KR100416983B1 - Alignment element for planar lightguide circuit module - Google Patents

Abstract

The present invention provides a device for aligning a planar optical waveguide device in which an input port and an output port are arranged on the same surface by performing a multiplexing / demultiplexing function using a waveguide grating in a wavelength division multiplex communication method. A dummy input port disposed at the other side; One end is connected to the dummy input port, and the other end is connected to the waveguide column grating, and includes a dummy input waveguide for providing a path through which the optical signal input through the dummy input port travels. The planar optical waveguide device having the configuration described above is easy to align the optical fiber blocks by aligning the planar optical waveguide device and the optical fiber blocks while inputting a wideband optical signal to the dummy input waveguide, and shortens the time required for optical fiber block alignment. As a result, productivity has been improved.

Description

Alignment device of planar optical waveguide device module {ALIGNMENT ELEMENT FOR PLANAR LIGHTGUIDE CIRCUIT MODULE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar lightguide circuit (PLC), and more particularly, to an alignment device of a planar optical waveguide device module used in a wavelength division multiplexing / demultiplexing (MUX / DEMUX) communication system.

In a waveguide division multiplexing (WDM) communication system, which is commonly used to transmit a large amount of information, an optical signal having N wavelengths is simultaneously transmitted through a single fiber. In order to convert the received optical signal into an electrical signal, the receiving end must separate it into optical signals having respective wavelengths. The receiver of a wavelength division multiplexing system based on a single mode optical fiber mainly uses an arrayed waveguide grating (AWG) to separate an optical signal having multiple wavelengths into an optical signal having each wavelength.

The operation of the planar optical waveguide device using the optical waveguide thermal grating can be regarded as the diffraction grating of the planar optical waveguide device, and the dispersion characteristics due to diffraction of incident light can be described using a known grating equation.

In particular, the planar optical waveguide device directly fabricates an optical waveguide on a flat substrate by using a planar waveguide technology (PLC) for the purpose of optical signal processing such as branching, modulation, switching, and signal multiplexing of optical signals. Much research is being done on anger. As a technique required to fabricate such an optical waveguide device, for example, the design, fabrication, and packaging of the waveguide may be used. A typical optical waveguide is an optical transmission path that traps input light and propagates low loss in the longitudinal direction. The optical waveguide includes a core having a large refractive index and a cladding having a low refractive index surrounding the core. The optical waveguide device splits light using a difference in refractive index between a core and a cladding surrounding the core by depositing several layers of silica or polymer thin films on a silicon or quartz substrate, It changes the path of light or controls the intensity of light.

In general, a planar optical waveguide device includes an input port on one side of a semiconductor substrate, an input waveguide extending from the input port, and a plurality of output ports on the other side of the semiconductor substrate, and output waveguides extending from the output port. The input waveguide and the output waveguide are connected to each other through a grating portion composed of a plurality of waveguides. In order to perform multiplexing / demultiplexing using the planar optical waveguide device, an optical fiber block in which optical fibers and ribbon optical fibers are arranged is connected to the input port and the output port, respectively, wherein the optical fiber blocks are respectively input and output of the planar optical waveguide device. Not only decreases productivity due to time-consuming bonding, but also causes heat deformation such as adhesives during the alignment process to reduce the reliability of the product. Moreover, since two optical fiber blocks are used, the size and volume of the product Has the disadvantage of becoming larger.

In order to compensate for these disadvantages, planar optical waveguide devices having a configuration in which input ports and output ports are arranged on the same plane and combine only a single optical fiber block have appeared.

1 is an enlarged perspective view illustrating a planar optical waveguide device 100 module according to a conventional embodiment, and FIG. 2 is an enlarged view of an alignment portion between the planar optical waveguide device 100 and the optical fiber block 200 shown in FIG. 1. It is a top view shown by.

As shown in FIGS. 1 and 2, the planar optical waveguide device 100 module according to a conventional embodiment includes an input waveguide part 110, an output waveguide part 150, and an input waveguide part 110. A planar optical waveguide device 100 having a grating portion 130 interconnecting the output waveguide portion 150, an input port 111 of the input waveguide portion 110, and an output port of the output waveguide portion 150. The optical fiber block 200 having the optical fibers corresponding to the ones 151 are arranged, and the input port 111 of the input waveguide part 110 and the output port 151 of the output waveguide part 150 are disposed on the same plane. .

