摘要:
Provided are an apparatus and method for tracking a wavelength in a passive optical subscriber network in which a central base station and at least one subscriber terminal are connected via a remote node. The apparatus includes a first wavelength aligning unit multiplexing and aligning wavelengths of optical signals from a plurality of single-mode optical sources of the central base station; a second wavelength aligning unit multiplexing and aligning wavelengths of optical signals transmitted to the remote node from a plurality of single-mode optical sources of the subscriber terminal; and a third wavelength aligning unit demultiplexing and aligning wavelengths of optical signals from the second wavelength aligning unit, the third wavelength aligning unit being included in the central base station. Accordingly, when the wavelengths of passbands of a multiplexer/demultiplexer (MUX/DEMUX) of a remote station change due to a change in the ambient temperature, wavelength tracking is performed by making aligned the wavelengths of optical sources of a central base station, a multiplexer/demultiplexer, and subscriber terminals, thereby minimizing optical channel loss and enabling reliable management of WDM-PON.
摘要:
An optical fiber, and an optical access network, a local area network and optical parts for communication, which uses the optical fiber, are disclosed. The optical fiber whose core diameter is 10 μm˜40 μm has at least two propagation modes in a wavelength over 1200 nm. The optical fiber according to the present invention can reduce packaging costs for optical components, since cross-sectional area of the core is large, compared with the prior art technique adopting a single mode optical fiber, and can transmit ultra-high speed data a relatively long distance, since the mode number and modal dispersion effect of the optical fiber is relatively small, compared with the prior art multimode optical fiber. Also, when using the optical fiber according to the present invention, the optical subscriber network and the local area network can be cost-effectively implemented. In addition, when adopting the optical fiber according to the present invention, productivity of optical components for communication can be improved, costs for an optical component can be reduced and quality of the optical component can be improved.
摘要:
An optical fiber, and an optical access network, a local area network and optical parts for communication, which uses the optical fiber, are disclosed. The optical fiber whose core diameter is 10 μm˜40 μm has at least two propagation modes in a wavelength over 1200 nm. The optical fiber according to the present invention can reduce packaging costs for optical components, since cross-sectional area of the core is large, compared with the prior art technique adopting a single mode optical fiber, and can transmit ultra-high speed data a relatively long distance, since the mode number and modal dispersion effect of the optical fiber is relatively small, compared with the prior art multimode optical fiber. Also, when using the optical fiber according to the present invention, the optical subscriber network and the local area network can be cost-effectively implemented. In addition, when adopting the optical fiber according to the present invention, productivity of optical components for communication can be improved, costs for an optical component can be reduced and quality of the optical component can be improved.
摘要:
A communication recovering system for a wavelength division multiplexed passive optical network (WDM PON) includes a central office and remote nodes. When there is a fault in an optical fiber connecting a first blue/red band coupler to a blue/red band coupler R11, optical signals are inputted/outputted thereto/therefrom through a first 1×2 optical switch and a second blue/red band coupler, and when there is a fault in an optical fiber connecting the second blue/red band coupler to a blue/red band coupler R21, optical signals are inputted/outputted thereto/therefrom through the second 1×2 optical switch and the first blue/red band coupler.
摘要:
A communication recovering system for a wavelength division multiplexed passive optical network (WDM PON). The communication recovering system can recover fault of optical fibers between the central office and the remote nodes without additional optical fibers by grouping two remote nodes and employing an AWG having periodic transmission characteristics, and can also simply and rapidly recover such a fault with minimal optical loss using an AWG of 2×N structure and an On-Off optical switch, although protection optical fibers are additionally installed therein. The system can rapidly recover fault of optical fibers between a local office and optical network units, 1:N manner, using 2×2 optical switches, which are installed to each of the optical network units, a reserved transmitter and receiver, and a transceiver. The communication recovering system has advantages in that it can simplify network structure, be cost-effectively implemented, reduce optical loss, and rapidly perform protection of optical fiber fault.
