KR101247852B1 - Multi-channel wavelength division multiplexing optical source photonic intergration method and optical module using the same - Google Patents

Abstract

The present invention relates to the field of optical communication, and more particularly, to a method for integrating a multi-channel wavelength division multiple light source and an optical module therefor. The optical module of the present invention is a wavelength division comprising a lattice filter which is closely connected to at least one wavelength independent light source and at least one wavelength independent light source and corresponds to the central wavelength of each channel port of the wavelength division multiplexer. And a medium coupled reflection filter.

Description

MULTI-CHANNEL WAVELENGTH DIVISION MULTIPLEXING OPTICAL SOURCE PHOTONIC INTERGRATION METHOD AND OPTICAL MODULE USING THE SAME}

TECHNICAL FIELD The present invention relates to the field of optical communications, and more particularly, to a method for integrating a multi-channel wavelength division multiple light source and an optical module using the same.

Representative light sources used as optical communication light sources include (a) Fabry Perot Laser Diode (FP LD) and (b) Distributed FeedBack Laser Diode (DFB LD) as shown in FIG. 1. The FP LD 10 is a light source having the simplest structure and includes both reflective surfaces 1 and 3 of a diode including a gain medium 2. The DFB LD 20 is a periodic grating 4 and, if necessary, a temperature control element 5 in addition to both reflective surfaces 1 and 3 and a gain medium 2 for use as a light source for wavelength division multiplexing (WDM). It is driven at a specific wavelength by adding

)을 갖는 적어도 하나의 DFB LD(20a, 20b, 20c)와 파장분할다중기(50)를 PLC(Photonic Lightwave Circuit) 기술을 이용하여 집적화한다.Recently, research and development on the integration of multi-channel WDM light sources combining multiple wavelength light source wavelength division multiplexers have been actively conducted to realize miniaturization, low cost, and low power. 2 is an exemplary view showing an integrated method of a conventional proposed multichannel WDM light source, and has different center wavelengths (

At least one DFB LD (20a, 20b, 20c) and the wavelength division multiplexer (50) having a) are integrated using a PLC (Photonic Lightwave Circuit) technology.

3 is another exemplary view illustrating a conventional multichannel WDM light source integration method, wherein at least one FP LD (10a1, 10a2, ..., 10aN), a wavelength division multiplexer 50, which is a light source capable of wavelength independent operation, is shown. ) And the reflector 30 using the PLC technology to implement a wavelength independent multi-channel WDM light source.

)을 가지며, 각 채널 포트에 1대1로 연결되는 DFB LD(20a, 20b, 20c)에는 각 채널포트의 중심 파장에 맞도록 주기적 격자(4)의 간격이 조정되어 제작된다. 파장 간격이 좁은 DWDM(Dense WDM)의 경우 추가적으로 열전 소자 또는 히터(heater) 등의 국부적인 온도 제어 소자를 이용하여 정교하게 DFB LD(20a, 20b, 20c)의 파장을 각 채널 포트의 중심파장에 맞출 수 있다. 이와 같은 방법을 이용하여 DFB LD(20a, 20b, 20c)를 파장분할다중기(50)의 각 채널 포트에 연결하는 PLC 집적기술로 다채널 WDM 광통신용 광원을 생성할 수 있다.The operation principle of the multi-channel WDM light source 100 using the DFB LDs 20a, 20b, and 20c illustrated in FIG. 2 is as follows. The wavelength division multiplexer 50 has different center wavelengths for each number of channel ports to be multiplexed.

DFB LDs 20a, 20b, and 20c connected to each channel port in a one-to-one manner are manufactured by adjusting the interval of the periodic grating 4 to match the center wavelength of each channel port. In the case of DWDM (Dense WDM) with narrow wavelength spacing, a local temperature control element such as a thermoelectric element or a heater is used to precisely convert the wavelength of the DFB LD (20a, 20b, 20c) to the center wavelength of each channel port. Can be adjusted. Using such a method, a multi-channel WDM optical communication light source can be generated by a PLC integrated technology that connects the DFB LDs 20a, 20b, and 20c to each channel port of the wavelength division multiplexer 50.

