KR101236692B1 - Method for manufacturing wavelength selector, wavelength division optical splitter and method for manufacturing thereof using the splitter - Google Patents

Abstract

PURPOSE: A manufacturing method of a wavelength selection device, a wavelength division optical splitter using the same, and a manufacturing method thereof are provided to divide and output the optical signal of a specific wavelength without using AWG by arranging a wavelength selection part and a collimator. CONSTITUTION: A wavelength division optical splitter includes a wavelength selection part(100), a collimator(200), an optical splitter(300), and an optical fiber array(400). The wavelength selection part penetrates an optical signal of a previously set wavelength among input optical signals, reflects remaining optical signals, and selects the optical signal of a specific wavelength. The collimator progresses an optical signal penetrated from a wavelength selection part in parallel in a fixed direction. The optical splitter divides and outputs an optical signal inputted from a collimator into at least two optical signals. The optical fiber array is optically arranged in the output terminal of the optical splitter.

Description

Manufacturing method of wavelength selection device, wavelength split optical splitter using the same and manufacturing method thereof {METHOD FOR MANUFACTURING WAVELENGTH SELECTOR, WAVELENGTH DIVISION OPTICAL SPLITTER AND METHOD FOR MANUFACTURING THEREOF USING THE SPLITTER}

The present invention relates to a method for manufacturing a wavelength selection device and a wavelength splitting optical splitter using the same. It relates to an optical splitter.

With the advancement of the knowledge and information society, the amount of information transmission is increasing rapidly. Recently, with the spread of smart devices, the traffic of wireless Internet (mobile service), which requires communication speed of 100Mbps or more, has exploded. In order to meet the demand for information transmission, the demand for high integration and wide bandwidth devices required for high-speed communication networks is increasing, and the range and importance thereof are also increasing.

Accordingly, researches on photonic integrated circuits (PICs) have been actively conducted in recent years, and the manufacturing method of photonic integrated circuits (PICs) is mainly made of planar optical circuits. These optical integrated circuit devices connect and package optical fiber arrays to input / output portions of optical splitters and supply them to consumers.

In general, an optical splitter is a device that transmits two or more optical signals by dividing an input optical signal into a frequency range having selected characteristics, respectively. It also performs the function of recombining with the optical signal of.

1 is a perspective view of an optical splitter according to the prior art, wherein the optical splitter includes an input optical fiber block 11 to which an input optical fiber 10 is fixed, and an input optical waveguide core 21 optically aligned with the input optical fiber 10. And a planar lightwave circuit (PLC) substrate 20 having a plurality of output optical waveguide cores 22 branched from the input optical waveguide core 21, and output optical waveguide cores 22 of the PLC substrate 20. Each of the output optical fibers 31 optically aligned in the < RTI ID = 0.0 >) < / RTI >

However, in the conventional optical splitter described above, since the input optical fiber block 11, the PLC substrate 20, and the output optical fiber block 30 are separated from each other, each of them must be optically aligned. To optically align the input optical waveguide core 21 and the output optical waveguide cores 22 of the PLC substrate 20 with the input optical fiber 10 and the output optical fibers 31, respectively, x, y, z, xθ An expensive six-axis high-precision optical stage that can be aligned in the directions of, yθ, and zθ is required, and a considerable time is required for precise alignment in the six-axis direction.

In addition, the optical splitter may separate and output one input light into a plurality of optical powers and may not output a specific wavelength.

Moreover, AWG (Arrayed Waveguide Grating) optical splitters generally used in WDM optical communication are not suitable for mass production due to poor productivity, and also have difficulty in maintaining reliability in precision and expensive products.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, the general object of the present invention is to provide a wavelength selection device that can substantially compensate for the various problems caused by the limitations and disadvantages in the prior art. It is to provide a manufacturing method and a wavelength division optical splitter using the same.

Another object of the present invention is to provide a method of manufacturing a wavelength selection device capable of dividing and outputting an input optical signal into an optical signal having a desired wavelength without using a WDM device, and a wavelength division optical splitter using the same.

Another specific object of the present invention is to provide a method of manufacturing a wavelength selection device suitable for high integration, low cost and mass production, and a wavelength division optical splitter using the same.

