KR100596407B1 - WDM-PON system with turnable wavelengh by external cavity laser light source - Google Patents

Abstract

The present invention relates to a WDM-PON system based on a wavelength variable external resonant laser light source, the optical transmitter comprising a first variable wavelength waveguide Bragg grating and a first external resonant laser array for generating an optical wavelength for data transmission. And a light receiver comprising an optical detector array, wherein the optical transmitter has a first wavelength multiplexer for multiplexing a plurality of optical wavelengths output from the external resonance laser array, and the optical receiver separates the multiplexed optical wavelengths for each wavelength. An OLT having a first wavelength divider for receiving; The optical receiver for receiving the optical wavelength for data transmission transmitted from the OLT and the wavelength variable second waveguide Bragg grating are formed, and the temperature applied to the waveguide Bragg grid according to the optical wavelength for data transmission input from the OLT is determined. A plurality of ONTs comprising an optical transmitter comprising a second external resonant laser to generate a wavelength variable optical wavelength by adjusting; A second wavelength divider for dividing the multiplexed optical wavelengths transmitted through the optical fiber from the optical transmitter of the OLT for each wavelength and connecting each optical wavelength to a corresponding ONT among the ONTs; And a second wavelength multiplexer for multiplexing a plurality of optical wavelengths output from the optical transmitters of the plurality of ONTs and transmitting the multiple optical wavelengths to the OLT optical receiver through an optical fiber.

Description

WDM-PON system with wavelength variable external resonant laser light source {WDM-PON system with turnable wavelengh by external cavity laser light source}

1 shows a block diagram of a WDM-PON structure for one embodiment of the present invention.

2 illustrates an example of an optical communication path setting process of FIG. 1.

FIG. 3 shows an example of a procedure in which the upward optical wavelength of ONT in FIG. 1 is remotely allocated by the OLT.

4 is a side view of the ONT optical transmission module in the form of surface junction integration based on a PLC.

5 is a side view of the ONT optical transmission module in the form of front junction integration based on a PLC.

6A and 6B are graphs for explaining an ECL operated in a multi mode according to an embodiment of the present invention.

7A and 7B are graphs for explaining an ECL operated in a single mode in another embodiment of the present invention.

8A, 8B and 8C are graphs for explaining the mode hopping phenomenon in the ECL structure.

9A and 9B are graphs for explaining a mechanism of suppressing mode hopping in the case of a single mode operation ECL.

FIG. 10 shows a side view of a single-mode operation ECL as an example of an optical transmission module of ONT based on a silica PLC according to an embodiment of the present invention.

FIG. 11 shows a side view of a single-mode operation ECL as another example of an optical transmission module of ONT based on a silica PLC according to an embodiment of the present invention.

12A and 12B are top views and side-views of multi-mode operation ECL arrays as examples of an optical transmission module (TOSA) of an OLT using a surface bonding technique according to an embodiment of the present invention. Indicates.

13A and 13B are top views and side-views of single-mode operation ECL arrays as another example of an optical transmission module (TOSA) of an OLT using a surface bonding technique according to an embodiment of the present invention. ).

14A and 14B are top views and side-views of multi-mode operation ECL arrays as examples of an optical transmission module (TOSA) of an OLT using a front junction technique according to an embodiment of the present invention. Indicates.

15A and 15B are top views and side-views of single-mode operation ECL arrays as another example of an optical transmission module (TOSA) of an OLT using a front junction technique according to an embodiment of the present invention. ).

16A and 16B illustrate a top view and a side-view of an OLT optical receiving module (ROSA) using a surface bonding technique according to an embodiment of the present invention, respectively.

17A and 17B show side and plan views, respectively, of an example of ONT-ROSA that is wavelength-variable by heat based on a front coupled ECL.

Brief Description of Terms of the Invention

ECL: External Cavity Laser, PLC: Planar Lightwave Circuit,

DCC: Data Control Center, WCC: Wavelength Control Center,

VG: V-groove for passive fiber alignment,

MDF: Main Distribution Frame,

WDM: Wavelength Division Multiplexing,

WDM MUX: WDM Multiplexer (MUX), WDM DMX: WDM De-Multiplexer (DMX),

CO: Central Office, ONT: Optical Network Terminal,

OLT: Optical Line Terminal,

Rx: Receiver (Photo Diode + Electronics),

LD: Laser Diode, PD: Photo Diode,

mPD: monitor PD, WBG: Waveguide Bragg Grating,

ROSA: Receiver Optical Sub-Assembly,

TOSA: Transmission Optical Sub-Assembly,

FTTH: Fiber To the Home, AON: Active Optical Network,

E-PON: Ethernet PON, B-PON: Broadband PON,

G-PON: Gigabit Ethernet PON, UTP: Unshielded Twisted Pair.

The present invention relates to a WDM-PON system, and more particularly, to a hybrid integrated wavelength tunable external resonant laser light source technology that is fundamentally required for WDM-based passive optical subscriber network construction.

Current DSL over UTP and CMTS over HFC technologies are expected to be difficult to provide sufficient bandwidth and quality assurance in providing subscribers with converged voice, data, and broadcast services. In order to solve this problem, FTTH technology for connecting subscribers with optical fibers has been actively studied worldwide.

As the digital home service expands, the average bandwidth of 100 Mbps or more per subscriber is expected. Therefore, the existing DSL and cable modem methods, which cannot provide the same level of bandwidth, are expected to be gradually replaced by the FTTH method. .

The main problems to be solved in the formation of FTTH technology are firstly, a technology that can accommodate the increase in the number of subscribers without significantly increasing the size of the fiber installation, and secondly, the cost of connecting optically to the subscribers. The cost should be lowered to a level comparable to the cost.

The most important point in the development of FTTH technology is to develop a light source suitable for a subscriber network. The characteristics of the subscriber network should be considered to be economical, mass productivity, and easy to install and manage.

Optical subscriber network can be largely divided into PON and AON.

The PON method is being developed in the form of ATM-PON, B-PON, G-PON, E-PON, and the AON method is being developed in the form of connecting an Ethernet switch in a stacked structure by an optical fiber. In the PON and AON systems, an optical transmission path is configured on a single wavelength per transmission direction. However, it is expected that there will be a limit in terms of the use and efficiency of the optical path between the central office and the subscriber station in order to provide the subscriber with a high bandwidth of more than 100 Mbps with guaranteed quality. In order to solve this problem, attempts have recently been made to introduce WDM technology into a subscriber network.