)에서 동작이 가능한 넓은 이득 선폭을 갖는 LD(10a1, 10a2,...,10aN)를 파장분할다중기(50)의 각 채널포트에 1대1로 연결하되, 도 1 (a)에 예시된 바와 같은 구조를 갖는 FP LD(10a1, 10a2,...,10aN)의 전면 반사면(1)의 반사율은 높은 반사율을 가지며 후면 반사면(3)은 낮은 반사율을 갖도록 제작한다. 또한 상기 파장분할다중기(50)의 출력 포트에는 전 채널 포트의 파장에 대하여 높은 반사율을 갖는 반사체(30)를 연결한다. 이러한 구조에서는 각 채널 포트 파장에서 발진하는 다채널 WDM 광원이 형성된다. 예를 들어, N번 채널 포트의 경우 FP LD(10aN)의 전면 반사면(1)과 반사체(30)에 의해 형성된 공진기의 양 반사면, FP LD의 이득매질(2) 및 파장분할다중기의 N번 포트에 의하여 결정되는

을 중심파장으로 하는 필터에 의하여,

의 중심파장에서 발진하는 단일 파장 광원이 형성된다. 파장분할다중기(50)는 이러한 채널 파장 다수(

)를 다중화하므로 반사체(30)가 연결된 출력 포트에서는 다채널 WDM 광원을 생성할 수 있다.The operating principle of the wavelength independent multi-channel WDM light source 200 illustrated in FIG. 3 is as follows. All channel port wavelength ranges of the wavelength division multiplexer 50

LD (10a1, 10a2, ..., 10aN) having a wide gain line width that can be operated in the (1) to 1 to 1 each channel port of the wavelength division multiplexer 50, as shown in Figure 1 (a) The reflectance of the front reflective surface 1 of the FP LDs 10a1, 10a2, ..., 10aN having the structure as described above is manufactured to have a high reflectance and the rear reflective surface 3 to have a low reflectance. In addition, the output port of the wavelength division multiplexer 50 is connected to the reflector 30 having a high reflectance with respect to the wavelength of all channel ports. In this structure, a multichannel WDM light source oscillating at each channel port wavelength is formed. For example, in the case of the N port, the front reflection surface 1 of the FP LD 10aN and the reflection surface of the resonator formed by the reflector 30, the gain medium 2 of the FP LD, and the wavelength division multiplexer Determined by port N

By filter centering on

A single wavelength light source oscillating at the central wavelength of is formed. The wavelength division multiplexer 50 has a number of such channel wavelengths (

), The output port to which the reflector 30 is connected can generate a multi-channel WDM light source.

Although the multi-channel WDM light sources 100 and 200 shown in FIGS. 2 and 3 are technologies capable of miniaturization and low power by PLC integrated technology, there are problems to be overcome. In the case of the multi-channel WDM light source 100 using the conventional DFB LD, there is a problem in that supplying components is difficult due to the need of DFB LDs having different wavelengths as the number of wavelengths of each channel, and the price of the DFB LD is high. There is a disadvantage that the manufacturing cost of the product increases. In the case of the conventional multichannel WDM light source 200 using the wavelength independent FP LD, the problem of using the DFB LD using the same FP LDs (10a1, 10a2, ..., 10aN) is overcome. The wavelength division multiplexer 50 is positioned between the FP LD front reflecting surface 1 and the reflector 30 so that the resonator length is increased by the length of the wavelength division multiplexer 50 (typically a few cm), thereby enabling high speed operation. There is a problem that the stability may be deteriorated due to the reflection of the reflection in the wavelength division multiplexer 50 existing in the resonator.

The present invention provides a method for integrating a multi-channel wavelength division multiple light source and an optical module using the same.

The multi-channel wavelength division multiple light source integration optical module of the present invention comprises: at least one wavelength independent light source; And a wavelength division multiplexer coupled reflection filter coupled to the at least one wavelength independent light source and including a lattice structure filter corresponding to the center wavelength of each channel port of the wavelength division multiplexer.

In addition, the multi-channel wavelength division multiple light source integration method of the present invention includes forming a lattice structure filter on the wavelength division multiplexer coupled reflection filter in close proximity to the at least one wavelength independent light source.

According to the present invention, a wavelength-independent multichannel WDM (wavelength division multiplexing) light source is a conventional multichannel WDM light source using a DFB LD (Distributed FeedBack Laser Diode) light source due to the use of DFB LD having different wavelengths as many as the number of channels. It is possible to achieve low price by solving parts supply problem and high price problem. In addition, the conventional wavelength-independent multi-channel WDM light source has a long resonator, so that high speed operation is difficult and stability is solved. Thus, stable and high speed operation is possible. In addition, the wavelength division multiplexer and the grating structure can be designed on a single photonic lightwave circuit (PLC) substrate, thereby simplifying the manufacturing process and reducing the cost.

