KR101227039B1 - Optical power monitoring module - Google Patents

Abstract

PURPOSE: An optical power monitoring module is provided to eliminate a process inserting a metallic mirror by receiving optical signals for monitoring through a tap coupler perpendicularly branched, thereby simplifying a manufacturing process. CONSTITUTION: An optical power monitoring module comprises a planar optical waveguide element(100), a thin film type flexible PCB(130), and a photodiode array(140). The planar optical waveguide element comprises a substrate, an optical circuit, and a tap coupler. The thin film type flexible PCB is connected to a surface of one side of the planar optical waveguide element and arranged in a direction facing to a core layer branched by the tap coupler. The thin film type flexible PCB forms an opening where some of optical signals pass through the inclined side of the planar optical waveguide element. The photodiode array is fixed to opening of the thin film type flexible PCB and receives the optical signals branched from the tap coupler through the opening.

Description

Optical power monitoring module {OPTICAL POWER MONITORING MODULE}

The present invention relates to an optical power monitoring module, and more particularly, an optical power monitoring module that can simplify a manufacturing process by removing a process of inserting a metallic mirror by receiving a monitoring optical signal through a vertically branched tap coupler. It is about.

In the optical communication field, a flat panel optical waveguide device (PLC: Planar) is used for multiplexing (multiplexing) optical signals of various wavelengths, separating (demultiplexing) the multiplexed optical signals into optical signals of individual wavelengths, or evenly distributing optical power. Lightwave Circuits, such as Arrayed Waveguide Grating (AWG), Optical Power Splitter (Optical Power Splitter).

In general, an arrayed waveguide grating element (hereinafter referred to as an AWG element), which is a planar optical waveguide element (hereinafter referred to as a 'PLC element'), has a plurality of multiplexed optical signals inputted through a single input optical waveguide. The demultiplexing function outputs the output optical waveguide or the multiplexing function outputs each of a plurality of different wavelength signals inputted from the plurality of input optical waveguides into a single output optical waveguide.

The device for controlling the optical signal as described above is called a passive device, and is mainly manufactured using a silica medium having a different refractive index on a silicon substrate. The AWG device stacks a cladding layer and a core layer on a substrate, and then etches the core layer through a lithography process and a dry etching process to advance an optical signal along a patterned core in various forms. It is generally manufactured by forming a furnace and forming a cladding layer on the substrate on which the patterned core is formed.

On the other hand, when integrating such PLC devices such as AWG, multi-port variable optical attenuator (VOA), optical power divider, and the like to form an optical sub system for processing optical signals, a plurality of inputs It is desirable to monitor and adjust the optical signal power input and output from each input port or each output port of the PLC device having a port or a plurality of output ports.

At this time, in order to monitor the optical signal of each input and output port, the tap coupler is installed in the input and output optical waveguide connected to a plurality of input ports or output ports, branching the optical signal to the other optical waveguide made by using the tap coupler, branching It is necessary to monitor the power of the optical signal, which is a photodiode as an active element.

In this case, the photodiode used is a representative active element and converts an optical signal into an electrical signal. Other active devices include laser diodes that convert electrical signals into optical signals. In order to handle 1310 / 1550nm wavelength optical signals, which are mainly used in optical communication, photovoltaic devices or photoelectric effects are stacked on InP substrates to form pn junction layers by stacking InGaAs materials with different composition ratios. To fabricate an active element that can be replaced with or convert an electrical signal into an optical signal.

In order to use such active elements in combination with passive elements, since they are composed of different mediums, passive elements and active elements cannot be manufactured simultaneously in the same process on one substrate, and each completed element is aligned through each process. And attach. This coupling of active elements integrated in different media onto passive elements is called hybrid integration.

In the conventional hybrid integrated technology, a narrow and inclined groove is formed to cut off the planar optical waveguide constituting the PLC element, and a reflection filter is inserted to reflect the optical signal traveling through the planar optical waveguide outside the core of the planar optical waveguide to enter the photodiode receiving region. The method of making is disclosed. In this case, in order to attach the active element to the passive element, a silicon platform must be formed on the substrate of the passive element, the planar optical waveguide and the active region of the active element must be precisely aligned, and flip chip bonded. do.

1A and 1B illustrate a coupling structure of a planar optical waveguide device 40 and a photodiode device 50 that is an active device constructed according to the prior art.