The WDM-PON method increases the number of fiber strands by the number of optical wavelengths by multiplexing a plurality of optical wavelengths on one fiber, thereby reducing the cost of the line by accommodating several subscribers in a single optical path and by intensive operation management at the head-end. Since the cost can be reduced, the first condition to be solved in the formation of the above-described FTTH technology can be satisfied, and the advantages of security and protocol transparency in that the subscriber traffic is separated by fiber channel allocation of different wavelengths for each subscriber are provided. Has

For the WDM-based FTTH network, various schemes for optical signal transmission have been proposed to date. The subscriber has a light source and the subscriber has a modulator instead of a light source, and there is a so-called loop-back method that modulates the light source from CO and sends it back to CO. If there is a light source in the subscriber ONT, the wavelength using a light source with a specified wavelength (for example, DFB-LD) and an optical wavelength locked to the wavelength of external light injected by externally injecting light into a broadband light source such as FP-LD Injection-locking method to generate

에서

)를 출력하는 N개의 광원들과 출력된 광파장들을 다중화하는 하나의 N x 1 WDM MUX(multiplexer)가 설치되고, 수신단에는 수신된 신호를 파장별로 분리하는 하나의 1 x N WDM DMX(demultiplexer)와 광신호로부터 전기적인 신호를 재생하는 N개의 PD(Photo diode, 광 검출기)가 설치된다. 그러나, 이와 같은 방식이 갖는 단점은 가입자에게 서로 다른 파장이 지정된 ONT를 생산, 관리 그리고 설치해야 하는 이른바 물품관리(inventory management)문제가 발생한다는 점이다. 즉, 가입자에 광파장이 지정된 광원이 장착되는 방식이 대량으로 시장에 적용될 경우 물품관리 문제는 시장 확장에 큰 걸림돌이 될 수 있다. If the subscriber is equipped with a light source for which light wavelength is designated, light sources for transmitting different light wavelengths to subscribers included in the unit network should be assigned. In this case, the transmitting end has an optical signal of different wavelength (

in

1 N x 1 WDM MUX (multiplexer) for multiplexing the output light wavelengths and N light sources for N PDs (photo diodes) are provided for reproducing electrical signals from the optical signals. However, the drawback of this approach is that subscribers encounter so-called inventory management problems that require the production, management and installation of ONTs with different wavelengths. In other words, if the subscriber is equipped with a light source that is assigned a light wavelength is applied to the market in large quantities, the problem of goods management can be a big obstacle to market expansion.

One way to solve these goods management problems is to provide subscribers with light at the wavelength specified by the CO. Various schemes have been proposed for this class, one of which sends an incoherent broadband light source (e.g. EDFA) down to the subscriber, splits the wavelength by the WDM DMX near the subscriber and injects it into the subscriber's FP-LD. It is a data direct modulation method that transmits upward after injection-locking one mode of FP-LD.

However, the disadvantages of this method are firstly, considering the optical power of the external injection light, an expensive EDFA should be used as the broadband light source. Second, data transmission of 1 Gbps or more due to instability and optical interference noise caused by the temperature variation of injection-locking. It is difficult to do.

Another way to solve the goods management problem is to lock the mode of the FP-LD by placing the DFB-LD in CO and its output light source to the FP-LD of the subscriber.

However, the disadvantage of this method is that the locking state is very easily broken because the wavelength of the DFB-LD in the CO and the wavelengths of the FP-LD modes of the subscriber are high.

Meanwhile, in order to solve the volume problem of the optical transmission / reception module generated by CO accommodating a plurality of subscribers based on the WDM-PON, the development of an array-type multi-wavelength light source module is actively progressing with various light source methods. . Conventionally, most of them are based on the DFB-LD type, but there are still many problems to improve such as the complexity of the manufacturing process, the decrease in yield due to the increase in the number of wavelengths, and the reliability of the stable operation.

As such, the important problems to be solved by the WDM-PON are to achieve a low cost of the first optical module, a high integration of the OLT optical module, and a third ONT independent of the optical wavelength.

The technical problem to be achieved by the present invention is to enable a low cost of the optical module through easy mass production by using a manual sorting method based on the PLC in the packaging process that takes up a large portion of the current optical module price. to provide.

In addition, in order to accommodate CO of tens of thousands to more than 100,000 subscribers, the volume of OLT optical modules is increased to reduce the volume. To this end, the present invention provides a method of implementing multi-wavelength optical transmission and wavelength multiplexing functions on the same chip, and a method of implementing wavelength demultiplexing and multi-wavelength optical signal reception functions on the same chip.

In addition, it solves the problem of mass production and manageability, which is a disadvantage of ONT equipped with a light source with a specified wavelength, and at the same time, the optical power budget of the loop-back optical subscriber network without the light source in ONT, And we want to solve the shortcomings of the operation reliability aspect of ONT. To this end, ONT provides a way to include a light source but not specify a particular light wavelength. It is to solve the so-called management problem in which ONT is distinguished by optical wavelength by giving a wide band wavelength variable capability that can vary the entire optical wavelength band used for PLC-ECL mounted in ONT. That is, the wavelength of the ONT light source can be set by the installer when the ONT is installed in the subscriber zone, or the WBG temperature of the ONT optical transmission module can be set by the optical wavelength control signal sent from the OLT to the ONT. . Therefore, since ONT is not assigned a specific light wavelength at the time of production, but is set after manual or automatic installation, it solves a management problem.

In the WDM-PON system based on the wavelength variable external resonant laser light source according to the present invention for achieving the above technical problem, the wavelength variable first waveguide Bragg grating (WBG) is formed and generates a first wavelength for data transmission A first wavelength multiplexer comprising an optical transmitter comprising an external resonance laser (ECL) array and an optical receiver comprising an optical detector (PD) array, wherein the optical transmitter multiplexes a plurality of optical wavelengths output from the first external resonance laser array. An optical line terminal (OLT) having a first wavelength divider (WDM DMX) for receiving the multiplexed optical wavelengths separated by wavelength; A light receiving unit for receiving the data wavelength for transmitting data transmitted from the OLT and a wavelength variable second waveguide Bragg grating (WBG) are formed and the second waveguide Bra grating according to the light wavelength for data transmission input from the OLT. A plurality of optical network terminals (ONTs) comprising an optical transmitter configured of a second external resonant laser (ECL) to control the temperature applied to the optical wave; A second channel located in a main distribution frame (MDF) near the plurality of ONTs and dividing the multiplexed optical wavelengths transmitted through the optical fiber from the first wavelength multiplexer of the OLT by wavelength to connect each optical wavelength to a corresponding ONT among the ONTs; Wavelength divider (WDM DMX); And a second wavelength multiplexer located in a main distribution frame (MDF) near the plurality of ONTs and multiplexing a plurality of optical wavelengths output from the optical transmitters of the plurality of ONTs and transmitting the multiplexed optical wavelengths to a first wavelength divider of the OLT through an optical fiber. WDM MUX).

In addition, in the wavelength division multiplexing passive optical subscriber network (WDM-PON) system based on the wavelength variable external resonant laser light source according to the present invention for achieving the above technical problem, a waveguide bra in a flat waveguide circuit (PLC) An optical transmitter comprising an external resonance laser (ECL) array for forming a grid (WBG) to generate an optical wavelength for data transmission that can be varied; A wavelength multiplexer (WDM MUX) for multiplexing a plurality of optical wavelengths output from an external resonance laser (ECL) array of the optical transmitter; A wavelength divider (WDM DMX) for separating and distributing the multiplexed optical wavelengths inputted from an optical network terminal (ONT) for each wavelength; And an optical line terminal (OLT) based on a tunable external resonant laser light source including a light receiving unit comprising a photodetector (PD) array for detecting an optical wavelength distributed from the wavelength divider (WDM DMX).

