmission system ) 是由 后藤广树 于 2017-04-28 设计创作，主要内容包括：光传输系统(100)的特征在于,具备：多芯光纤(2001),其具有第1纤芯(2100)及第2纤芯(2200)；以及多个光发送装置(1000)、(1100),它们针对第1纤芯(2100)及第2纤芯(2200),对于同一波长以不同的光功率输出不同种类的调制信号。根据光传输系统(100),在抑制多芯光纤(2001)中的因纤芯间串扰引起的信号的劣化的同时,能够有效利用空闲频带。(An optical transmission system (100) is characterized by comprising: a multicore fiber (2001) having a 1 st core (2100) and a 2 nd core (2200); and a plurality of optical transmission devices (1000, 1100) that output different types of modulation signals at different optical powers for the same wavelength for the 1 st core (2100) and the 2 nd core (2200). According to the optical transmission system (100), it is possible to effectively utilize an idle frequency band while suppressing degradation of a signal due to inter-core crosstalk in the multi-core optical fiber (2001).)

1. An optical transmission system, characterized in that,

the optical transmission system includes:

a multicore optical fiber having a plurality of cores; and

and a plurality of optical transmission devices that output different types of modulation signals at different optical powers for the same wavelength, for 2 adjacent cores that are closest to each other among the plurality of cores.

2. The optical transmission system according to claim 1,

the optical transmission device outputs a wavelength-multiplexed signal including the different types of modulation signals to the 2 cores adjacent to each other with the shortest distance therebetween.

3. The optical transmission system according to claim 2,

the optical transmission device outputs the different types of modulation signals by applying a difference to the optical power according to an optical signal-to-noise ratio.

4. The optical transmission system according to claim 2,

the optical transmission device fixes the transmission characteristic margin of the different type of modulated signal.

5. The optical transmission system according to claim 2,

the optical transmission device alternately arranges the different types of modulated signals in time series, thereby outputting the wavelength-multiplexed signal.

Technical Field

The present invention relates to an optical transmission system for large-capacity optical communication.

Background

With an increase in communication traffic, it is expected that a shortage of transmission capacity will occur in the near future in a backbone transmission system. Conventionally, the transmission capacity has been increased by increasing the number of channels by performing high-density wavelength multiplexing, or the transmission capacity per channel has been increased by increasing the transmission speed or by increasing the modulation signal in multi-valued form.

As a method for further increasing the transmission capacity, attention is being paid to spatial multiplexing of optical signals using a multi-core optical fiber. In the 1-core optical fiber, a plurality of cores are arranged, and different types of optical signals are arranged in each of the plurality of cores and multiplexed, whereby the transmission capacity can be increased in units of core. In the spatial multiplexing system using the multicore fiber, the transmission capacity increases as the number of cores increases, but a plurality of cores need to be arranged close to each other, and there is a problem that an optical signal deteriorates due to crosstalk generated between adjacent cores.

Patent document 1 discloses the following method: the influence of crosstalk generated between adjacent cores is suppressed by inputting signal light having different wavelengths to the most adjacent cores among a plurality of cores arranged in a multicore fiber.

Patent document 2 discloses the following method: the influence of crosstalk generated between adjacent cores is suppressed by reversely transmitting an optical signal to the most adjacent core among a plurality of cores arranged in a multicore fiber.

Disclosure of Invention

Problems to be solved by the invention

However, the method disclosed in patent document 1 requires a spare frequency band in which no signal light is arranged to be set in advance in the signal frequency band to be used, and has a problem of reducing the maximum capacity of the system. In addition, in the method disclosed in patent document 2, since it is necessary to provide a plurality of optical amplifiers and signal combiners in the optical transmission path relay section, there are problems as follows: the number of configurations of the optical transmission system increases, the cost of the entire system increases, and the power consumption of the entire optical transmission system increases.

The present invention has been made in view of the above circumstances, and an object thereof is to obtain an optical transmission system capable of effectively utilizing an idle frequency band while suppressing degradation of a signal due to inter-core crosstalk in multi-core optical fiber transmission.

Means for solving the problems

In order to solve the above problems and achieve the object, the present invention provides an optical transmission system including: a multicore optical fiber having a plurality of cores; and a plurality of optical transmission devices that output different types of modulation signals at different optical powers for the same wavelength, for 2 adjacent cores that are closest to each other among the plurality of cores.

ADVANTAGEOUS EFFECTS OF INVENTION

The optical transmission system of the present invention achieves the following effects: the idle frequency band can be effectively used while suppressing degradation of signals due to inter-core crosstalk in multi-core optical fiber transmission.

Drawings

Fig. 1 is a configuration diagram of an optical transmission system according to embodiment 1 of the present invention.

Fig. 2 is a diagram showing a relationship between modulation signals transmitted through a plurality of cores in a multi-core optical fiber provided in the optical transmission system according to embodiment 1 and frequencies assigned to the modulation signals.

Fig. 3 is a configuration diagram of an optical transmission system according to embodiment 2 of the present invention.

Fig. 4 is a diagram showing an example of spectra of signal light transmitted through a plurality of cores in a multi-core optical fiber provided in the optical transmission system according to embodiment 2.

Detailed Description

Hereinafter, an optical transmission system according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiment.