KR20100130835A - A modular apparatus for optical communication - Google Patents

Abstract

PURPOSE: A modular apparatus for optical communication is provided to receive the optical signal branched in the light splitter of OLT(Optical Line Terminator). CONSTITUTION: A light source unit(10) generates and transmits the downward optical signal. A light receiver(30) receives an upward optical signal from an ONU. A reflective beam receiving unit(20) receives the reflection light reflected due to the combination of a spot between the ONU and OLT. A light splitter(100) branches the reflection light. The light splitter transmits the branched reflection light in the reflection light receiver.

Description

Modular Apparatus for Optical Communication

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for optical transmission and reception in an optical communication network, and in particular, an optical fiber branched from an optical distribution unit of an optical module provided in an optical line terminator (OLT) and an optical network terminator (ONU). A call is received to a corresponding optical receiver and a reflected light receiver, and relates to an optical communication apparatus capable of knowing whether an optical signal transmission between an optical communication terminal device and an optical communication terminal device is defective. In addition, the present invention forms a light source unit, a light receiving unit, a reflected light receiving unit, a light distribution unit, a light amount control unit, etc. on a single substrate, thereby applying an integrated optical modularization technology that can monitor the defects in the light transmission state more compactly. An apparatus for optical communication is provided.

 Fiber To The Home (FTTH) based optical subscriber network project aims to provide optical technology based broadband transmission bandwidth by finally laying fiber between individual service subscribers and central base station. To this end, based on the optical technology used in the existing backbone, related technologies such as optical transmission line technology, wavelength division multiplexing technology, optical device technology, optical transmission line distribution technology, etc. are being developed to construct an efficient and economical optical subscriber network. As a result, studies on Ethernet-based passive optical subscriber networks (PONs) have been actively conducted in a single star type subscriber network.

However, in the optical communication, there is a need to monitor the state of the devices located on the line by monitoring the optical signal in order to manage the state of the devices located on the light transmission path.

Conventionally, an optical time domain reflectometer (OTDR) is used as a device for determining the presence or absence of disconnection of an optical transmission path in an optical communication network. In OTDR, the time of the reflected light and the reflected light returned to the incident point of the optical pulse by Rayleigh scattering generated when the optical pulse incident on the incident point of the optical path passes through the optical path and there is a refractive index unevenness such as disconnection. It is a device to identify the position and the state where the refractive index nonuniformity occurred in the optical transmission path by using the characteristic. Rayleigh scattering will be described later.

That is, the OTDR is connected after the optical termination device to detect the failure of optical transmission between the optical communication termination device and the optical communication terminal device.If there is an obstacle in the transmission path while the optical signal is being transmitted, the Rayleigh ( Rayleigh) will cause scattering. By analyzing the reflected light generated by Rayleigh scattering in terms of temporal optical wave shape, the fault position and the fault state are calculated.

However, Ray-ray scattering in an optical communication network may be generated as a failure at one point or several points during the transmission of an optical signal. The method of detecting an obstacle in the optical transmission path by OTDR is to detect the location of the failure in several points. It is difficult to pinpoint accurately and only roughly reveals the location of the fault point and the fault condition.

Therefore, in order to know the defects in the individual elements or the individual optical transmission paths, it is inconvenient to use a separate defect extraction technique and equipment, analysis technique, and equipment, which is undesirable.

The present invention has been proposed to solve the above problems, and the optical signal branched from the optical communication terminal and the optical distribution unit of the optical communication terminal is received by the optical receiver and the reflected light receiver to receive the optical signal between the optical communication terminal and the optical communication terminal device An object of the present invention is to provide an optical communication apparatus capable of knowing whether a transmission defect occurs. In addition, each component applied to the optical communication device is formed on a single substrate and modularized to provide a device for monitoring the light transmission status more simply and accurately.

In order to achieve the above object, the present invention provides an optical communication in which a downlink optical signal is transmitted from an optical communication terminal device (OLT) to an optical communication terminal device (ONU), and an uplink optical signal is transmitted from the optical communication terminal device to the optical communication terminal device. A light source unit generating and transmitting the downlink optical signal; An optical receiver configured to receive the uplink optical signal from the optical communication terminal device; A reflected light receiver configured to receive the reflected light reflected by the downlink optical signal due to a defect at one point between the optical communication terminal device and the optical communication terminal device; And a light distribution unit for splitting the reflected light and transmitting the reflected light to the reflected light receiving unit, wherein the light source unit, the light receiving unit, the reflected light receiving unit, and the light distribution unit are formed on a single substrate and modularized. Provides an optical module.

In another aspect, the present invention is to transmit the downlink optical signal from the optical communication terminal (OLT) to the optical communication terminal device (ONU), and in the optical communication for transmitting an uplink optical signal from the optical communication terminal device to the optical communication terminal device, A light source unit for generating and transmitting; An optical receiver configured to receive the uplink optical signal from the optical communication terminal device; A reflected light receiver configured to receive the reflected light reflected by the downlink optical signal due to a defect at one point between the optical communication terminal device and the optical communication terminal device; A light amount control unit provided to control the light amount of the downlink optical signal generated by the light source unit; And a light distribution unit for branching the incident upstream and / or downstream light signals to be received by the light amount control unit, the light receiving unit and / or the reflected light receiving unit, wherein the light source unit, the light receiving unit, the reflected light receiving unit, the Provided is an optical module of an optical communication terminal device, characterized in that the light quantity control unit and the light distribution unit are formed on a single substrate to form a module.

The light quantity control unit may control the downlink optical signal to be branched from the light distribution unit of the optical communication termination device and transmitted downward with a constant amount of light. That is, the amount of light can be controlled by transmitting the optical signal downward by the desired amount of light through the control in the amount of light control unit. At this time, it is preferable that the light quantity splitter serves to transmit the optical signal from the light distribution unit to the light quantity control unit in order to control the light quantity.

The present invention also provides an optical signal for transmitting a downlink optical signal from an optical communication terminal device (OLT) to an optical communication terminal device (ONU) and transmitting an uplink optical signal from the optical communication terminal device to the optical communication terminal device. A light source unit generating and transmitting the light source; And an optical receiving unit for receiving the downlink optical signal, wherein the light source unit and the optical receiving unit are formed on a single substrate to provide a module of the optical communication terminal device.

On the other hand, in the present invention described above, the light distribution unit is characterized in that the coupler (coupler) for branching the incident optical signal for each direction and / or wavelength, which can be provided in the optical communication terminal device, from the light distribution unit The divided optical signals are received by the optical receiver and / or the reflected optical receiver, which are separately provided, so that it is possible to know whether the optical signal transmission is defective. In addition, the present invention may further include a defect detection unit for detecting the optical signal received by the reflected light receiver to monitor whether the optical signal transmission defect.

The optical communication apparatus to which the modularization technology according to the present invention is applied makes it easier to detect noise or defects occurring in optical elements such as optical transmission paths, connectors, and splitters, and the optical signals branched through the optical distribution units correspond to each other. Received by the optical receiver and / or the reflected light receiver to process the status information of the optical signal in a batch, each optical element is formed modularly on a single substrate can be confirmed and control the optical signal transmission status more compact and accurate .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

My Example 1

1 is a block diagram showing a modular optical communication device according to a first embodiment of the present invention.

First, for convenience of description, the direction of the optical signal sent from the optical module of the optical communication terminal device to the optical module of the optical communication terminal device is defined as a downward direction, and vice versa, it is defined as an upward direction. The optical module of the optical communication terminal device includes a light source unit, a light receiving unit, a reflected light receiving unit and a light distribution unit formed on a single substrate, and the optical module of the optical communication terminal device includes a light source unit and a light receiving unit modularized. In addition, the defect detection unit may be formed together with the substrate in the reflection light receiving unit of the optical module of the optical communication termination device to configure the module.

The light distribution unit is composed of an optical passive element having a function of distributing the optical power propagated along the optical fiber to two or more optical fibers, or conversely, combining the light propagated through the two or more optical fibers into one optical fiber.

The defect detector may be connected to the reflected light receiver to detect the point at which a defect occurs in the optical communication network by analyzing the intensity of the optical signal entering the reflected light receiver.

Referring to FIG. 1, in an optical transceiver of an optical communication network, an optical signal having a wavelength from the light source unit 10 of the optical module 1 of the optical communication termination device emits light and enters the optical distribution unit 100. The optical distribution unit 100 passes the optical signal in the downward direction as it is and transmits the optical signal to the optical receiver 40 provided in the optical module 2 of the optical communication terminal device along the optical transmission path.

Of course, the light source unit 50 of the optical module 2 of the optical communication terminal device can also emit an optical signal in the upward direction. The optical signal in the upward direction is transmitted to the optical receiver 30 provided in the optical module 1 of the optical communication termination device along the optical transmission path. The light source unit 10 may be a laser diode (LD), and the light receiver 30 and the reflected light receiver 20 may be made of a photo diode (PD).

In the transmission of the optical signal in the downward direction, if there is a defect in the optical transmission path, Fresnel reflection occurs. In other words, a part of the light incident on the optical transmission path is reflected back, which is called backscattering. Backscattering is the result of Rayleigh Scattering and Fresnel Reflections. Here, Ray-ray scattering is light scattered inside a high-quality optical transmission path because it is generated by refractive displacement due to density and structural variation inside the optical transmission path, and Fresnel reflection light is different from each other. It is caused by the difference in refractive index when passing through a medium having a refractive index, that is, when there is an air gap in a connection, a splice, a disconnection, and an optical fiber connection in an optical transmission path.

Fresnel reflection causes a large reflection in the form of a pulse, and the reflected light is returned to the optical module 1 side of the optical communication termination device. The reflected light is transmitted upwardly and passes through the light distribution unit 100. The light distribution unit 100 branches the reflected light along the predetermined light path 101 according to the direction and / or wavelength of the light.

The branched reflected light flows along the optical path 101 and is transmitted to the reflected light receiver 30 prepared according to the optical path 101. Therefore, when the optical signal is transmitted to the reflected light receiving unit 30 that receives the reflected light of the optical module 1 of the optical communication terminal device, it can be seen that there is a defect in the optical signal transmission between the optical communication terminal device and the optical communication terminal device. It may be monitored by a detector (not shown). The defect detector may be connected to the reflected light receiver to detect the point at which a defect occurs in the optical communication network by analyzing the intensity and the wavelength of the optical signal entering the reflected light receiver.

In addition, the light distribution unit 100 may serve to branch according to the direction or the wavelength of the optical signal without regard to a name such as an optical wavelength coupler, a wavelength splitter / wavelength combiner (optical splitter / optical combiner), or the like. You just need to be.

Example  2

2 and 3 is a block diagram showing a modular optical communication device according to a second embodiment of the present invention.

First, for convenience of description, the direction of the optical signal sent from the optical module of the optical communication terminal device to the optical module of the optical communication terminal device is defined as a downward direction, and vice versa, it is defined as an upward direction. In this case, the optical module of the optical communication termination device means that the light source unit, the light receiving unit, the reflected light receiving unit, and the light distribution unit are modularized. The optical communication terminal device means that the light source unit, the light receiving unit, and the light distribution unit are modularized. In addition, the light amount controller may be provided together to constitute a module. In addition, the defect detection unit may be formed together with the substrate in the reflected light receiving unit of the optical communication termination device to constitute a module.

First, referring to FIG. 2, in an optical transceiver of an optical communication network, an optical signal having a wavelength from the light source unit 10 of the optical module 1 of the optical communication termination device emits light and enters the optical distribution unit 100. The optical signal passes through the optical distribution unit 100 and is transmitted along the optical transmission path 3 to the optical receiver 40 provided in the optical module 2 of the optical communication terminal device.

The wavelength is received by the optical receiver 40 by the optical distributor 200 provided in the optical module 2 of the optical communication terminal device. The light source unit 50 provided in the optical module 2 of the optical communication terminal device may transmit an optical signal having a wavelength of upward direction, and the wavelength may be transmitted from the optical distribution unit 100 of the optical module 1 of the optical communication terminal device. The optical signal is set to branch separately, and the optical signal is transmitted to the corresponding optical receiver 30.

In the transmission of the optical signal in the downward direction, Fresnel reflection occurs when the optical passive element such as the optical transmission path is defective. It has been described above that this is a form of backscattering. Fresnel reflections are caused by differences in refractive index when light passes through a medium with different refractive indices, ie, when there is an air gap in a connection, splice, disconnection, or fiber optic connection in an optical transmission path. .

Fresnel reflections cause large reflections in the form of pulses, and the reflected light is returned to the optical termination device. The reflected light passes upward and passes through the light distribution unit 100 provided in the optical module 1 of the optical communication termination device. The light distribution unit 100 has a predetermined optical path according to the direction and / or wavelength of the light. Branch the reflected light.

The reflected reflected light flows along the optical path, and the reflected light receiver 20 prepared according to the optical path receives the reflected light. Therefore, when an optical signal is transmitted to the reflected light receiving unit 20 that receives the reflected light of the optical module 1 of the optical communication termination device, it is possible to detect a defect in the optical signal transmission. This can be monitored by a defect detection unit (not shown) provided in the optical module 1 of the optical communication termination device. The defect detection unit is a device that is connected to the reflection light receiver to detect the point at which a defect occurs in the optical communication network by analyzing the intensity, wavelength, etc. of the optical signal entering the reflection light receiver.

Referring to FIG. 3, it can be seen that the light amount controller 60 is provided in the optical module 1 of the optical communication termination device. The light quantity control unit 60 may serve to control the downlink optical signal to be branched from the light distribution unit 100 and transmitted downward with a predetermined amount of light. The amount of light transmission can be controlled by controlling the amount of light to be transmitted downward by the desired amount of light through the control in the light amount controller 60.

Therefore, when there is no defect in the downward transmission of the optical signal, the optical signal of the wavelength is not received by the reflected light receiving unit 20 present in the optical module 1 of the optical communication termination device, so that it is known that there is no abnormality in optical transmission. .

On the contrary, when there is a defect in the downward transmission of the optical signal, the optical signal is received by the reflected light receiving unit 20. Here, the defect detection unit (not shown) may be connected to the reflected light receiver 20 to be formed together on a single substrate, whereby defects in the optical transmission may be monitored. In addition, the light distribution unit 100 may serve to branch an optical signal according to a direction or a wavelength without regard to a name such as an optical wavelength coupler or a wavelength separator / wavelength combiner (optical splitter / optocoupler). . In addition, several couplers and the like may be connected depending on the number of light paths to be branched.

According to the second embodiment of the present invention, the optical distribution unit 200 may be provided in the optical module 2 of the optical communication terminal device, but the optical distribution unit 200 provided in the optical module 2 of the optical communication terminal device may be provided. As a result, it is possible to transmit optical signals of different wavelengths in the upward direction or the downward direction by using one optical transmission path 3.

In addition to the above-described second embodiment, in the optical module 1 of the optical communication terminal device, the light distribution unit 100 is considered in consideration of the number of the light source unit 10 and the number of the light receiving unit 30 and the reflected light receiving unit 20. Of course, the number of the optical distribution device, such as a coupler constituting the can be varied as well as this can be equally applied to the optical module 2 of the optical communication terminal device.