In addition, the WDM-PON wavelength division multiplex passive optical subscriber network system based on the wavelength variable external resonant laser light source according to the present invention for achieving the above technical problem is to receive an electrical signal transmitted from the optical line terminal (OLT) A light receiving unit (Rx) to convert to; A data control center (DCC) for separating general data and WBG control data from information converted into an electrical signal from the optical receiver; A WCC (wavelength control center) for receiving an input of the WBG control data from the DCC and controlling an uplink optical wavelength for uplink data transmission by adjusting a temperature of a waveguide brogg grid (WBG) according to the WBG control data; And an optical network terminal (ONT) based on a wavelength-variable external resonant laser light source including an external resonant laser (ECL) for modulating uplink data to the uplink optical wavelength and transmitting it to the optical termination device (OLT).

In addition, in the wavelength division multiplex passive optical subscriber network (WDM-PON) system according to the present invention for achieving the above technical problem, the optical wavelength control method of the optical network terminal (ONT), the wavelength division multiplex passive optical subscriber network ( A method of controlling uplink optical wavelength of an optical network terminal (ONT) in a WDM-PON system, the method comprising: (a) determining uplink optical wavelength information of the ONT corresponding to a predetermined downlink wavelength of the ONT newly connected to a network; ; (b) the OLT loading the uplink optical wavelength information determined in the step (a) to the downlink optical wavelength determined in the ONT and transmitting the information to the ONT; (c) the ONT generating an upward optical wavelength through the upward optical wavelength information transmitted by being loaded on the downward optical wavelength from the OLT in the step (b); And (d) the ONT includes transmitting uplink data to the OLT by loading uplink data on the uplink optical wavelength generated in step (c).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a block diagram of a WDM-PON structure for one embodiment of the present invention.

Referring to FIG. 1, the WDM-PON network structure includes an optical line terminal (OLT) 100 corresponding to a CO (Centrol Office, hereinafter referred to as 'CO') and an subscriber optical terminator (ONT) corresponding to a subscriber ( The optical network terminal (hereinafter referred to as 'ONT') 160 has a PON form without active elements.

The OLT 100, located in the Central Office (CO), has a number of external cavity laser (ECL) arrays 112 with planar lightwave circuit (PLC) 110 platforms. Multi-channel optical transmission module integrated in a hybrid form to transmit light of different wavelengths, and a plurality of PDs (photo-diodes, hereinafter referred to as 'PD') for receiving input light of different optical wavelengths. The array 122 includes a multi-channel optical reception module integrated in a hybrid form on the PLC 120 platform.

ONT 160 is composed of a wavelength variable ECL that can arbitrarily adjust the light wavelength.

1 illustrates a method of eliminating the light wavelength division of the ONT 160 while mounting a light source in the ONT 160. The optical transmission module of the ONT 160 takes the form of an ECL consisting of FP-LD and WBG, and the center wavelength of the WBG reflection band is set to a desired wavelength by the thermo-optic effect. The optical wavelength setting for transmitting uplink data of the ONT 160 is a method of manually setting a wavelength specified by the installer when installed in the subscriber's premises, and after the ONT is installed in the subscriber's premises, the OLT transmits wavelength information through the optical wavelength allocated to the subscriber. By using the method to set the ONT 160 itself assigned wavelength.

In FIG. 1, PLC-based ECL (PLC-ECL) is adopted as a light source module in constructing the WDM-PON, and the center wavelength of the light emitted from the PLC-ECL for ONT can be varied in the entire wavelength band for optical communication. On the other hand, the center wavelength of the light oscillated by OLT PLC-ECL is slightly variable from side to side with respect to the center wavelength set at the time of manufacture so as to match the wavelength of optical communication determined by ITU-T, and modulates data directly to PLC-ECL And each of the multi-channel optical transmission and optical reception modules of the OLT 100 includes a WDM multiplexer (MUX) and a demultiplexer (DMX) integrated on a single chip.

Here, the characteristics of the wavelength variable PLC-ECL 112 (170) optical transmission module is as follows.

A Fabry-Perot laser diode (FP-LD) is butt mount or surface mount on the PLC and the Waveguide Bragg at any point on the optical waveguide between the V-groove and the FP-LD to which the fiber is attached. -grating (WBG) is molded. The output light wavelength of PLC-ECL is one or more longitudinal mode (s) included in the WBG reflection band among the light wavelengths satisfying the phase condition determined by the external cavity distance formed between FP-LD and WBG. Is determined.

Therefore, if the temperature of the WBG is locally changed, the effective refractive index of the PLC waveguide is changed, so that the output light wavelength of the PLC-ECL 112 (170) can be varied.

Downlink optical signal distribution is performed manually at the WDM DMX 140 near the ONT 160. All the optical transmission module 110 and the optical reception module 120 is based on the PLC for the minimization and mass production of the packaging (packaging).

The OLT optical transmission module 110 has an array of external cavity lasers (ECLs) 112-1, 112-2, and 112-n composed of FP-LD and waveguide bragg grating (WBG). Is arranged. Each ECL 112 is assigned a reflection center wavelength of the corresponding WBG to have a wavelength near the wavelength recommended by the ITU-T, and finely varies the temperature of the WBG so that the output light wavelength matches the recommended wavelength of the ITU-T. . The output end of each ECL 112 is input to the WDM MUX 114 formed on the same chip, and the wavelength multiplexed optical signal is output at the output of the WDM MUX 114. As such, the ECL array 112 and the WDM MUX 114 form a PLC on the same chip, thereby simplifying the final output fiber pigtailing in one process.

In the optical transmission module mounted in the OLT, a plurality of PLC-ECL arrays are integrated with an N × 1 WDM MUX 114 on a single wafer, and a plurality of light sources are combined into one output terminal. At the output of the WDM MUX 114, a V-groove (VG) 116 is positioned to connect one strand of optical fiber. On the other hand, in the optical reception module 120 mounted on the OLT 100, a V-groove (VG) 126 is positioned to introduce a strand of optical fiber on a single chip, and the 1 x N WDM DMX 124 connected thereto is located. The light receiving PD 122 is arranged in an array form at each of the N WDM DMX 124 output ports.

The biggest feature of the optical transmitting module 110 and the optical receiving module 120 of the OLT 100 uses a manual alignment method, and the output of the optical transmitting module 110 and the optical receiving module 120 has one port. The fiber pigtail is simple because it is unified with. The simplicity of fiber pigtails can significantly reduce packaging costs, increase yield and improve module reliability. In addition, since the multi-channel optical transmission module 100 and the multi-channel optical reception module 120 are integrated on a single chip, it is possible to solve the volume problem due to the mass installation of the optical module.

In the optical reception module 120 of the OLT, a WDM DMX 124 is positioned at an input terminal of a chip, and a PD 122 is connected to each output terminal of the WDM DMX 124. Like the OLT optical transmission module 110, the WDM DMX 124 and PD array 122 are integrated on a single chip.

The optical wavelength multiplexed optical signal output from the optical transmission module 110 of the OLT 100 is a WDM De-Multiplexer (WDM DMX) of a main distribution frame (MDF) located near a subscriber's residence. The wavelength is separated and each optical wavelength is transmitted to the corresponding ONT 160.

The optical signal transmitted from the WDM DMX 140 is converted into an electrical signal at an Rx (optical reception module) (hereinafter referred to as 'Rx') 162 of the ONT 160 to be referred to as a DCC (data control center). 164).

In the DCC 164, the general data and the WBG control data are separated from the data input from the optical transmission module 110 of the OLT 100, and the general data is sent to the downlink data processor 180, and the WBG control information is WCC (wavelength). control center, hereinafter referred to as 'WCC'). The WCC 166 loads the wavelength value through the WBG control data input from the DCC 164 and applies a corresponding temperature to the WBG of the PLC-ECL 170.

The output of the mPD fed back from the PLC-ECL 170 to the WCC 166 is used to monitor the optical output of the ECL resonant mode, as well as fine-tuning the WBG reflected center wavelength based on the wavelength assigned from the OLT 100. This can be used to find the maximum point of the ECL optical power. This wavelength adjustment function may also be used to optimize the optical wavelength of the ECL 170 of the ONT 160 to maximize the optical power received by the OLT 100.

In such a case, when information on the optical reception sensitivity received from the optical transmission module 110 of the OLT 100 is separated from the data in the DCC 164 and transmitted to the WCC 166, the WCC 166 analyzes the previous record. By adjusting the temperature of the PLC-ECL (170) WBG to adjust the output light wavelength.

2 illustrates an example of an optical communication path setting process of FIG. 1.

Referring to FIG. 2, the downward light wavelength of the ONT 200 is the ONT 200 (ONT1 201, ONT2 202, ONT3 203, ONT4 204, ONT5 205, ONT6 206 in FIG. 2). And an output port of the WDM DMX 140 near ONT 200 connected to the corresponding input of ONT7 207, and so on, and thus the physically defined downward light wavelength for each of the ONTs 200. The information is stored in the OLT 100 as network setting information.

Similarly, the upward optical wavelength is also determined by the input port of the WDM MUX 150 near the ONT 200 connected to the corresponding output terminal of the ONT 200, which is also stored in the OLT 100 as network setting information.

2 illustrates a case where the WDM MUX 150 and the WDM DMX 140 located near the ONT 200 are connected to the respective ONTs 200 in the same order, and the uplink wavelength and the downlink wavelength for each ONT 200 are illustrated. This is the same case. Reference numeral 210 in FIG. 2 denotes fixed wavelengths connected by an output port of the WDM DMX 140. Reference numeral 220 in FIG. 2 indicates wavelengths allocated by the PLC-ECL 170.

FIG. 3 illustrates an example of a procedure in which the upward light wavelength of the ONT 160 in FIG. 1 is remotely allocated by the OLT 100.

Referring to FIG. 3, after the installation of the ONT 160 is completed, the OLT 100 determines uplink optical wavelength information of the corresponding ONT 160 through the downlink optical wavelength determined by the corresponding ONT 160 (S300).

The OLT 100 transmits uplink wavelength information determined through the downlink wavelength determined by the ONT 160 to the corresponding ONT 160 (S310).

When the corresponding ONT 160 obtains the uplink wavelength information from the OLT 100 through the downlink wavelength, the corresponding ONT 160 sets up the wavelength for the uplink wavelength through the information (S320).

In detail, the setup process transmits uplink wavelength information to the WCC 166, and the WCC 166 supplies a constant current to the wavelength control portion of the PLC-ECL 170 to be tuned to the designated uplink wavelength.

When the initialization (initialization) process is completed, afterwards the uplink data is loaded on the optical wavelength to the OLT 100 (S330).

4 is a side view of the ONT optical transmission module in the form of surface junction integration based on a PLC.

Referring to FIG. 4, a semiconductor chip 420 couples an active region 424 that generates light and a generated light to a PLC waveguide 440 in the PLC. Passive waveguide region (passive region) 422. As such, the semiconductor chip 420 is mounted to a PLC using surface mount integration techniques.

InP-based semiconductor materials are used for the active waveguide region 424 of the semiconductor chip 420, and polymers, nitrides, and the like are used for the passive waveguide region 422.

The semiconductor chip waveguide 426 and the PLC waveguide 440 are surface bonded in the coupling region 445.

A WBG 455 is formed on the PLC waveguide 440. A heater 450 electrode is attached to the WBG 455 to control the temperature of the WBG 455, thereby forming a wavelength variable WBG 455. Done. The PLC waveguide 440 adjacent to the optical fiber 470 is a spot-size converter in which a beam in the PLC waveguide 440 is enlarged in order to increase the optical coupling efficiency with the optical fiber 470. 460 has a structure. The optical fiber 470 may be manually aligned and mounted on the PLC using the V-groove 475 to simplify the alignment process.

The PLC has a WBG 455 whose reflection band is varied by a thermo-optic effect, and the wavelength of the light oscillated through the optical fiber is externally generated by the backside of the semiconductor chip 420 and the WBG 455. Is determined by

When silica is used as the material of the PLC waveguide 440, the WBG wavelength variable range due to the thermo-optic effect is only about 10 nm, so the number of channels is too small to be used for WDM (for example, at 200 GHz intervals. Channel) Poor economic utility. In contrast, the WBG 455 using a polymer material can tune the oscillation wavelength in the entire C-band region having a wavelength variable range of 30 nm and a communication wavelength region (for example, 18 channels at 200 GHz interval). In addition, the wavelength range of the WBG using the PLC waveguide 440 of the silica / polymer hybrid type is about 10 ~ 15 nm.

The basic theory is related as follows.

는 수학식 1과 같다.Bragg Wavelength Reflected from WBG

Is the same as Equation 1.

는 PLC 도파로(440)의 유효굴절율,

는 코어 내에 입사광이 만나는 WBG의 격자주기이다.here,

Is the effective refractive index of the PLC waveguide 440,

Is the lattice period of the WBG where incident light meets in the core.

는 다음 수학식 2로 결정되며, 이는 전체 격자길이에 반비례하므로 격자와 빛의 상호작용 길이가 길수록 대역폭은 작아지게 된다.3 dB bandwidth of reflected wavelength

Is determined by Equation 2, which is inversely proportional to the total grid length, so that the longer the length of the grid-light interaction, the smaller the bandwidth.

Where L is the interaction length between light and the grating and m is the number of gratings.

에 대하여,

, L을 정한다. 반사되는 브래그 파장 주위에 발생하는 부엽파(side lobe)를 줄이기 위해서 격자 깊이를 Gaussian 형태의 apodization를 취할 수 있다.The reflectance R when the phase conditions of the incident wave and the reflected wave are completely satisfied is determined by the coupling coefficient k and the coupling length L of the two waves. To obtain the desired Bragg wavelength, the effective refractive index given

about,

, L is determined. To reduce the side lobe that occurs around the reflected Bragg wavelength, Gaussian-shaped apodization can be taken for the grating depth.

On the other hand, the wavelength tunable characteristics of the WBG is given by Equation 3 in relation to the applied thermal power and the transition wavelength.

는 열광학계수이다. Where m is the Bragg diffraction order,

Is the thermo-optic coefficient.

nm로 주어지며, 30nm 파장 가변을 위해서는 약 15 ^oK 정도의 온도변화가 요구된다. PLC에 silica 물질을 사용하는 경우 열광학계수는 대략 1x10^-5 [K^-1]이고, 폴리머 물질의 경우는 1.5x10^-4 [K^-1]이다. 따라서, 같은 온도 변화를 인가한 경우일지라도 폴리머 물질을 사용한 WBG이 반사 대역의 중심파장 변이가 실리카의 경우에 비하여 약 15배 크다.When the thermo ^- optic coefficient is 2x10 ^-3 [K ^-1 ], L = 0.5um, m = 1,

Given in nm, a change in temperature of about 15 ^o K is required for a 30 nm wavelength change. When silica material is used for PLC, the thermo-optic coefficient is approximately 1x10 ^-5 [K ^-1 ], and for polymer material it is 1.5x10 ^-4 [K ^-1 ]. Therefore, even when the same temperature change is applied, the center wavelength variation of the reflection band of the WBG using the polymer material is about 15 times larger than that of the silica.

On the other hand, if you introduce the characteristics of the tunable polymer WBG that has been manufactured (Han Sun-gyu, Final Report of 'Development of plastic waveguide tunable wavelength filter module', ICT Industry Development Project, Ministry of Information and Communication, April 30, 2001)

= -0.3 nm/^oc (온도 변화에 따른 중심 광파장 변화율)

= -0.3 nm / ^o c (central light wavelength change rate with temperature)

= -2 x 10^-4/^oc (온도 변화에 따른 굴절율 변화율)

= -2 x 10 ^-4 / ^o c (refractive index change rate with temperature change)

Tunable Range: 1535-1560 nm (25 nm tuning)

Applied voltage for 25nm wavelength tuning: equal to 50 mV.

This example shows that the technical features of the present invention are feasible.

5 is a side view of the ONT optical transmission module in the form of front junction integration based on a PLC.

Referring to FIG. 5, the basic configuration is the same as that of FIG. 4, except that the configuration of the semiconductor chip 520 used and the front junction optical coupling method of the PLC waveguide 540 are used. The passive waveguide region 522 of the semiconductor chip 520 increases the size of the light beam generated in the active waveguide region 524 to improve the optical coupling efficiency. In general, the far-field angle is measured as an index for expanding the size of the light beam, and the far-field angle in the vertical / horizontal direction is preferably set to 15 degrees or less. A portion not described in FIG. 5 will be referred to FIG. 4.

6A and 6B are graphs for explaining an ECL operated in a multi mode according to an embodiment of the present invention.

6A and 6B, the size of the FWHM of the reflection band of the WBG is large enough to include a plurality of ECL cavity modes, and at the same time smaller than the designated WDM channel (wavelength) spacing.

6A and 6B, the WDM channel spacing is 200 GHz, and the FWHM of the reflection band of the WBG is 0.8 nm. As described above, the ECL operated in the multi-mode has a disadvantage in that the WDM channel wavelength spacing needs to be wider than the ECL operated in the single mode. There is an advantage that can be reduced to the negligible effect of mode hopping.

7A and 7B are graphs for explaining an ECL operated in a single mode in another embodiment of the present invention.

7A and 7B, it can be seen that the oscillation power difference between the main mode and the adjacent mode can be increased by reducing the bandwidth of the WBG mode so that only one ECL cavity mode is resonant. That is, the oscillation mode can be made into a single mode by increasing the side-mode suppression ratio (SMSR).

8A, 8B, and 8C show that the oscillation mode transitions to the adjacent mode when the ECL cavity mode transitions to the short wavelength according to the temperature, assuming that the center wavelength of the WBG reflection band is independent of temperature.

In the transition process, when the optical output power between two adjacent ECL cavity modes is similarly formed, as shown in FIG. 8B, the mode transition phenomenon impairs the L-I characteristics and causes an error in data transmission during direct modulation of the light source.

8A, 8B and 8C are graphs for explaining the mode hopping phenomenon in the ECL structure.

이고, WBG의 물질이 silica인 경우 WBG 반사대역 중심파장 변화는 대략

이다. 8A, 8B, and 8C, the WBG reflection bandwidth can be reduced to oscillate only one specific ECL cavity mode as shown in FIG. 8A. In this case, there is an advantage of outputting in a single mode, but when the temperature and current changes in the cavity occurs, the oscillating cavity mode transitions to the adjacent mode. The wavelength shift with temperature in the ECL cavity mode is design dependent but

If the material of WBG is silica, WBG reflection band center wavelength change is about

to be.

8A, 8B, and 8C show that the oscillation mode transitions to the adjacent mode when the ECL cavity mode transitions to the short wavelength according to the temperature, assuming that the center wavelength of the WBG reflection band is independent of temperature.

In the transition process, when the optical output power between two adjacent ECL cavity modes is similarly formed, as shown in FIG. 8B, the mode transition phenomenon impairs the L-I characteristics and causes an error in data transmission during direct modulation of the light source.

9A and 9B are graphs for explaining a mechanism for suppressing mode hopping in the case of a single mode operation ECL.

9A and 9B, a graph illustrating a case where a phase control section is inserted into an external cavity formed in an ECL is illustrated. In general, as the bias current increases in the semiconductor active region generating light, the wavelength of the ECL cavity mode moves to the long wavelength region as shown in the direction B of FIG. 9A. This wavelength shift can be compensated by adjusting the current flowing in the phase control section. This concept is explained as follows.

는 LD bias 전류이고,

는 phase control section의 DC 전류 성분이고,

는 LD bias 전류의 변화량이다. 또한,

는

에 의한 ECL cavity mode 장파장 천이를 보상할 수 있는 phase control section에 주입해 주어야 하는 전류량을

로 나누어 준 값으로서 phase control section의 파장천이보상 효율성을 나타낸다. here,

Is the LD bias current,

Is the DC current component of the phase control section,

Is the amount of change in LD bias current. Also,

Is

The amount of current to be injected into the phase control section to compensate for the long wavelength transition by the ECL cavity mode.

This value is divided by to represent the wavelength shift compensation efficiency of the phase control section.

값은 phase control section에서 사용되는 도파로 물질의 열광학(Thermooptic) 계수 또는 전계광학(Electrooptic) 계수 부호에 의하여 결정된다. 예를 들어, 폴리머의 경우는 열광학계수가 음수이므로

값은 양수가 되고, 한편 silica 물질의 경우는 열광학계수가 양수이므로

값은 음수가 된다.

The value is determined by the thermooptic or electrooptic coefficient sign of the waveguide material used in the phase control section. For example, the polymer has a negative thermo-optic coefficient

The value is positive, whereas for silica materials the thermo-optic coefficient is positive

The value is negative.

FIG. 10 shows a side view of a single-mode operation ECL as an example of an optical transmission module of ONT based on a silica PLC according to an embodiment of the present invention.