1 is an exemplary view showing a light source.
2 and 3 is an exemplary view showing an integration method of a multi-channel WDM light source.
4 is an exemplary wavelength independent multi-channel WDM light source directing module according to an embodiment of the present invention.
5 is an exemplary diagram of a wavelength design of a wavelength division multiplexer and a combined reflection filter according to an exemplary embodiment of the present invention.
6 is an illustration of an array modularized wavelength independent multichannel WDM light source module according to an embodiment of the invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the following description, in order not to unnecessarily obscure the subject matter of the present invention, a method such as manufacturing an electrode for constructing an optical communication transmitter to use an optical communication light source corresponding to a known function or configuration, and a laser diode (LD) A description of a general method of integrating a wavelength division multiplexer and the like using a PLC (Photonic Lightwave Circuit) technology will be omitted.

The present invention implements a wavelength-independent multichannel WDM light source capable of stable and high-speed operation, and thus, an expensive structure of a multichannel WDM light source using a conventional DFB (Distributed FeedBack) and a longer resonator length of a conventional wavelength independent multichannel WDM light source. To solve the disadvantages caused by.

)에 해당하는 격자구조 필터(40a, 40b,...,40c)를 포함하는 파장분할다중기 결합 반사필터(60)와, 높은 반사율의 전면 반사면(1)과 낮은 반사율의 후면 반사면(3)을 갖는 적어도 하나의 파장 무의존성 LD(10a1, 10a2,...,10aN)가 근접 연결하되, 상기 파장 무의존성 LD(10a1, 10a2,...,10aN)의 양 반사면 중 상기 격자구조 필터와 연결되는 부분은 낮은 반사율을 갖도록 구성하여 하나의 파장 무의존성 다채널 WDM 광모듈(300)이 된다. 파장 무의존성 다채널 WDM 광모듈(300)으로써 파장 간격이 좁은 DWDM(dense WDM) 광통신 광원에 사용될 때는 격자구조 필터(40a, 40b,..., 40c)에 국부적으로 온도를 변화시킴으로써 격자 간격의 변화를 유발하여 정교한 파장 조정을 가능하게 하는 온도 제어 소자(45a, 45b,..., 45c)를 추가로 구성할 수 있다. 온도 제어 소자(45a, 45b,..., 45c)는 열전 소자(Thermo-Electric Cooler) 또는 히터(heater) 등으로 구현이 가능하다. 각 파장 무의존성 LD(10a1, 10a2,..., 10aN)와 파장분할다중기(50)는 PLC 상의 광경로 도파로에 의하여 버트 커플링(butt coupling) 등의 방법으로 연결되며, 격자구조 필터(40a, 40b,..., 40c)는 각 파장 무의존성 LD(10a1, 10a2,..., 10aN)와 최대한 근접한 광경로 도파로 상에 위치하게 된다.
4 is As a configuration diagram of a wavelength independent multi-channel WDM (wavelength division multiplexing) light source according to an embodiment of the present invention, a corresponding center wavelength of each channel port of the wavelength division multiplexer 50 (

A wavelength division multiplexer coupled reflection filter 60 comprising a lattice filter (40a, 40b, ..., 40c) corresponding to the above, a high reflectance front reflecting surface (1) and a low reflectance rear reflecting surface ( 3) at least one wavelength independent LD (10a1, 10a2, ..., 10aN) having a close connection, the grating of the two reflection surfaces of the wavelength independent LD (10a1, 10a2, ..., 10aN) The portion connected to the structure filter is configured to have a low reflectance to become one wavelength independent multichannel WDM optical module 300. When used as a wavelength-independent multichannel WDM optical module 300 for a dense WDM optical communication light source with a narrow wavelength spacing, the temperature of the lattice spacing may be changed by locally changing the temperature of the lattice filters 40a, 40b, ..., 40c. The temperature control elements 45a, 45b, ..., 45c can be further configured to cause a change and enable fine wavelength adjustment. The temperature control elements 45a, 45b,..., 45c may be implemented as a thermo-electric cooler or a heater. Each wavelength independent LD (10a1, 10a2, ..., 10aN) and the wavelength division multiplexer 50 are butted by an optical path waveguide on the PLC. Grating filters 40a, 40b,..., And 40c are connected by a method such as butt coupling, and the optical path waveguides as close as possible to the wavelength independent LDs 10a1, 10a2..., 10aN. It is located in the phase.