To this end, a wavelength division optical splitter according to an embodiment of the present invention includes a wavelength selection unit for transmitting an optical signal having a predetermined wavelength among input optical signals and reflecting the remaining optical signals to selectively output an optical signal having a specific wavelength; A collimator for advancing the optical signal output from the wavelength selector in parallel in a predetermined direction; An optical splitter for splitting and outputting an optical signal input from the collimator into at least two optical signals; And an optical fiber array optically aligned to an output end of the optical splitter.

In one embodiment of the present invention, the wavelength selector includes a first optical fiber for transmitting an optical signal emitted from a light source, a pigtail into which an output end of the first optical fiber is inserted, and the pigtail at an output end of the first optical fiber; A dual collimator having any one of a GRIN lens and a C-lens connected to convert the input optical signal into parallel light and output an optical signal having a predetermined wavelength among the parallel light passing through the dual collimator, and the light having the remaining wavelength A thin film filter which totally reflects a signal, and an input terminal thereof is inserted into the pigtail, and a second optical fiber which transmits an optical signal reflected by the thin film filter to another node.

In one embodiment of the present invention, one end of the pigtail and one end of the GRIN lens or C-lens connecting to the one end of the pigtail may be formed to be inclined at a predetermined angle.

In one embodiment of the present invention, the collimator may be made of any one of a GRIN lens or C-lens.

In addition, the present invention is a method of manufacturing a wavelength selection device for transmitting an optical signal of a predetermined wavelength of the input optical signal and reflecting the remaining optical signal to output an optical signal of a specific wavelength, the output terminal of the first optical fiber and the second optical fiber Inserting and fixing the input end of the pigtail into one end of the pigtail; Connecting a thin film filter to one end of a GRIN lens or C-lens; Optically aligning the other end of the pigtail and the other end of the GRIN lens or C-lens so as to minimize insertion loss and then connecting the optically aligned; And inserting the connected pigtail and the GRIN lens or C-lens into a glass tube to fix the pigtail.

According to the wavelength division optical splitter according to the present invention, an expensive wavelength division multiplexing device such as AWG by arranging at the input terminal of the optical splitter a wavelength selection unit for transmitting an optical signal of a specific wavelength and a collimator for converting and outputting the input light into parallel light. It is possible to divide and output the optical signal of a specific wavelength without using.

In addition, according to the present invention, by integrating and integrating the wavelength selection device and the optical splitter, the packaging is easy and there is an advantage that mass production can be performed at low cost.

1 is a perspective view of an optical splitter according to the prior art.
2 is a perspective view of a wavelength division optical splitter according to an embodiment of the present invention.
3 is a cross-sectional view illustrating a configuration of an embodiment of the wavelength selector of FIG. 2.
4 is a view illustrating a manufacturing process of an embodiment of the wavelength selector of FIG. 2.
FIG. 5 is a diagram for describing an optical alignment process between the collimator and the splitter of FIG. 2.
6 and 7 are graphs of measurement of a transmission wavelength region and a reflection wavelength region of an optical signal passing through a wavelength division optical splitter according to an embodiment of the present invention.
8 is a view showing the product shape of the wavelength division optical splitter manufactured according to an embodiment of the present invention.

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, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the terms described below are defined in consideration of the functions of the present invention, and these may vary depending on the intention of the user, the operator, or the precedent. Therefore, the definition should be based on the contents throughout this specification.

2 is a perspective view of a wavelength division optical splitter according to an embodiment of the present invention.

Referring to FIG. 2, the wavelength division optical splitter according to the embodiment transmits an optical signal having a predetermined wavelength among input optical signals and reflects the remaining optical signals to select an optical signal having a specific wavelength; And a collimator 200 for advancing the optical signal transmitted from the wavelength selecting unit 100 in parallel in a predetermined direction, and an optical splitter for dividing and outputting the optical signal input from the collimator 200 into at least two optical signals. 300 and an optical fiber array 400 optically aligned to the output end of the optical splitter.

3 is a cross-sectional view illustrating a configuration of an embodiment of the wavelength selector of FIG. 2.

Referring to FIG. 3, the wavelength selector 100 includes a first optical fiber 110, a dual collimator 120, a thin film filter 130, and a second optical fiber 140.

The first optical fiber 110 transmits an optical signal having a predetermined wavelength emitted from a light emitter (not shown) such as a light source, for example, a laser light source, to the dual collimator 120.