Referring to FIG. 10, most of the structural diagrams of the PLC-ECL whose wavelength is thermally changed by the surface bonding technique of FIG. 4 are the same. 4, a phase control section 1080 using thermo-optic or electro-optic effects is inserted for the stability of the ECL oscillation mode. A portion not described in FIG. 10 will be referred to FIG. 4.

FIG. 11 shows a side view of a single-mode operation ECL as another example of an optical transmission module of ONT based on a silica PLC according to an embodiment of the present invention.

Referring to FIG. 11, the structure of the PLC-ECL which is thermally changed by the front junction technique of FIG. 5 is mostly the same. As shown in FIG. 9, a phase control section 1180 using a thermo-optic or electro-optic effect is inserted for the stability of the ECL oscillation mode. Parts not described in FIG. 11 will be referred to FIG. 5.

12A and 12B are top views and side-views of multi-mode operation ECL arrays as examples of an optical transmission module (TOSA) of an OLT using a surface bonding technique according to an embodiment of the present invention. Indicates.

12A and 12B, the waveguide 1240 of the PLC may use polymer, silica, nitride, or the like. The FP-LD array 1220 'forms an ECL array in a one-to-one correspondence with a WBG array having a reflection band at a frequency interval recommended by the ITU-T. Each ECL sets the center wavelength of the reflection band of the corresponding WBG so that the WDM optical signal with a predetermined frequency interval can be transmitted, and the reflection bandwidth is 3 to 5 ECL cavity modes within the WBG reflection band so that the reflection bandwidth can be oscillated in multimode. Set the reflector bandwidth so that it exists.

The multi-wavelength optical signals at the output of the ECL array are wavelength-multiplexed by the WDM MUX 1290 monolithicly integrated into one PLC chip for final output. As such, by integrating the ECL array and the WDM MUX 1290 on one PLC, the optical fiber pigtail process of the optical transmission module can be simplified to one. The WDM MUX 1290 may be integrated with an arrayed-waveguide grating (AWG), a WDM filter, or the like.

A semiconductor chip 1220 that generates light is formed in the form of an FP-LD array 1220 '. The method of using individual FP-LD chips for each ECL has a problem of a long process time during manual alignment using a flip-chip bonding method, and a problem that the bonded chips are distorted when bonding other chips. In FIG. 12, the above problems are solved by using an FP-LD array 1220 ′. A monitor PD (mPD) 1210 is also formed in the form of an mPD array 1210 'to monitor the optical output power of each ECL module.

13A and 13B are top views and side-views of single-mode operation ECL arrays as another example of an optical transmission module (TOSA) of an OLT using a surface bonding technique according to an embodiment of the present invention. ).

Referring to FIGS. 13A and 13B, each ECL has a reflection band center wavelength of a corresponding WBG so that a WDM optical signal with a predetermined frequency interval can be transmitted, and the reflection bandwidth is an ECL cavity mode 1 so that a single-mode oscillation can be performed. Set the reflection bandwidth so that dogs are in the WBG reflection band. A phase-control section (1380) for the stability of single oscillation mode and fine tuning of oscillation wavelength is inserted. Phase control section 1380 has a heater or electrode formed on top of the waveguide to take advantage of thermo-optic or electro-optic effects. A portion not described in FIG. 13 will be described with reference to FIG. 12.

14A and 14B are top views and side-views of multi-mode operation ECL arrays as examples of an optical transmission module (TOSA) of an OLT using a front junction technique according to an embodiment of the present invention. Indicates.

The PLC waveguide 1440 may use polymer, silica, nitride, or the like. The FP-LD array 1420 'forms an ECL array in a one-to-one correspondence with a WBG array having a reflection band at a frequency interval recommended by the ITU-T. In each ECL, the center wavelength of the reflection band of the corresponding WBG is set so that the WDM optical signal with a predetermined frequency interval can be transmitted, and the reflection bandwidth is 3 to 5 ECL cavity modes in the WBG reflection band so that the multi-mode can be oscillated. Set the reflection bandwidth so that it exists inside.

The multi-wavelength optical signals at the output of the ECL array are wavelength-multiplexed by the WDM MUX 1490 monolithicly integrated on a PLC chip for final output. As such, by integrating the ECL array and the WDM MUX 1490 on one PLC, the optical fiber pigtail process of the optical transmission module 110 may be simplified to one. The WDM MUX 1490 may be integrated with an arrayed-waveguide grating (AWG), a WDM filter, or the like.

15A and 15B are top views and side-views of single mode operation ECL arrays as another example of an optical transmission module (TOSA) of an OLT using a front bonding technique according to an embodiment of the present invention. Indicates.

15A and 15B, each ECL has a reflection band center wavelength of a corresponding WBG so that a WDM optical signal with a predetermined frequency interval can be transmitted, and the reflection bandwidth is one WCL with one ECL cavity mode to generate a single mode. Set the reflection bandwidth so that it is within the reflection band. A phase control section (1580) has been inserted for the stability of the single oscillation mode and for fine tuning of the oscillation wavelength. Phase control section 1580 has a heater 1550 over PLC waveguide 1540 to take advantage of thermo-optic or electro-optic effects. A portion not described in FIG. 15 will be described with reference to FIG. 14.

16A and 16B illustrate a top view and a side-view of an OLT optical receiving module (ROSA) using a surface bonding technique according to an embodiment of the present invention, respectively.

16A and 16B, the PLC waveguide 1640 may use polymer, silica, nitride, or the like. The multi-wavelength optical signals input from the optical fiber 1670 are inputted to the PD 1620 by wavelengths separated by the WDM DMX 1690 monolithicly integrated into a PLC chip. WDM DMX 1690 is integrated on the PLC to simplify the fiber pigtail process into one. The WDM DMX 1690 may be integrated with an arrayed-waveguide grating (AWG), a WDM filter, or the like.

The semiconductor photodetector (PD) 1620 is comprised of a passive waveguide region (sending incident light to the active waveguide region using directional coupling) 1622 and an active waveguide region (region detecting the intensity of the incident light) 1624. It is surface bonded on a PLC chip in which the WDM DMX 1690 is integrated. For ease of the alignment process with the PLC waveguide 1640, the semiconductor substrate is formed in a PD array 1620 'rather than an individual semiconductor chip.

17A and 17B show side and plan views, respectively, of an example of ONT-ROSA that is wavelength-variable by heat based on a front coupled ECL.

The semiconductor photodetector used in FIG. 17A has no passive waveguide region and is optically coupled to the PLC waveguide 1740 in a front junction. A portion not described in FIG. 17 will be described with reference to FIG. 16.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD_ROM, magnetic tape, floppy disks, and optical data storage, and may also include those implemented in the form of carrier waves (eg, transmission over the Internet). . The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

As described above, optimal embodiments have been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The present invention relates to a WDM-PON system based on a wavelength variable external resonant laser light source has the following effects.

First, by proposing an integrated multi-wavelength optical transmission / reception module structure to be installed in a central office (CO), it is possible to solve the volume problem of the optical transmission / reception module generated when the CO accommodates a large number of subscribers based on the WDM-PON.