The input waveguide part 110 includes an input port 111 and an input waveguide extending from the input port 111 and connected to the grating part 130. The first shaping coupler 131 is positioned between the input waveguide part 110 and the grating part 130, and an optical signal having a plurality of wavelengths traveling through the input waveguide part 110 is formed in the first shaping coupler. 131 and a plurality of optical waveguides constituting the grating portion 130 and the optical waveguide having a single wavelength through the second shaping coupler 133, respectively, to proceed to the output waveguide portion 150. Thus, it is output through the output port 151 provided at the end of the output waveguide portion 150.

In this case, the input port 111 and the output port 151 are disposed on the same surface. This minimizes the planar optical waveguide device 100 module by unifying the optical fiber block 200 coupled to the input port 111 and the output port 151, and at the same time the time required to align the optical fiber block 200. To shorten.

The optical fiber block 200 has a plurality of V-grooves for aligning the optical fibers corresponding to the input port 111 and the output port 151, align the optical fibers in the V-groove and then use an adhesive or the like. To fix it.

The planar optical waveguide device module is completed by coupling the input port 111 and the output port 151 of the planar optical waveguide device 100 and the ends of the optical fibers aligned with the optical fiber block 200 to each other.

However, the planar optical waveguide device in which the input port and the output port are disposed on the same plane is arranged to input a predetermined optical signal to the input port while aligning the optical fiber block to find a position where the optical signal intensity from the output port is maximum. When the position of the optical fiber block is adjusted, the optical coupling intensity between the output port of the optical fiber block and the input port of the planar optical waveguide device is changed. Therefore, the output is output to the optical fiber block through the planar optical waveguide device. The intensity of the optical signal is also changed. That is, under the same optical signal input condition, the position of the optical fiber block should be adjusted to maximize the output optical signal. In the process of adjusting the position of the optical fiber block, the optical signal input condition is changed, making it difficult to align the optical fiber block. have.

In order to solve the above problems, it is an object of the present invention to provide an alignment device of a planar optical waveguide device having an input port and an output port arranged on the same surface and at the same time easy alignment with the optical fiber block.

In order to achieve the above object, the present invention provides a planar optical waveguide device having an input port of an input waveguide portion and an output port of an output waveguide portion disposed on the same plane, and having a grating portion between the input waveguide portion and the output waveguide portion, An alignment device between an optical fiber block in which optical fibers corresponding to an input port and an output port of an element are aligned with a planar light guide and bonded to the planar optical waveguide device, the apparatus comprising: a dummy input port disposed on a surface different from the input port and an output port; ; One end is connected to the dummy input port, and the other end is connected to the grating portion, and has a dummy input waveguide for providing a path through which the optical signal input through the dummy input port travels.

1 is an enlarged perspective view illustrating a planar optical waveguide device module according to a conventional embodiment;

FIG. 2 is an enlarged plan view showing an alignment portion between the planar optical waveguide device and the optical fiber block shown in FIG. 1;

3 is an enlarged perspective view illustrating a planar optical waveguide device module according to an exemplary embodiment of the present invention;

4 is an enlarged plan view illustrating an alignment portion between the planar optical waveguide device and the optical fiber block shown in FIG. 3;

Description of the main parts of the drawing

300: planar optical waveguide device 400: optical fiber block

310: input waveguide part 311: input port

330: grid portion 350: output waveguide portion

351: output port 370: dummy input waveguide

371 dummy input port

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

3 is an enlarged perspective view of a planar optical waveguide device 300 module according to a preferred embodiment of the present invention, Figure 4 is an alignment portion between the planar optical waveguide device 300 and the optical fiber block 400 shown in FIG. It is a top view which expands and shows.

3 and 4, the planar optical waveguide device 300 module according to a preferred embodiment of the present invention is an optical fiber block bonded to the planar optical waveguide device 300 and the planar optical waveguide device 300 400).

The planar optical waveguide device 300 includes an input waveguide part 310, a dummy input waveguide 370, a grating part 330, and an output waveguide part 350. First and second shaped couplers 331, 333. In addition, glass top plates 391 and 393 may be attached to improve workability.

The planar optical waveguide device 300 configured as described above is coupled to an optical fiber block 400 in which an optical fiber 410 for inputting optical signals and a ribbon optical fiber 430 for outputting the optical signals are arranged.

The input waveguide part 310 includes an input port 311 provided at one side of the planar optical waveguide device 300 and an input waveguide extending from the input port 311 to the grating part 330. It provides a path through which an optical signal composed of a plurality of wavelengths input through the optical fiber 410 on the optical fiber block 400.