First of all, the PLC device module that can be used in practical field is the input optical fiber array with the optical connector as the incident port and the output optical fiber array with the optical connector as the exit port, and the optical signal is adjusted by intervening between them. , Harmonics, light intensity adjustment, etc.). In addition, in order to convert an optical signal traveling through a planar optical waveguide into an electrical signal, a photodiode as an active element and an electrical circuit connecting the same must be further configured. At this time, the photodiode is an element that outputs a current or voltage that is an electrical signal proportional to the received light intensity.

In this case, conventionally, first, a trench 35 having an oblique angle in a depth direction breaking the core 12 of the planar optical waveguide is cut at the end of the output optical waveguide, and a reflection mirror 11 having a constant reflectance is formed therein. By inserting the light signal traveling through the core 12 of the planar optical waveguide, the optical signal is reflected at a predetermined angle to receive the reflected light 17 in the light receiving region 51 of the photodiode placed at the end of the path of the reflected light. In this case, part or all of the light may be received by the photodiode 50 by adjusting the reflectance of the reflecting mirror 11 having a predetermined reflectance. In addition, the groove 35 formed at the end portion of the output optical waveguide has a very clean cutting surface to prevent scattering of light, and the width of the groove 35 is made narrow so as to substantially match the reflection mirror 11 to be inserted. The thin reflective mirror 11 can be accurately placed without skewing so that the reflected angle can be kept constant. In addition, it is necessary to control the transmittance of the reflective mirror 11 and make the thickness smaller than several tens of micrometers so that the optical signal can be transmitted without loss to the continuous optical waveguide behind the reflective mirror 11.

In addition, when the groove 35 is formed, the angle of the groove 35 must be exactly coincident so that the reflected optical signal does not deviate from the light receiving region 51 of the photodiode.

However, in the conventional optical power measurement module for a planar optical waveguide device, since a filter is disposed in a groove formed on the optical path, the manufacturing process of the planar optical waveguide device and the manufacturing process of the active device must be performed separately. In addition, even if integrated directly on the flat waveguide device, it must be integrated to avoid the grooves or filters, and because the electric circuit must be implemented separately to integrate individually, bulk processing is difficult, which is quite disadvantageous in terms of mass production. In addition, the increased fabrication cost for the groove implementation process and the filter, and the difficulty of precise alignment, are disadvantageous in terms of reproducibility and reliability by heterogeneous materials different from silicone / silica materials.

In particular, the method using the groove and the filter is difficult to be applied to each other in the process before the passive element process and the active element process are completely implemented in the chip state, and even if the active element is directly integrated on the planar optical waveguide element, Since it is necessary to integrate the filter, it is inevitable to bulk production due to the separate implementation of the electric circuit separately, which is quite disadvantageous in terms of mass production, increasing the manufacturing cost of the home realization process and the filter, and precise alignment. Because of the difficulty, there are disadvantageous problems in terms of reproducibility and reliability due to the insertion of heterogeneous materials other than the silicone / silica material.

In addition, since the flip chip process of integrating the photodiode requires a high temperature, the deformation of the polymer material may cause heat deformation, and even if a heat-independent filter is applied, the alignment may be caused by deformation of the adhesive material. Since it can not be exposed to heat for a long time like a bulk process, such as a state of disorder, it is difficult to mix the process of the passive element and the active element, and the passive element and the active element of each chip type completed through each process There is a problem to align and attach.

FIG. 2 is yet another conventional technique, in order to solve the problem according to FIG. 1, a structure in which an active element is directly formed on an upper side of a plate type optical waveguide device is disclosed.

In the related art according to FIG. 2, the planar optical waveguide device 60, the active device 64, and the output optical fiber array 70 are implemented. The flat optical waveguide device 60 is formed of a laminated structure of a substrate 61, a lower clad layer 62a, a core layer 62b, and an upper clad layer 62c, and is disposed on an upper side of the substrate. ) Was formed, and the electric circuit 64a was directly laminated on the upper clad layer 62c of the plate optical waveguide device, and the photodiode 64b was fixed to the light receiving opening region of the electric circuit 64a.

The output optical fiber array 70 includes a support substrate 71 disposed on the light output side of the planar optical waveguide element 60 and light provided on the support substrate 71 and outputted from an output end of the optical circuit 62. Reflecting surface 66 is provided on the optical fiber 76 receiving the signal, and the support substrate 71 is reflected to the photodiode 64b of the active element 64 to reflect the optical signal output from the output terminal of the optical circuit Configure to have.

Here, a plurality of V-shaped grooves (not shown) are formed in the support substrate 71 in the output optical fiber array 70, and the optical fiber 76 and the metal wire 74 are selectively formed in the plurality of V-shaped grooves (not shown). Placed. At this time, since the radius formed in the V-shaped groove was about 127 micrometers, the metal wire 74 having a radius of less than 100 micrometers had to be inserted.