OLT's optical transmission module takes the form of adhering a Fabry-Perot laser (FP-LD) array (LD chip bar) onto a PLC (Planar Lightwave Circuit) and by waveguide bragg grating (WBG) arrays molded into the PLC. By designating the specific wavelengths from the cavity resonance conditions and shaping the WDM MUX in the PLC for multiplexing the WBG array output wavelengths, the key elements required by the OLT, such as simplification of packaging, productivity, performance and area efficiency, are compounded. Can be optimized.

OLT photoreceiving module takes the form of bonding Photo Detector (PD) array (PD chip bar) on PLC, forming WDM DMX to demultiplex input optical wavelength in the same PLC, and forming WDM DMX and PD array into PLC By connecting with waveguides, it is possible to compositely optimize key elements required by OLT, such as simplified packaging, yield, performance and area efficiency.                     

Second, it is possible to solve the low cost, mass production, ease of installation, and inventory management of the subscriber end device (ONT). In this regard, the uplink optical wavelength setting from ONT to OLT is set by transmitting the uplink wavelength information to the downlink optical signal from OLT to the corresponding ONT after the ONT is installed, or the corresponding ONT can automatically set the upward wavelength, or when installing ONT The user can manually set the upwave of the corresponding ONT. Therefore, the ONT is not designated a specific light wavelength, and may have a form in which the uplink light wavelength specified in the ONT is set by the control of the OLT or by the installer, so that the low cost, mass production, and installation of the subscriber end device (ONT) Ease of inventory and inventory management.

Third, since the output light is coherent in the PLC-ECL method proposed by the present invention, there is no spontaneous-spontaneous beating noise, and since the line width is sufficiently narrow, 2.5 Gbps data can be transmitted up to a distance of 20 km. Therefore, the method proposed by the present invention can improve the disadvantages of operation instability and transmission rate limitation of about 1Gbps according to the temperature change of the conventional injection-locking method. In addition, the device packaging including the optical fiber pigtail (pigtail) is a fully passive structure that can be mass-produced, it is possible to lower the cost compared to the optical device manufactured by the conventional active alignment packaging method.

Claims (36)