The optical signal passing through the input waveguide part 310 passes through the optical waveguides which are classified with the first shaped coupler 331 of the grating part 330 and constitute the grating part 330, and the second shaped coupler The signals are classified into optical signals having respective wavelengths through the 333 and proceed to the output waveguide part 350.

The output waveguide part 350 outputs optical signals having the respective wavelengths to the ribbon optical fiber 430 on the optical fiber block 400 through the output port 351. The output port 351 is disposed on the same surface as the input port 311.

The dummy input waveguide 370 is connected to the first shaping coupler 331 of the grating part 330 and extends to the dummy input port 371 provided on the other side of the planar optical waveguide device 300.

When the planar optical waveguide device 300 is aligned with the optical fiber block 400, a wideband optical signal is input to the dummy input port 371 and the output signal is monitored by the ribbon optical fiber 430 on the optical fiber block 400. In this case, the dummy input waveguide 370 provides a path through which a wideband optical signal travels. When the dummy input waveguide 370 is not present, the wideband optical signal is input through the input waveguide part 310 of the planar optical waveguide device 300 and the optical signal intensity is monitored at the output side of the ribbon optical fiber 430. While adjusting the position of the optical fiber block, when adjusting the position of the optical fiber block 400, the optical coupling between the input port 311 of the planar optical waveguide device 300 and the output port 411 of the optical fiber block 400 The reason is that it is difficult to properly align the planar optical waveguide device 300 and the optical fiber block 400 because the intensity varies and the optical signal input condition is changed.

Meanwhile, the optical fiber block 400 aligned with and coupled to the planar optical waveguide device 300 may include ports 411 and 431 corresponding to the input port 311 and the output port 351 of the planar optical waveguide device 300. ). The optical fiber block 400 is a block for supporting the optical fibers 410 and 430, and usually forms a V-groove in a silicon substrate or a quartz substrate to arrange the optical fiber and the ribbon optical fiber and is fixed using the adhesive 450.

According to the configuration as described above, the optical signal consisting of a plurality of wavelengths coming through the optical fiber 410 arranged in the optical fiber block 400 is passed through the input waveguide portion 310 of the planar optical waveguide device 300. Passing through the grating portion 330 including the first and second shaping coupler (331, 333) is separated into an optical signal of one wavelength, respectively, and transmitted to the ribbon optical fiber 430 through the output waveguide portion 350.

The process of aligning the planar optical waveguide device 300 and the optical fiber block 400 is as follows. First, the broadband light source is incident on the dummy input port 371 and the initial alignment is performed while measuring the intensity of the optical signal output from the ribbon optical fiber 430 aligned with the optical fiber block 400. At this time, there is no need for precise sorting since no optimized sorting is required. Next, precise alignment is performed while measuring the intensity of the optical signal output from the optical fibers at both edges of the ribbon optical fiber 430. At this time, alignment with the optical fiber block 400 is performed at the output side of the planar optical waveguide device 300, and at the same time, alignment with the optical fiber block 400 is performed at the input side of the planar optical waveguide device 300. Therefore, the planar optical waveguide device according to the present invention can maintain the same input condition when aligned with the optical fiber block, thereby facilitating alignment.

On the other hand, in the detailed description of the present invention has been described with respect to specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the scope of the present invention.

As described above, in the planar optical waveguide device module according to the present invention, the alignment device of the planar optical waveguide device module has an input port and an output port of the planar optical waveguide device arranged on the same surface, and are different from the input port and the output port. It further includes a dummy input waveguide extending from the dummy input port disposed on the surface, so that the optical fiber block alignment can be input through the dummy input port and aligned while monitoring the output of the broadband optical signal on the output side. It is easy and has the advantage of reducing the time required for the alignment process.

Claims (1)

An input port of an input waveguide part and an output port of an output waveguide part are disposed on the same plane, and include a planar optical waveguide device having a grating portion between the input waveguide part and the output waveguide part, and the planar optical waveguide device corresponds to an input port and an output port of the device. In the alignment device between the optical fiber block is aligned and bonded to the planar optical waveguide device, A dummy input port disposed on a surface different from the input port and output port; And a dummy input waveguide having one end connected to the dummy input port and the other end connected to the grating part, the dummy input waveguide providing a path through which the optical signal input through the dummy input port travels. Alignment device.