In this case, since a metal having good reflectance must be used and a very thin metal wire must be inserted one by one, there are many problems in the manufacturing process to insert the metal wire. Even if the metal wire is bent in the process of inserting the metal wire, there is a problem that there is no method that can be directly confirmed in the manufacturing process.

3 is a diagram illustrating a tab coupler of a planar optical waveguide device according to the related art.

As shown in FIG. 3, the planar optical waveguide device 90 implements the tab coupler 92, and the main port 92a is connected to the optical fiber 96 through the output optical fiber array 95.

The optical signal of the planar optical waveguide device 90 progresses along the optical circuit, and partly branches to the tap port 92b while passing through the tap coupler 92. At this time, the main port 92a transmits an optical signal to the optical fiber 96 of the output optical fiber array 95, and a part of the optical signal branched to the tap port 92b is an active element through the reflective mirror metal wire 97. (Not shown).

As described above, in the related art, since the main port 92a used for communication and the tap port 92b used for monitoring are configured in parallel, the optical fiber 96 which passes light through the optical fiber array as described above and There was a problem in that a mirror of the metal mirror 97 for reflecting mirrors reflecting light must be inserted.

Therefore, the conventional techniques have a high defect rate in the process of making the output side optical fiber array, and it takes a long time to insert a metal wire, there is a problem that the mass productivity is greatly reduced.

In addition, although there have been many researches and concerns for a long time about the method for integrating an optical signal to be directly received by a photodiode array in an optical waveguide, due to the structural characteristics of the passive element and the optical fiber connected, optical power The monitoring module has only been considered a method of receiving the optical signal indirectly through a tap coupler or a filter, but these methods are not only structurally complicated but also have various problems as pointed out above.

Therefore, in recent years, the optical power monitoring module does not use a reflection filter or a mirror, or requires a technology capable of directly integrating a photodiode array in a planar optical waveguide device.

The present invention arranges the tab port of the tap coupler so that it can be received by the photodiode array vertically in the optical waveguide, so that the optical signal can be directly transmitted without using an optical fiber array or a filter in which a metal reflection mirror of a complicated structure or process is inserted. It is possible to receive the light to solve the conventional problems, through which it is possible to implement a very simple optical power monitoring module.

SUMMARY OF THE INVENTION In order to solve the conventional problem, an object of the present invention is to provide an optical power monitoring module that can simplify the manufacturing process by eliminating the process of inserting a metallic mirror by receiving a monitoring optical signal through a vertically branched tap coupler. I would like to.

In addition, another object of the present invention is to provide an optical power monitoring module capable of integrating a photodiode array in a planar optical waveguide device by using a flexible flexible thin flexible PCB. .

In addition, another object of the present invention is to provide an optical power monitoring module that can improve the light receiving rate by placing a photodiode array on the optical waveguide to directly receive the optical signal.

In addition, another object of the present invention is to provide an optical power monitoring module that can simplify the manufacturing process by integrating a photodiode array in a planar optical waveguide device using a thin-film flexible printed circuit board.

In addition, another object of the present invention is to provide an optical power monitoring module that can simplify the manufacturing process by simplifying the process of filter insertion and optical coating that requires a high degree of difficulty slit process.

In addition, another object of the present invention is to provide an optical power monitoring module that can simplify the manufacturing process and reduce the manufacturing cost by eliminating the need to manufacture a special optical fiber array, such as a conventional output optical fiber array.

In addition, another object of the present invention is to provide the optical signal from the core layer to the photodiode array through the air layer or vacuum state or the specific gas of the opening formed in the thin-film flexible printed circuit board, the medium having a higher refractive index than conventional air Compared to the structure received through the through to reduce the light scattering effect to provide an optical power monitoring module that can minimize the effect between adjacent channels due to noise.

In addition, another object of the present invention is to provide an optical signal from the core layer to the photodiode array through an air layer or a vacuum state or a specific gas of the opening formed in the thin-film flexible printed circuit board, thereby maximizing the light receiving sensitivity We want to provide a monitoring module.

In addition, another object of the present invention is to form a plurality of openings formed in the thin-film flexible printed circuit board and provide the optical signal by each core layer to the light receiving portion of the photodiode array to be mapped, thereby minimizing interference between adjacent channels. An optical power monitoring module is provided.

The optical power monitoring module of the present invention for achieving the above objects includes a substrate, an optical circuit disposed on the upper side of the substrate including a core layer stacked between the lower cladding layer and the upper cladding layer, and an optical signal of the core layer. Flat optical waveguide device having a structure comprising a tab coupler for branching, connected to one side of the flat optical waveguide device, disposed in a direction facing the core layer branched by the tab coupler, the tap coupler A thin flexible PCB forming an opening through which the branched optical signal passes, and fixed to the opening of the thin flexible printed circuit board, the optical signal branched from the tap coupler through the opening It comprises a receiving photo diode array.

In addition, the tap coupler is characterized in that the branching direction of the optical signal in the vertical direction.

In addition, the interval between the core layers of the section in which the tab coupler is formed is characterized in that formed so as to be spaced apart from the interval between the input and output optical fibers.

An optical power monitoring module of the present invention for achieving the above objects includes an optical circuit disposed on an upper side of the substrate including a substrate, one or more core layers stacked between the lower clad layer and the upper clad layer; A thin film type flexible printed circuit board having a planar optical waveguide device having a structure including a cover glass disposed on an upper side thereof, and connected to the flat plate optical waveguide device and forming a plurality of openings through which the optical signal transmitted from the core layer passes. (Thin Flexible PCB) and a photodiode array fixed to the opening of the thin-film flexible printed circuit board, the plurality of light receiving units receiving the optical signal through the plurality of openings.

In addition, a plurality of the openings may be formed as many as the number of core layers, and the core layers and the light receiving units may be formed to match both ends of the plurality of openings.

In addition, the plate-type optical waveguide device is characterized in that it comprises a tab coupler for vertically splitting the optical signal of the core layer.

In addition, the planar optical waveguide device may be formed by grinding a side surface of the planar optical waveguide device on which the thin film type flexible printed circuit board and the photodiode array are disposed at a predetermined angle to minimize reflection loss.

The optical power monitoring module of the present invention for achieving the above objects includes a substrate, an optical circuit disposed on the upper side of the substrate including a core layer stacked between the lower cladding layer and the upper cladding layer, and an optical signal of the core layer. Is composed of a flat panel optical waveguide device and a metal thin film layer having a structure including a tab coupler for branching in a vertical direction, and is directly stacked on the upper clad layer of the flat optical waveguide device in a lift-off manner. An electrical circuit and a photodiode array connected to the electrical circuit and fixed to a flip chip bonding method or eutectic bonding on an upper side of the flat optical waveguide device, wherein the flat optical The waveguide element forms a reflecting surface that reflects the optical signal branched from the tap coupler to the photodiode array, and the reflecting surface is It is ground to a predetermined angle, characterized in that to form a HR (High Reflection) coating.

As described above, the present invention provides an optical power monitoring module that can simplify the manufacturing process by eliminating the process of inserting the metallic mirror by receiving the monitoring optical signal through the vertically branched tap coupler.

In addition, the optical power monitoring module of the present invention provides an optical power monitoring module capable of integrating a photodiode array in a flat optical waveguide device by using a flexible thin film flexible flexible printed circuit board (Tin Flexible PCB). do.

In addition, the optical power monitoring module of the present invention provides an environment in which the light reception rate can be improved by arranging a photodiode array on an optical waveguide to directly receive an optical signal.

In addition, the optical power monitoring module of the present invention provides an environment that can simplify the manufacturing process by integrating a photodiode array in a planar optical waveguide device using a thin-film flexible printed circuit board.

In addition, the optical power monitoring module of the present invention provides an environment capable of simplifying the manufacturing process by simplifying the process of filter insertion and optical coating, which requires a high difficulty slit process.

In addition, the optical power monitoring module of the present invention eliminates the need to manufacture a special optical fiber array such as a conventional output optical fiber array, thereby providing an environment that can simplify the manufacturing process and reduce the manufacturing cost.

In addition, the optical power monitoring module of the present invention provides the optical signal from the core layer to the photodiode array through an air layer or a vacuum state or a specific gas of the opening formed in the thin-film flexible printed circuit board, so that the refractive index is higher than that of conventional air. Compared to a structure that receives light through a high medium, the light scattering effect is reduced to provide an environment that can minimize the influence between adjacent channels due to noise.

In addition, the optical power monitoring module of the present invention can maximize the light receiving sensitivity by providing the optical signal from the core layer to the photodiode array through an air layer or a vacuum state or a specific gas of the opening formed in the thin-film flexible printed circuit board. Provide an environment.