The dual collimator 120 is a means for converting the optical signal transmitted through the first optical fiber 110 and the second optical fiber 140 into parallel light to output. The dual collimator 120 has a GRIN lens 122 therein, and an output end of the first optical fiber 110 and an input end of the second optical fiber 140 are respectively bonded to the GRIN lens 122. The optical signal emitted through the output terminal of the first optical fiber 110 is converted into parallel light by the GRIN lens 122, the specific wavelength, for example, λ ₁ optical signal is transmitted by the thin film filter 130, the rest The optical signal having the wavelength is reflected and incident through the input terminal of the second optical fiber 140.

The light traveling through the GRIN lens 122 optical fiber has a discrete energy distribution called mode. They propagate through a narrow fiber core of a few micrometers and, when released into free space, cause the beam to spread with a constant divergence angle due to strong diffraction characteristics. In general, an optical system that couples optical signals between input and output by suppressing diffraction characteristics is essential when manufacturing an optical component having a low insertion loss.

In addition, the GRIN lens 122 is about 1.6mm ~ 1.8mm in diameter, 4.52mm ~ 4.82mm in length is AR coating treatment to improve the reflection loss characteristics, it is preferable to polish the inclined cross section. Depending on the type of optical fiber, the maximum light receiving angle calculated from the N.A. value is about 7.9 °. Therefore, in the case of 8 ° face grinding, theoretically infinite reflection loss can be achieved, but GRIN lens can achieve high reflection loss of 60dB or more by combining with optical fiber polished at 8 ° angle in collimator packaging.

Alternatively, a C-lens may be used instead of the GRIN lens 122. C-lenses range from 1.6mm to 1.8mm in diameter, 4.32mm to 4.62mm in length, and can achieve relatively high return loss of more than 45dB with AR coating alone, and are cheaper than GRIN lenses.

The thin film filter 130 transmits the optical signal λ ₁ having a predetermined wavelength among the parallel light λ ₁ to λ _n passing through the GRIN lens 122 of the dual collimator 120, and the optical signal having the remaining wavelength is Total reflection. Here, the thin film filter 130 is an optical filter composed of a multi-layer thin film coating and transmits a single wavelength optical signal λ ₁ or various wavelengths of optical signals (for example, λ ₁ , λ ₂ , and λ ₃ ). And reflect the optical signal of the remaining wavelengths that are not transmitted. That is, it transmits optical signals of C-band (1530nm to 1565nm) and L-band (1565nm to 1625nm), which are mainly used for WDM optical communication, and O-band (1260nm to 1360nm) and E-band (1360nm to 1460nm), S-band (1460nm ~ 1530nm), U-band (1625nm ~ 1675nm) can be implemented to reflect the optical signal.

The second optical fiber 140 has an input terminal bonded to the GRIN lens 122 of the dual collimator 120 to transmit the optical signals λ ₂ to λ _n reflected by the thin film filter 130 to other nodes, and The optical signal of the wavelength transmitted from the node is emitted to the dual collimator (120).

The first and second optical fibers 110 and 140 are fixed to the pigtail glass tube 124 by an epoxy resin 126, the outside of the dual collimator 120 to mitigate the external shock without attenuating the input wavelength. It is surrounded by a glass tube (128).

Referring to FIG. 2 again, the collimator 200 is composed of a GRIN lens or a C-lens, and is optically aligned at the output terminal of the wavelength selector 100 so that the optical signal transmitted through the thin film filter 130 is constant. It runs in parallel in the direction.

The optical splitter 300 includes an input optical waveguide core 310 and at least two or more (8 in this embodiment) output optical waveguide cores branched from the input optical waveguide core 310, It is connected to the output terminal of the collimator 200 and outputs an optical signal input from the GRIN lens by dividing into eight optical signals. That is, the optical splitter 300 of the present embodiment is a device having an optical waveguide of 1x8, and may be implemented as an optical splitter having an optical waveguide multi-branched into 1xn as necessary.

The optical fiber array 400 is optically aligned at the output terminal of the optical splitter unit 300 and transmits an optical signal branched by the output optical waveguide cores 320.

Referring to the operation of the wavelength division optical splitter according to an embodiment of the present invention having the above-described configuration is as follows.