摘要:
A communication recovering system for a wavelength division multiplexed passive optical network (WDM PON). The communication recovering system can recover fault of optical fibers between the central office and the remote nodes without additional optical fibers by grouping two remote nodes and employing AWGs having periodic transmission characteristics, and can also simply and rapidly recover such a fault with minimal optical loss using 1×N structure of the AWGs and On-Off optical switches, although protection optical fibers are additionally installed therein. The communication recovering system has advantages in that it can simplify network structure, be cost-effectively implemented, reduce optical loss, and rapidly perform protection of optical fiber fault.
摘要:
A fault localization apparatus for an optical line in a wavelength division multiplexed passive optical network is disclosed. The apparatus can detect light loss and fault positions as a channel exhibiting an abnormal receiving state of signals received by each of the upstream receivers is checked, and a monitoring optical signal is used, in which the monitoring optical signal is generated as a pulse is inputted to a light source of the downstream transmitter corresponding to the channel showing such an abnormal receiving state. The apparatus according to the present invention can detect fault positions of optical lines between the central office and the remote nodes and between the remote nodes and the optical network units, since the light source of downstream channel in which faults occur is used as a monitoring light source. The apparatus according to the present invention can be cost-effectively implemented.
摘要:
The present invention provides a method and an apparatus for monitoring optical signal to noise ratio (OSNR) in a wavelength division multiplexing optical transmission system. The present invention utilizes a polarization nulling method and a tunable optical bandpass filter in order to reliably monitor the OSNR by considering a finite polarization nulling ratio, polarization mode dispersion and non-linear birefringence of the optical system in real time measurement of the OSNR. Further, the tunable optical bandpass filter is controlled to filter all wavelength bands of wavelength division multiplexed signals. Since the invention may monitor a plurality of demultiplexed optical signals with a single apparatus, the overall cost of the OSNR monitoring equipment is significantly reduced.
摘要:
This invention relates to a multicast-capable optical cross-connect with layered modularity. Due to its layered modularity, this invention can be applied to many differently structured networks and provides easier maintenance than conventional optical cross-connects and efficient preparation for network evolution or node upgrade. By exploiting its simple elementary switches, multicast-capable optical cross-connect with layered modularity minimizes the switching time. For a given node, M input fiber ports supply multiplexed optical signals from other nodes in the network and m input fiber ports supply multiplexed optical signals generated from the node. M+m 1×M optical power splitters 311, 312, 313, 314, 315 distribute multiplexed input signals. A drop link module 331 selects signals to be dropped at the node where the optical cross-connect is installed. M transmission link modules 321, 322, 323 select signals to be transmitted to other nodes out of input signals.
摘要翻译:本发明涉及具有分层模块化的具有组播能力的光交叉连接。 由于其分层的模块化,本发明可以应用于许多不同结构的网络,并且提供比常规光交叉连接更简单的维护以及用于网络演进或节点升级的有效准备。 通过利用其简单的基本交换机,具有分层模块化的多播能力交叉连接最小化了切换时间。 对于给定节点,M个输入光纤端口提供来自网络中其他节点的复用光信号,并且m个输入光纤端口提供从节点产生的复用光信号。 M + m×1M光功率分配器311,312,313,314,315分配复用输入信号。 下拉链路模块331选择要在其上安装光交叉连接的节点丢弃的信号。 M个传输链路模块321,322,323从输入信号中选择要发送到其他节点的信号。
摘要:
In optical communication systems, an optical signal which is modulated with a data signal is transmitted from an optical transmitter, and is launched into a fiber-optic transmission link. The present invention provides a method and an apparatus for the measurement of the distribution of the reflectivity along an optical transmission line implemented by using the signal processing based on the cross-correlation function between the data signal with which the optical transmitter is modulated and the back-reflected signal returned to the optical transmitter to provide the in-service monitoring of the fiber-optic transmission link.