In addition, the optical power monitoring module of the present invention forms a plurality of openings formed in the thin-film flexible printed circuit board and provides optical signals by the respective core layers to the light receiving units of the photodiode arrays to be mapped, thereby minimizing interference between adjacent channels. Provide an environment for doing this.

1A and 1B show a coupling structure of a planar optical waveguide device and a photodiode device, which is an active device, constructed according to the prior art.
FIG. 2 discloses a structure in which an active element is directly formed on an upper side of a planar optical waveguide device according to another conventional technology.
3 is a diagram illustrating a tab coupler of a planar optical waveguide device according to the related art.
4 is a perspective view of an optical power monitoring module using a vertically branched tap coupler according to a first embodiment of the present invention.
5 is a plan view of an optical circuit showing the vertically branched tab coupler according to FIG. 4.
6 is a plan view of a thin-film flexible printed circuit board according to the present invention.
7 is a front view of a photodiode array according to the present invention.
8 is a plan view of the optical power monitoring module according to FIG. 4 seen from above.
9 is a plan view of a thin film type flexible printed circuit board having a plurality of openings according to a second embodiment of the present invention.
FIG. 10 is a plan view of a photodiode array coupled to the thin film type flexible printed circuit board of FIG. 9.
FIG. 11 is a perspective view of the thin film flexible printed circuit board of FIG. 9 coupled to the flat optical waveguide device of FIG. 4.
FIG. 12 is a cross-sectional view of the optical power monitoring module of FIG. 11 taken along the line aa ′.
13 is a perspective view of an optical power monitoring module using a tab coupler vertically branched according to the third embodiment of the present invention.
14 is a front view of the optical power monitoring module according to FIG. 13.
15 is a side view of the optical power monitoring module according to FIG. 13.
16 is a plan view of the optical power monitoring module according to FIG. 13.

The embodiments of the present invention can be modified into various forms and the scope of the present invention should not be interpreted as being limited by the embodiments described below. The present embodiments are provided to enable those skilled in the art to more fully understand the present invention. Therefore, the shapes and the like of the components in the drawings are exaggerated in order to emphasize a clearer explanation.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 4 to 16.

4 is a perspective view of an optical power monitoring module using a vertically branched tap coupler according to a first embodiment of the present invention.

Optical power monitoring module using a vertically branched tap coupler of the present invention according to Figure 4 is a planar optical waveguide device 100 (PLC: Planar Lightwave Circuit), a thin-film flexible printed circuit board 130 (Thin Flexible PCB) And a photodiode array 140.

The planar optical waveguide device 100 includes a substrate (not shown), an optical circuit (not shown), and a cover glass (not shown), and the optical circuit includes a lower clad layer (not shown) and an upper clad layer (not shown). ) One or more core layers 102 stacked between them.

Then, the optical signal provided from the input side optical fiber array 110 disposed at the optical input side end of the flat optical waveguide element 100 is input to the core layers 102 of the optical circuit formed on the substrate.

The planar optical waveguide device 100 vertically branches a part of the optical signal provided from the input side optical signal array 110 through the tab coupler 104 vertically branched.

Here, the optical signal of the core layer 102a vertically branched through the tab coupler 104 is transmitted to the light receiving portion of the photodiode array 140 through the opening 132 of the thin film type flexible printed circuit board 130. . The remaining non-branched optical signal is transmitted to the optical fiber of the output side optical fiber array 120.

In particular, the optical power monitoring module of the present invention directly receives the monitoring optical signal from the side of the flat optical waveguide device 100 through the tab coupler 104 vertically branched, thereby providing a metallic mirror as in the prior art. Eliminating the process of inserting has the effect of simplifying the manufacturing process. In addition, the present invention eliminates the need to manufacture a special optical fiber array such as a conventional output side optical fiber array, thereby simplifying the manufacturing process and reducing the manufacturing cost.

In addition, the present invention polishes the side surface of the planar optical waveguide device 100 on which the thin film type flexible printed circuit board 130 and the photodiode array 140 are disposed at a predetermined angle so as to minimize return loss. Can be formed.

Here, the side surface of the planar optical waveguide device 100 may be polished to about 8 degrees according to an embodiment of the present invention to minimize the reflection loss of the optical signal provided to the light receiving portion of the photodiode array 140.

The thin-film flexible printed circuit board 130 includes an opening 132 and one or more electrodes 134, and an electric circuit is patterned. The thin film type flexible printed circuit board 130 is disposed on one side of the flat optical waveguide device 100.