2 and 3 again, the optical signal of the multi-wavelengths λ ₁ to λ _n emitted from a broadband light source for WDM-PON such as an EDFA, an SLED or a multi-wavelength laser light source (not shown) may be a first optical fiber ( It is transmitted to the dual collimator 120 through 110.

The transmitted optical signals having wavelengths λ ₁ to λ _n are converted into parallel light while passing through the GRIN lens 122 of the dual collimator 120, and the light having wavelengths λ ₁ , λ ₂ , and λ ₃ by the thin film filter 130. The signal is transmitted and the optical signals of the remaining wavelengths λ ₄ to λ _n are reflected and incident on the second optical fiber 140.

The optical signals of wavelengths λ ₁ , λ ₂ , and λ ₃ transmitted by the thin film filter 130 are converted back into parallel light while passing through the collimator 200 and then to the input optical waveguide core 310 of the optical splitter 300. Is entered. The input optical signals of λ ₁ , λ ₂ and λ ₃ are branched into eight optical signals by the eight output optical waveguide cores 320 branched from the input optical waveguide core 310 and output.

Meanwhile, an optical signal having wavelengths λ ₄ to λ _n reflected by the thin film filter 130 is incident on the second optical fiber 140 and transmitted to another node.

FIG. 4 is a view illustrating a manufacturing process of an embodiment of the wavelength selector of FIG. 2.

Referring to FIG. 4, first, the first optical fiber 110 and the second optical fiber 140 are inserted into the pigtail 124 as shown in FIG. 4A and then fixed with an epoxy resin 126. Usually, the pigtail is formed of a glass material, and polished so that the inclined surface 124a is formed at the other end opposite to one end into which the optical fiber is inserted. AR coating is also used to minimize the light loss due to Fresnel reflections.

Next, as shown in FIG. 4B, the GRIN lens 122 and the thin film filter 130 are contacted, and then temporarily bonded by applying UV epoxy resin therebetween, followed by thermosetting at 90 ° C. for about 30 minutes. Here, the GRIN lens 122 has an inclined surface 122a formed at the other end of the GRIN lens 122 that is not adhered to the thin film filter 130, similarly to the inclined surface 124a of the pigtail 124. Here, it is suitable that an epoxy resin is high viscosity and low shrinkage property, and has the characteristic hardened | cured by an ultraviolet-ray.

Next, as shown in FIG. 4C, the inclined surfaces 124a and 122a of the pigtail 124 and the GRIN lens 122 are arranged to correspond to each other. Here, a laser signal is applied to one of the first optical fibers 110 and the second optical fibers 140 to check whether there are any defects in the cross section such as the AR coating of the pigtail 124 and then the inclined surface of the GRIN lens 122. Marking with a planetary pen on the top to maintain parallel with the inclined surface of the pigtail (124). In addition, in order to align the GRIN lens 122 and the dual pigtail 124 to which the thin film filter 130 is attached by applying a laser signal to one optical fiber, the GRIN lens 122 and the dual pigtail 124 are aligned in the directions of x, y, z, xθ, yθ, and zθ. Align using 6 axis high precision optical stage as possible. That is, W.D. After the pigtail 124 and the GRIN lens 122 are separated, the pigtail 124 is retracted, and the insertion loss of the specific wavelength optical signal reflected by the thin film filter 130 is measured, and the insertion loss is minimum. UV epoxide is applied between the GRIN lens 122 and the dual pigtail 124 at the point where it is temporarily bonded and then thermally cured at 90 ° C. for about 30 minutes.

Next, as shown in FIG. 4D, the pigtail 124 and the GRIN lens 122 are press-fitted into the glass tube 128, and then epoxy resin is injected to thermally cure at 90 ° C. for about 30 minutes. Here, the tip of the glass tube (128) is pressed into the pigtail 124 and the GRIN lens 122 so that the length of the tip is about 1.5cm, the glass tube 128 is a pigtail because it has a precise inner diameter with a small tolerance The center of the 124 and the GRIN lens 122 are exactly matched to maintain the spatial position.

FIG. 5 is a diagram illustrating an optical alignment process between the collimator and the splitter of FIG. 2.