Wavelength first waveguide Bragg grating (WBG) is formed and consists of an optical transmitter consisting of a first external resonance laser (ECL) array for generating an optical wavelength for data transmission and an optical receiver consisting of a photodetector (PD) array. The optical transmitter has a first wavelength multiplexer (WDM MUX) for multiplexing a plurality of optical wavelengths output from the first external resonant laser array, and the optical receiver is configured to separate and receive the input multiplexed wavelengths for each wavelength. An optical line terminal (OLT) having one wavelength divider (WDM DMX); A light receiving unit for receiving the data wavelength for transmitting data transmitted from the OLT and a wavelength variable second waveguide Bragg grating (WBG) are formed and the second waveguide Bra grating according to the light wavelength for data transmission input from the OLT. A plurality of optical network terminals (ONTs) comprising an optical transmitter configured of a second external resonant laser (ECL) to control the temperature applied to the optical wave; A second channel located in a main distribution frame (MDF) near the plurality of ONTs and dividing the multiplexed optical wavelengths transmitted through the optical fiber from the first wavelength multiplexer of the OLT by wavelength to connect each optical wavelength to a corresponding ONT among the ONTs; Wavelength divider (WDM DMX); And A second wavelength multiplexer (WDM) located in a main distribution frame (MDF) near the plurality of ONTs and multiplexing a plurality of optical wavelengths output from the optical transmitters of the plurality of ONTs and transmitting the multiplexed optical wavelengths to the first wavelength distributor of the OLT through an optical fiber; WDM-PON system based on wavelength variable external resonant laser light source including MUX). The method of claim 1, Downlink wavelength information for dividing the optical wavelength multiplexed from the OLT by the second wavelength divider by wavelength and connecting each optical wavelength to a corresponding ONT among the ONTs is stored as network setting information in the OLT. WDM-PON system based on external resonance laser light source. The method of claim 1, The uplink wavelength information of the ONT determined by the input port of the WDM MUX located near the ONT at the output port of the second wavelength multiplexer is also stored as network setting information in the OLT as network setting information, so that the ONT WDM-PON system with automatic uplink wavelength setup. The method of claim 1, The waveguide Bragg grating is a WDM-PON system based on a wavelength variable external resonant laser light source, characterized in that the reflection center wavelength and bandwidth is set to have a predetermined frequency interval. In the wavelength division multiplex passive optical subscriber network (WDM-PON) system, An optical transmitter configured of an external resonant laser (ECL) array for generating an optical wavelength for data transmission by forming a waveguide Bragg grating (WBG) in a planar waveguide circuit (PLC); A wavelength multiplexer (WDM MUX) for multiplexing a plurality of optical wavelengths output from an external resonance laser (ECL) array of the optical transmitter; A wavelength divider (WDM DMX) for separating and distributing the multiplexed optical wavelengths inputted from an optical network terminal (ONT) for each wavelength; And An optical line terminal (OLT) based on a tunable external resonant laser light source, comprising: a light receiving unit comprising a photodetector (PD) array for detecting an optical wavelength distributed from the wavelength divider (WDM DMX). The method of claim 5, wherein the optical transmitter And an optical fiber pigtail output to the ONT by forming the planar waveguide circuit on the same chip as the external resonant laser array and the wavelength multiplexer. The method of claim 5, wherein the external resonant laser array A semiconductor optical transmission chip composed of a Fabry-Perot laser diode (FP-LD) array is bonded onto the planar waveguide circuit, And the waveguide Bragg grating array formed in the planar waveguide circuit corresponds to the Fabry-Perot laser diode array. The method of claim 7, wherein the optical transmitting unit An OLT based wavelength variable external resonant laser light source, characterized in that the waveguide Bragg grating is formed at a predetermined point on the PLC waveguide between the V-groove to which the optical fiber is bonded and the Fabry-Perot laser diode. The method of claim 7, wherein When the temperature applied to the waveguide Bragg grating is changed, the effective refractive index of the PLC waveguide is changed correspondingly, so that the optical wavelength for data transmission of the external resonance laser array is changed. OLT as one. The method of claim 7, wherein And a monitoring photodetector (mPD) array formed around the Fabry-Perot laser diode to monitor the optical power of the optical wavelength generated by the Fabry-Perot laser diode. Based on OLT. The method of claim 7, wherein Wherein the semiconductor optical transmission chip is bonded to the flat waveguide circuit such that the waveguide formed in the semiconductor optical transmission chip and the PLC waveguide formed in the flat waveguide circuit are coupled in a surface bonding manner. OLT based on variable external resonance laser light source. The method of claim 7, wherein Wherein the semiconductor optical transmission chip is bonded to the flat waveguide circuit such that the waveguide formed in the semiconductor optical transmission chip and the PLC waveguide formed in the flat waveguide circuit are coupled in a front-junction manner. OLT based external laser light source. The method of claim 7, wherein Based on the wavelength variable external resonant laser light source, a plurality of the external resonant laser resonance mode (cavity mode) is included in the reflected wavelength band of the waveguide brogg grid to reduce the mode hopping phenomenon due to temperature and input current. OLT as one. The method of claim 7, wherein When the external resonance laser cavity mode is included in the reflection wavelength band of the waveguide brogg grid, And a phase control unit for controlling a phase matching condition of the external resonance laser resonance between the Fabry-Perot laser diode and the waveguide brogg grid. The method of claim 7, wherein OLT based on wavelength variable external resonant laser light source, characterized in that for outputting the corresponding optical wavelength for the data transmission through the change of the external resonance conditions due to the thermo-optic effect of the waveguide Bragg grating formed in the plate-type waveguide circuit . The method of claim 5, wherein the light receiving unit And an optical fiber pigtail input from the ONT by forming a planar waveguide circuit on the same chip as the photodetector array and the wavelength divider. The method of claim 16, The semiconductor light receiving chip is bonded to the flat waveguide circuit such that the waveguide formed in the semiconductor light receiving chip constituting the photodetector array and the PLC waveguide formed in the flat waveguide circuit are coupled in a surface bonding manner. OLT based on wavelength variable external resonant laser light source. The method of claim 16, Wherein the semiconductor light receiving chip is bonded to the flat waveguide circuit such that the waveguide formed in the semiconductor light receiving chip constituting the photodetector array and the PLC waveguide formed in the flat waveguide circuit are coupled in a front-junction manner. OLT based on wavelength variable external resonant laser light source. In the wavelength division multiplex passive optical subscriber network (WDM-PON) system, An optical receiver (Rx) for receiving an optical wavelength transmitted from an optical line terminal (OLT) and converting the optical wavelength into an electrical signal; A DCC (data control center) for receiving the optical wavelength converted from the optical receiver into an electrical signal and separating the optical wavelength transmitted from the OLT into general data and WBG control data; A WCC (wavelength control center) for receiving an input of the WBG control data from the DCC and controlling an uplink optical wavelength for uplink data transmission by adjusting a temperature of a waveguide brogg grid (WBG) according to the WBG control data; And An optical network terminal (ONT) based on a tunable external resonant laser light source, characterized in that it comprises an external resonant laser (ECL) for modulating the uplink data to the uplink optical wavelength to transmit to the optical termination device (OLT). The method of claim 19, ONT based on a tunable external resonant laser light source, characterized in that for fixing the upward optical wavelength at the time of the ONT installation. The method of claim 19, The OLT transmits uplink optical wavelength information to the corresponding ONT to control the uplink optical wavelength transmitted from the corresponding ONT to the OLT through the downlink optical wavelength set in the corresponding ONT among the plurality of ONTs. ONT based on wavelength variable external resonant laser light source. The method of claim 21, When the ONT receives the uplink optical wavelength information through the downlink optical wavelength transmitted from the OLT, the ONT transfers the uplink optical wavelength information to the WCC, The WCC supplies a predetermined current to the wavelength control unit of the external resonant laser to be tuned to the corresponding upward optical wavelength, ONT based on a tunable external resonant laser light source, characterized in that when the tuning is made to the uplink optical wavelength, the uplink data is modulated to the uplink optical wavelength and transmitted to the OLT. The method of claim 19, When the reception sensitivity information of the optical wavelength received from the OLT is separated from the DCC and transmitted to the WCC, The WCC adjusts the reflection center wavelength of the waveguide brogg grating based on the optical wavelength received from the OLT by adjusting the temperature of the waveguide Bragg grating through the previously stored reception sensitivity information. ONT based on resonant laser light source. The method of claim 19, wherein the external resonant laser A semiconductor chip consisting of a Fabry-Perot laser diode (FP-LD) is bonded onto the planar waveguide circuit (PLC), The waveguide Bragg grating formed in the planar waveguide circuit is formed so as to correspond to the Fabry-Perot laser diode ONT based on a tunable external resonant laser light source. The method of claim 24, The external resonance laser further includes a monitoring photodetector (mPD) for monitoring the output of the external resonance laser, And the monitoring photodetector feeds back a photodetection signal to the WCC to monitor the light output of the external resonant laser. The method of claim 24, The ONT outputs a corresponding designated optical wavelength through a change in an external resonance condition due to the thermo-optic effect of the waveguide Bragg grating formed in the plate-type waveguide circuit. . The method of claim 24, The semiconductor chip made of the Fabry-Perot laser diode is ONT based on a wavelength variable external resonant laser light source, characterized in that bonded to the flat waveguide circuit by a surface bonding method. The method of claim 24, The Fabry-Perot laser diode is a passive optical waveguide region for generating light and a passive waveguide region for coupling light generated in the semiconductor optical amplification region to a PLC waveguide in the planar waveguide circuit. ONT based on a wavelength variable external resonant laser light source, characterized in that consisting of semiconductor chips. The method of claim 28, The passive waveguide region is an ONT based on a variable wavelength external resonant laser light source, characterized in that the size of the light beam generated in the semiconductor optical amplification region is increased to increase the optical coupling efficiency. The method of claim 24, The optical wavelength output through the optical fiber is ONT based on a tunable external resonance laser light source, characterized in that determined by the external cavity (external cavity) generated in the semiconductor chip and the flat waveguide. The method of claim 24, Based on the wavelength variable external resonant laser light source, a plurality of the external resonant laser resonance mode (cavity mode) is included in the reflected wavelength band of the waveguide brogg grid, thereby reducing mode hopping due to temperature and input current. ONT. The method of claim 24, When the external resonance laser cavity mode is included in the reflection wavelength band of the waveguide brogg grid, And a phase adjusting unit for controlling a phase matching condition of the external resonance laser resonance between the Fabry-Perot laser diode and the waveguide brogg grid. The method of claim 32, Wavelength variability, characterized in that to change the temperature applied to the waveguide brogg grid or to change the current applied to the Fabry-Perot laser diode to suppress the mode hopping phenomenon that the center wavelength output from the external resonance laser is shifted ONT based on external resonance laser light source. The method of claim 24, The semiconductor chip is bonded to the planar waveguide circuit such that the waveguide formed in the semiconductor chip and the PLC waveguide formed in the planar waveguide circuit are bonded to the planar waveguide circuit. ONT. The method of claim 24, The semiconductor chip is bonded to the planar waveguide circuit such that the waveguide formed in the semiconductor chip and the PLC waveguide formed in the planar waveguide circuit are front bonded to each other. ONT. In a wavelength division multiplex passive optical subscriber network (WDM-PON) system, the optical wavelength control method of the UPT (Optical Network Terminal), (a) an optical line terminal (OLT) determining an uplink optical wavelength of the ONT corresponding to a downlink optical wavelength predetermined for an ONT which is connected to a network and wants to transmit to the newly installed ONT; (b) the OLT loading the uplink optical wavelength information determined in the step (a) to the downlink optical wavelength determined in the ONT and transmitting the information to the ONT; (c) the ONT generating an upward optical wavelength through the upward optical wavelength information transmitted by being loaded on the downward optical wavelength from the OLT in the step (b); And (d) The ONT uplink wavelength control method of the ONT in the WDM-PON system comprising the step of transmitting the uplink data in the uplink optical wavelength generated in the step (c) to the OLT.

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