Here, the branched core layer 102a and the following photodiode array 140 of the planar optical waveguide device 100 are disposed at both ends of the opening 132, and the optical signal from the branched core layer 102a is opened. Passed through 132 to the photodiode array 140.

In particular, the opening 132 becomes an empty space, and the optical signal from the core layer 126b will pass directly through the empty space to the light receiving portion 142 of the photodiode array 140.

Here, the opening 132 may be implemented in a vacuum state according to an embodiment of the present invention. In addition, the opening 132 may be formed as an air layer according to another embodiment of the present invention, or may be formed by inserting specific gases to more efficiently transmit the optical signal, the configuration of the opening 132 Various modifications may be made to minimize the scattering effect and maximize the light receiving sensitivity by the photodiode array 140. For example, the opening 132 may form the specific gas with cesium gas.

The photodiode array 140 is disposed opposite to the thin film type flexible printed circuit board 130 disposed on the planar optical waveguide device 100, and is disposed in the opening 132 of the thin film type flexible printed circuit board 130. It is fixed by flip chip bonding method or eutectic bonding.

And a light receiving unit 142 in which one or more photodiodes of the photodiode array 140 are arranged in parallel, wherein the light receiving unit 142 is provided from the core layer 102a of the planar optical waveguide device 100. The optical signal is transmitted through the opening 132 of the thin film flexible printed circuit board 130.

Therefore, the optical power monitoring module according to the present invention has the effect of improving the light reception rate by directly receiving an optical signal by arranging the photodiode array 140 on the optical waveguide vertically branched through the tap coupler 104. To provide.

In addition, the optical power monitoring module of the present invention provides the optical signal from the branched core layer 102a to the photodiode array 140 through the air layer of the opening 132 formed in the thin film type flexible printed circuit board 130. In addition, the light scattering effect can be reduced to minimize the influence between adjacent channels due to noise, and the light receiving sensitivity can be maximized.

5 is a plan view of an optical circuit showing the vertically branched tab coupler according to FIG. 4.

The tap coupler 104 is embodied perpendicularly to the traveling direction of the optical signal, and branches the optical signal by the input side optical fiber array 110 vertically.

In addition, the core layer 102c of the portion where the tab coupler 104 is disposed according to an embodiment of the present invention is designed to be spaced farther than a distance between the core layer 102b on the input side and the core layer 102d on the output side of the device. It is characterized by being. This is to minimize bending loss that may occur when the tap coupler 104 is designed at a right angle.

6 is a plan view of a thin-film flexible printed circuit board according to the present invention.

6 (a) and 6 (b), the thin-film flexible printed circuit board 130 includes an opening 132, an electrical circuit (not shown) patterned from the opening 132, and an electrical circuit. A plurality of connected electrodes 134 are included. Here, the thickness of the thin-film flexible printed circuit board 130 may be formed from 0.08mm to 0.1mm, it is implemented to bend freely. In addition, the electric circuit (not shown) may be made of gold (Au) material.

Particularly, as shown in FIG. 6 (b), the core layer 102a of the flat optical waveguide device 100 and the light receiving portion 142 of the photodiode array may be more precisely aligned when the optical power monitoring module of the present invention is manufactured. In order to do this, the opening 132 may be formed at an edge of one side of the thin film flexible printed circuit board 130.

Accordingly, the present invention can simplify the manufacturing process and significantly lower the manufacturing cost by eliminating the electrode patterning process on the substrate of the conventional flat waveguide device using the thin film type flexible printed circuit board 130 on which the electrode 134 is patterned. Will be.

7 is a front view of a photodiode array according to the present invention.

Referring to FIG. 7, eight channels of photodiodes are arranged as an integrated module according to an embodiment of the present invention. Each photodiode includes a cathode (not shown), a light receiving unit 142, and an anode (not shown). ).

Here, in the light receiving unit 142, the optical signal from the branched core layer 102a is directly transmitted through the air layer of the opening 132. The number of photodiodes aligned with the photodiode array 140 may vary depending on the number of branched core layers 102a.

8 is a plan view of the optical power monitoring module according to FIG. 4 seen from above.

In the optical power monitoring module according to the first embodiment of the present invention, the thin film type flexible printed circuit board 130 and the photodiode array 140 are disposed on the left side of the flat optical waveguide device 100.

 The planar optical waveguide device 100 includes a tab coupler 104 that branches the core layer 102 at right angles. At this time, the tap coupler 104 branches the optical signal from the input side optical fiber array 110 at right angles. In addition, the core layer 102 of the portion where the tap coupler 104 is disposed is farther apart than the gap between the core layers disposed in the input side optical fiber array 110 and the output side optical fiber array 120.