Referring to FIG. 5, a laser beam is applied to any one of the plurality of optical fiber arrays 400 aligned with the optical splitter 300 (eight in this embodiment), and the optical splitter 300 and the collimator 200 are applied to the optical fiber. ) Are aligned using a six-axis high precision optical stage that can be aligned in the directions of x, y, z, x θ, y θ, z θ to precisely align each at an angle of 7.9 °. Position the single collimator 150 in front of the collimator 200 that the laser light is output, and measure the power of the light passing through the collimator 200 with the power meter equipment 50 collimator 200 at the point where the insertion loss is minimum ) And the splitter 300 are optically aligned and then temporarily bonded by injecting UV epoxy 250 between the collimator 200 and the splitter 300 and thermally curing at 90 ° C. for about 30 minutes.

6 and 7 are graphs of measurement of an optical signal passing through a wavelength division optical splitter according to an embodiment of the present invention. FIG. 6 is a transmission wavelength region measurement graph and FIG. 7 is a reflection wavelength region measurement graph.

FIG. 6 is a wavelength band of 1260 nm to 1620 nm of wavelength band mainly used for WDM optical communication, and is a wavelength band of 1310 nm and 1550 nm of transmission wavelength bands. It is a transmission wavelength band output characteristic spectrum graph of the produced wavelength division optical splitter.

7 is a reflection spectrum band output characteristic spectrum graph reflected in the remaining 1260 nm to 1620 nm wavelength band except for the transmission wavelength band 1310 nm and 1550 nm of FIG. 6.

8 is a view showing the product shape of the wavelength division optical splitter manufactured according to an embodiment of the present invention.

As described above, according to the present embodiment, by splitting the optical signal of the desired specific wavelength by arranging at the input terminal of the optical splitter a wavelength selector that transmits the optical signal of a specific wavelength and a collimator for converting and outputting the input light into parallel light. Output, and the transmission loss can be reduced.

On the other hand, the detailed description and the accompanying drawings of the present invention have been described with respect to specific embodiments, the present invention is not limited to the disclosed embodiments and those skilled in the art to which the present invention pertains the technical idea of the present invention Many substitutions, modifications and variations are possible without departing from the scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be construed as including not only the claims below but also equivalents thereof.

100: wavelength selection unit 110, 140: optical fiber
120: dual collimator 124: pigtail
122: GRIN lens 124a, 122a: inclined surface
126: epoxy resin 130: thin film filter
200: collimator 300: optical splitter
310, 320: optical waveguide core 400: optical fiber array

Claims (5)

A wavelength selecting unit for transmitting an optical signal having a predetermined wavelength among the input optical signals and reflecting the remaining optical signals to selectively output an optical signal having a specific wavelength;
A first GRIN lens for advancing the optical signal input from the wavelength selecting unit in parallel in a predetermined direction;
An optical splitter aligned at an angle of 7.9 ° with an output end of the first GRIN lens, for splitting and outputting an optical signal input from the first GRIN lens into at least two optical signals; And
And an optical fiber array optically aligned at an output end of the optical splitter, wherein the wavelength selector
A first optical fiber transmitting an optical signal emitted from the light source;
A dual collimator including a pigtail into which the output end of the first optical fiber is inserted, and a second GRIN lens connected to the pigtail at the output end of the first optical fiber to convert and output an input optical signal into parallel light;
A thin film filter which transmits an optical signal having a predetermined wavelength among the parallel light passing through the dual collimator and totally reflects the optical signal having the remaining wavelength; And
And a second optical fiber whose input terminal is inserted into the pigtail and transmits the optical signal reflected by the thin film filter to another node.
delete delete A wavelength selecting unit for transmitting an optical signal having a predetermined wavelength among the input optical signals and reflecting the remaining optical signals to selectively output an optical signal having a specific wavelength, and for advancing the optical signal input from the wavelength selecting unit in parallel in a predetermined direction. An optical splitter for branching and outputting a GRIN lens and an optical signal input from the GRIN lens into at least two optical signals; And a optical fiber array optically aligned to an output end of the optical splitter.
Applying laser light to any one of the optical fiber arrays;
Positioning a single collimator in front of the GRIN lens to which the laser light is output, and measuring power of the laser light passing through the GRIN lens using a power meter device; And
Measuring the power of the laser light and optically aligning the GRIN lens and the splitter at a point where the insertion loss is minimized, and then injecting and bonding epoxy between the GRIN lens and the splitter, wherein the wavelength comprises Method of manufacturing a split optical splitter.
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