The wavelength division multiplexer coupled reflection filter 60 constituting the wavelength independent multi-channel WDM optical module 300 according to an exemplary embodiment has a center of each channel port of the wavelength division multiplexer 50 as shown in FIG. 5. The spacings of the lattice filters 40a, 40b, ..., 40c are manufactured so that the wavelength and the reflectance center wavelengths of the lattice filters 40a, 40b, ..., 40c connected to each channel port coincide. The lattice filters 40a, 40b,..., 40c serving as the wavelength division multiplexer 50 and the reflection filter function as passive optical devices, making it easy to manufacture a single PLC substrate layer. When used in DWDM optical communication light sources with narrow wavelength spacing, the temperature control element 45a can change the lattice spacing by locally changing the temperature in the lattice filters 40a, 40b, ..., 40c to enable fine wavelength adjustment. , 45b, ..., 45c) and the addition of an electrode and an additional control circuit can be configured to obtain the desired wavelength accuracy.

When at least one wavelength independent LD (10a1, 10a2, ..., 10aN) is closely connected to the wavelength division multiplexer coupled reflection filter 60, each wavelength independent LD (10a1, 10a2, ..., 10aN) The grating filters 40a, 40b,..., 40c serving as the reflecting filter 1 and the front reflecting surface 1 of the two reflecting surfaces forming the laser resonator, at least one wavelength independent LD (10a1, 10a2) In addition to the gain medium 2 included in ..., 10aN), an LD light source having a center wavelength corresponding to each channel port is formed.

)에서 정의되는 효과 반사면의 위치까지의 길이이다. The lattice filter 40a, 40b, ..., 40c has a high reflectance and a low reflectance periodically repeated at a predetermined length and has a maximum reflectance at a specific wavelength by the period length. Unlike the reflective surface of the conventional mirror surface, the position of the reflective surface of the present invention may be obscured by the periodic structure of the start point and the end point of the lattice filter 40a, 40b,. It can be defined as an effective reflection point at a wavelength having a wavelength, and the position of the effect reflection surface is present at an arbitrary point between the start point and the end point of the lattice filters 40a, 40b, ..., 40c. do. The effect length is the maximum reflectance wavelength (from the back reflecting surface 3 of wavelength independent LDs 10a1, 10a2, ..., 10aN).

The length to the position of the effect reflecting surface as defined in.

)을 갖게 된다.For example, in the case of the N-th channel port, both reflection surfaces of the laser are formed by the lattice filter 40c serving as a reflection filter and the front reflection surface 1 of the wavelength independent LD 10aN, and the wavelength independent LD. Together with the gain medium 2 of 10aN, a laser is constituted. The rear reflecting surface 3 of the wavelength independent LD 10aN is designed to have a reflectance as low as possible so that there is no reflection effect on the optical path. In this case, the lattice filter 40c serves as a reflection filter having the maximum reflectance at the center wavelength of the N-th channel port of the wavelength division multiplexer 50. Thus, the lattice filter 40c is composed of the wavelength-independent LD 10aN and the lattice filter 40c. The laser has a center wavelength consistent with the filter center wavelength of the Nth channel port of the wavelength division multiplexer 50.

).

)을 갖는 레이저들의 출력을 각 채널 포트를 통하여 전달받아 출력 포트로 다중화하여 파장 무의존성 다채널 WDM 광모듈(300)을 형성한다.The wavelength division multiplexer 50 is formed by combining at least one wavelength independent LD (10a1, 10a2, ..., 10aN) with at least one lattice filter (40a, 40b, ..., 40c). The center wavelength corresponding to the port (

Receiving the output of the laser having a) through each channel port and multiplexed to the output port to form a wavelength independent multi-channel WDM optical module 300.