Here, the optical signal of the input side optical fiber array 110 is transmitted to the optical fiber of the output side optical fiber array 120 via the planar optical waveguide device 100.

A portion of the optical signal branched through the tab coupler 104 is transferred to the photodiode array 140 through the thin film type flexible printed circuit board 130 along the branched core layer 102a.

Accordingly, the present invention can simplify the manufacturing process by eliminating the process of inserting the metallic mirror by receiving the monitoring optical signal through the vertically branched tap coupler 104, a special optical fiber array such as a conventional output optical fiber array There is no need to make it.

In addition, the present invention can directly receive the optical signal by arranging the photodiode array 140 on the vertically branched core layer (102a), thereby providing an optical power monitoring module that can improve the light reception rate Will be provided.

9 is a plan view of a thin film type flexible printed circuit board having a plurality of openings according to a second embodiment of the present invention.

Referring to FIG. 9, the thin film type flexible printed circuit board 230 according to the second exemplary embodiment includes openings 232 spaced apart from each other.

Here, the plurality of openings 232 are formed as many as the number of light receiving portions of the core layer and the photodiode array of the planar optical waveguide device. This is for arranging the core layer of the planar optical waveguide device and the light receiving portions of the photodiode array to be mapped one-to-one at both ends of each opening 232.

FIG. 10 is a plan view of a photodiode array coupled to the thin film type flexible printed circuit board of FIG. 9.

Referring to FIG. 10, the active diode is formed by fixing the photodiode array 240 to the opening 232 of the thin film flexible printed circuit board 230 by flip chip bonding or common bonding.

Here, each of the openings 232 may be disposed so that the light receiving units of the photodiode array 240 correspond one-to-one. This is to transmit the optical signals of the core layer to the light receiving units of the photodiode array through the respective openings, so that the respective optical signals are provided without interference between adjacent channels.

FIG. 11 is a perspective view of the thin-film flexible printed circuit board of FIG. 9 coupled to the flat optical waveguide device of FIG. 4, and FIG. 12 is a cross-sectional view of the optical power monitoring module of FIG. 11 taken along line aa ′. It is a cross section.

11 and 12, the thin-film flexible printed circuit board 230 and the photodiode array 240 are disposed on one side of the planar optical waveguide device 200 and are branched by the tap coupler 204. It is disposed on the side opposite to the core layer 202a.

The branched core layer 202a of the planar optical waveguide device 200 and the light receiving unit 242 of the photodiode array 240 are formed at both ends of the plurality of openings 232 formed in the thin film type flexible printed circuit board 230. Are respectively opposed to each other.

Therefore, a plurality of optical signals by each branched core layer 202a are provided to the light receiving units 242 of the photodiode array 240 through the openings 232 without interference between adjacent channels.

FIG. 13 is a perspective view of an optical power monitoring module using a vertically branched tap coupler according to a third embodiment of the present invention, FIG. 14 is a front view of the optical power monitoring module according to FIG. 13, and FIG. One side view of the optical power monitoring module.

In the optical power monitoring module of FIG. 13, the photodiode array 330 is disposed on the flat optical waveguide device 300, and the electrical circuit 306 connected to the photodiode array 330 is stacked. . In addition, a tab coupler 304 for dividing the optical signal of the core layer in the vertical direction is included in the planar optical waveguide device 300.

The electric circuit 306 may be formed of a metal thin film layer and may be directly stacked in a lift-off manner on the upper clad layer of the flat optical waveguide device 300 to form an open area for receiving light.

The photodiode array 330 is connected to the electric circuit 306 and is fixed to the upper side of the flat optical waveguide device 300 by flip chip bonding or eutectic bonding. .

In addition, a reflecting surface 308 is formed on one side of the flat optical waveguide device 300 to reflect the optical signal branched from the tap coupler 304 to the photodiode array 330.

At this time, the reflective surface 308 is polished at a predetermined angle, characterized in that to form a high-reflection mirror facet coating (hereinafter referred to as "HR coating").

Here, a part of the optical signal of the input side optical fiber array 310 is branched by the tap coupler 304, and the rest is transmitted to the output side optical fiber array 330.

Thus, referring to FIG. 15, the optical signal of the core layer 302a vertically branched by the tap coupler 304 is reflected by the reflecting surface 308 and transmitted to the photodiode array 330. The remaining non-branched optical signal is transmitted to the optical fiber of the output optical fiber array 320 via the planar optical waveguide device 300.

16 is a plan view of the optical power monitoring module according to FIG. 13.