The above embodiments are only intended to illustrate the present invention, and those skilled in the art to which the present invention pertains have various modifications of the above-described embodiments within the scope of the technical idea derived from the matters described in the appended claims. It will be appreciated that modifications and applications are possible.

1 is a block diagram showing a modular optical communication device according to a first embodiment of the present invention,

2 is a block diagram showing a modular optical communication device according to a second embodiment of the present invention;

FIG. 3 is a block diagram illustrating an optical communication apparatus including the light amount controller of FIG. 2.

Claims (10)

In the optical communication for transmitting a downlink optical signal from the optical communication terminal device (OLT) to the optical communication terminal device (ONU), and transmits an uplink optical signal from the optical communication terminal device to the optical communication terminal device, A light source unit generating and transmitting the downlink optical signal; An optical receiver configured to receive the uplink optical signal from the optical communication terminal device; A reflected light receiver configured to receive the reflected light reflected by the downlink optical signal due to a defect at one point between the optical communication terminal device and the optical communication terminal device; And And a light distribution unit for dividing the reflected light and transmitting the reflected light to the reflected light receiving unit, wherein the light source unit, the light receiving unit, the reflected light receiving unit, and the light distribution unit are formed on a single substrate and modularized. Optical module. The method of claim 1, The optical distribution unit is an optical module of an optical communication termination device, characterized in that the coupler (coupler) branching for each direction and / or wavelength of the incident optical signal. The method of claim 1, The substrate further comprises a defect detection unit for detecting whether the reflection of the optical signal transmission by detecting the reflected light received by the reflected light receiver further comprises an optical module of the optical communication termination device. In the optical communication for transmitting a downlink optical signal from the optical communication terminal device (OLT) to the optical communication terminal device (ONU), and transmits an uplink optical signal from the optical communication terminal device to the optical communication terminal device, A light source unit generating and transmitting the downlink optical signal; An optical receiver configured to receive the uplink optical signal from the optical communication terminal device; A reflected light receiver configured to receive the reflected light reflected by the downlink optical signal due to a defect at one point between the optical communication terminal device and the optical communication terminal device; A light amount control unit provided to control the light amount of the downlink optical signal generated by the light source unit; And And a light distribution unit for branching the incident upstream and / or downstream light signals to be received by the light amount control unit, the light receiving unit and / or the reflected light receiving unit, and including the light source unit, the light receiving unit, the reflected light receiving unit, and the light amount. The optical module of the optical communication terminal device, characterized in that the control unit and the optical distribution unit formed on a single substrate (module). The method of claim 4, wherein The substrate further comprises a defect detection unit for detecting whether there is a defect in the transmission of the optical signal by detecting the reflected light received by the reflection light receiving unit optical module of the optical communication termination device. The method of claim 4, wherein The optical distribution unit optical module of the optical communication terminal, characterized in that it comprises at least one coupler (coupler) for branching for each direction and / or wavelength of the incident optical signal. The method of claim 4, wherein And the branching of the downlink optical signal from the light distribution unit to the light quantity control unit is a light quantity splitter. The method according to claim 1 or 4, The light source unit, the light receiving unit, the reflected light receiving unit and the light distribution unit are provided with at least one or more, and the optical communication terminal, characterized in that provided in response to each optical signal in consideration of the optical signal to be split and the generated optical signal Optical module. In the optical communication which transmits the downlink optical signal from the optical communication terminal device (OLT) to the optical communication terminal device (ONU), and transmits the uplink optical signal from the optical communication terminal device to the optical communication terminal device, A light source unit generating and transmitting the uplink optical signal; And And an optical receiving unit for receiving the downlink optical signal, wherein the light source unit and the optical receiving unit are formed on a single substrate to form a module. The method of claim 9, The substrate further comprises an optical splitter for splitting and transmitting the downlink optical signal to the optical receiver.

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