In the wavelength-independent multichannel WDM optical module 300 of the present invention, the length of the resonator is the front reflection surface 1 and the lattice filter 40a, 40b of the wavelength-independent LDs 10a1, 10a2, ..., 10aN. Since the resonator is short and is formed irrespective of the wavelength division multiplexer 50, it can be used as a multi-channel WDM light source capable of stable and high speed optical communication. For example, if the length of wavelength independent LD (10a1, 10a2, ..., 10aN) is 300 um and the effect length by the lattice filter (40a, 40b, ..., 40c) is 300 um, the total resonator The length is 600 um, and in the case of the conventional wavelength independent multichannel WDM optical module 200, it is tens of times smaller than several cm, which is the length of the resonator dominantly determined by the length of the wavelength division multiplexer 50. It is easy to design without problems in high speed operation.

In another embodiment according to the present invention, the wavelength-division multiplexer combined reflection filter 60 and the wavelength-independent LDs are modularized to facilitate PLC fabrication of a multi-channel WDM light source and to lower production costs. There is a way to make it. FIG. 6 is a schematic diagram of an array-modulated wavelength independent multichannel WDM optical module 400 according to an embodiment of the present invention, wherein at least one wavelength independent LD 10a1, 10a2, ..., 10aN, 10b1, 10b2, Combining the wavelength division multiplexer using at least one wavelength independent light source array module (70a, 70b, ..., 70c) using ..., 10bN, ..., 10c1, 10c2, ..., 10cN It is closely connected to the reflection filter 60.

If the spacing between the LDs of the wavelength independent light source array modules 70a, 70b, ..., 70c is designed to match the spacing of the corresponding channel ports of the wavelength division multiplexer combined reflection filter 60, the number of channels is multichannel. When manufacturing a WDM light source, the manufacturing process is simplified compared to the case of connecting each LD individually, thereby lowering the manufacturing cost.

While the above methods have been described through specific embodiments, the methods may also be implemented as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

Although the present invention has been described in connection with some embodiments thereof, it should be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention as understood by those skilled in the art. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

1, 3: Reflective surface 2: Gain medium
4, 40: lattice filter 5, 45: temperature control element
10, 20: light source 30: reflector
50: wavelength division multiplexer 60: wavelength division multiplexer combined reflection filter
70: wavelength independent light source array module
100, 200, 300, 400: multichannel optical module

Claims (10)

A multi-channel wavelength division multiple light source integration optical module,
At least one wavelength independent light source; And
A wavelength division multiplexer coupled reflection filter in close proximity to the at least one wavelength independent light source and including a lattice structure filter corresponding to the center wavelength of each channel port of the wavelength division multiplexer,
And placing the wavelength division multiplexer and the grating filter on a photonic lightwave circuit (PLC) substrate. The method of claim 1,
And the at least one wavelength independent light source comprises a front reflecting surface having a higher reflectance than a rear reflecting surface and a rear reflecting surface having a reflectance lower than the front reflecting surface. The method of claim 1,
The wavelength division multiplexer coupled reflection filter further includes a temperature control element for locally changing the temperature of the lattice structure filter to cause a change in lattice spacing to enable precise wavelength adjustment. The method of claim 1,
And the grating structure filter has a maximum reflectance center wavelength matched within a predetermined range with a transmission center wavelength of a corresponding channel port of the wavelength division multiplexer. The method of claim 1,
And the at least one wavelength independent light source and the wavelength division multiplexer are connected by an optical path waveguide on the PLC, and the grating structure filter is located on the optical path waveguide as close as possible to the wavelength independent light source. The method of claim 1,
And modularize the at least one wavelength independent light source to connect with the wavelength division multiplexer coupled reflection filter. A multichannel wavelength division multiple light source integration method,
Forming a lattice structure filter on the wavelength division multiplexer coupled reflection filter in close proximity to at least one wavelength independent light source and having a wavelength corresponding to the center wavelength of each channel port of the wavelength division multiplexer;
Disposing the wavelength division multiplexer and the grating filter on a photonic lightwave circuit (PLC) substrate. The method of claim 7, wherein
Locally changing the temperature of the grating filter to cause a change in grating spacing to enable fine wavelength adjustment. The method of claim 7, wherein
The at least one wavelength independent light source is connected by the wavelength division multiplexer coupled reflection filter and the optical path waveguide on the PLC, and the grating structure filter is positioned on the optical path waveguide as close as possible to the wavelength independent light source. , Multi-channel wavelength division multiple light source integration method. The method of claim 7, wherein
And modularizing the at least one wavelength independent light source with the wavelength division multiplexer coupled reflection filter.

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