Referring to FIG. 16, the optical power monitoring module according to the third embodiment of the present invention shows that the photodiode array 330 is disposed on the flat optical waveguide device 300 and the electrical circuits are stacked.

 The tab coupler 304 which branches the core layer 302 at right angles branches the optical signal from the input side optical fiber array 310 at right angles in the flat optical waveguide element 300. In addition, the core layer 302 of the portion where the tap coupler 304 is disposed is farther away from the gap between the core layers disposed in the input side optical fiber array 310 and the output side optical fiber array 320.

Here, the optical signal of the input side optical fiber array 310 is transmitted to the optical fiber of the output side optical fiber array 320 via the planar optical waveguide device 300. A portion of the optical signal branched through the tap coupler 304 is reflected by the reflective surface 308 and transmitted to the photodiode array 330.

Accordingly, the present invention splits the optical signal vertically through the tab coupler 104 and receives the monitoring optical signal through the reflective surface 308 formed on one side of the flat optical waveguide device 300, thereby providing a metallic mirror. Eliminating the insertion process can simplify the manufacturing process, eliminating the need to fabricate special fiber arrays such as conventional output fiber arrays.

In the above, the configuration and operation of the optical power monitoring module according to the present invention is shown in accordance with the detailed description and drawings, but this is merely described by way of example, and various changes and modifications within the scope without departing from the technical spirit of the present invention. This is possible.

100,200,300: flat waveguide device, 102,202,302: core layer,
102a, 202a, 302a: branched core layer, 104, 204, 304: tab coupler,
110,210,310: input side optical fiber array, 120,220,320: output side optical fiber array,
130, 230: thin-film flexible printed circuit board, 132, 232: opening, 134, 306: electrode
140,240,330: photodiode array, 142: light receiving portion, 308: reflective surface

Claims (8)

A planar light having a structure including a substrate, an optical circuit disposed above the substrate including a core layer stacked between the lower clad layer and the upper clad layer, and a tab coupler for splitting the optical signal of the core layer. Waveguide elements;
A thin film type flexible printed circuit board connected to one side of the flat optical waveguide device and disposed in a direction opposite to the core layer branched by the tab coupler and forming an opening through which an optical signal branched from the tab coupler passes. Thin Flexible PCB); And
A photodiode array fixed to the opening of the thin-film flexible printed circuit board and receiving an optical signal branched from the tap coupler through the opening;
Optical power monitoring module comprising a. The method of claim 1,
The tap coupler is an optical power monitoring module, characterized in that for branching the traveling direction of the optical signal in the vertical direction. The method of claim 2,
The interval of the core layer of the section where the tap coupler is formed is an optical power monitoring module, characterized in that formed to be spaced farther apart than the interval of the input and output optical fibers. A flat plate comprising a substrate, an optical circuit disposed above the substrate including one or more core layers stacked between the lower clad layer and the upper clad layer, and a cover glass disposed above the optical circuit. Optical waveguide elements;
A thin flexible PCB connected to the flat optical waveguide device and forming a plurality of openings through which the optical signal transmitted from the core layer passes; And
A photodiode array fixed to the opening of the thin-film flexible printed circuit board, the photodiode receiving the optical signal through a plurality of the openings;
Optical power monitoring module comprising a. 5. The method of claim 4,
The plurality of openings are formed as many as the number of core layers, the optical power monitoring module, characterized in that the core layer and the light receiving unit is formed so as to match both ends of the plurality of openings. 5. The method of claim 4,
The flat optical waveguide device includes a tab coupler that vertically splits an optical signal of the core layer. The method according to claim 1 or 4,
The planar optical waveguide device is formed by polishing a side surface of the planar optical waveguide device on which a thin film type flexible printed circuit board and a photodiode array are disposed at a predetermined angle so as to minimize reflection loss. . An optical circuit disposed above the substrate, including a substrate, a core layer stacked between the lower clad layer and the upper clad layer, and a tab coupler for splitting the optical signal of the core layer in a vertical direction. Flat waveguide elements;
An electric circuit formed of a metal thin film layer and directly stacked on the upper clad layer of the plate-type optical waveguide device in a lift-off manner; And
And a photodiode array connected to the electric circuit and fixed to a flip chip bonding method or an eutectic bonding on an upper side of the plate-type optical waveguide device.
The planar optical waveguide device forms a reflecting surface that reflects the optical signal branched from the tap coupler to the photodiode array, and the reflecting surface is polished at a predetermined angle and forms HR coating. Optical power monitoring module.

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