KR20090101104A - Method of producing module for optical fiber alignment and optical transmission apparatus for the same - Google Patents

Abstract

PURPOSE: A module manufacturing method for arranging optical fiber and an optical transmission device for the same are provided to transmit image signal of multiple channels by one input by using multiple mode optical divider. CONSTITUTION: An optical transmission equipment includes an optical source unit(102), an image mode optical divider, an output port and a receiver(20). The optical source unit outputs and converts the inputted electric picture signal to the optical according to the image mode. An image for each mode optical splitter outputs and separates the optical signal outputted according to the image mode. The output port transmits the optical signal of each image mode through an optical fiber(30). The receiver is corresponded to lots of the output ports.

Description

METHOD OF PRODUCING MODULE FOR OPTICAL FIBER ALIGNMENT AND OPTICAL TRANSMISSION APPARATUS FOR THE SAME}

The present invention relates to an optical transmission device, and more particularly, to an optical transmission device capable of simultaneously transmitting an image to several video media by separating one input into N outputs and a method for manufacturing a module for aligning optical fibers thereof. .

The image transmission device transmits a digital image signal consisting of red (R), green (G), blue (B), and clock (C) signals by a DVI (Digital Visual Interface) method and a HDMI (High Definition Multimedia Interface) method. .

HDMI (High Definition Multimedia Interface) is a format that integrates video and audio signals into one digital interface, and is used in A / V devices such as DVD players, HDTVs, and set-top boxes. HDMI supports standard, extended or HD video as well as standard to multichannel audio signals, and a single terminal can transmit uncompressed digital video signals of up to 5 gigabytes per second from a source device to a video medium (display device). .

However, since the digital video signal has a high frequency of several hundred MHz to several GHz, in the case of the electrical transmission method, a normal signal transmission distance (usually 5 m) is limited by signal attenuation. Therefore, an image transmission device (optical HDMI) capable of converting and transmitting a digital image signal into an optical signal during long distance transmission has been developed. The optical HDMI consists of a light source of an input terminal which largely generates a signal, and a light source of an output terminal which detects the intensity of the light source. However, since optical HDMI has a structure in which a transmitter and a receiver are connected one-to-one through a single optical cable, in order to transmit one image to a plurality of video media (display devices), optical HDMI corresponding to the number of video media to be applied is required. There is a disadvantage.

An object of the present invention is to divide the input video signal of one HDMI into multiple channels to transmit the image to a plurality of video media at the same time to reproduce the image, separate arrangement of the optical fiber used to reduce the transmission loss between the transceiver The present invention provides a module manufacturing method for optical fiber alignment and an optical transmission device for the same, which can be easily mounted without a device and can be aligned with low transmission loss.

According to one aspect of the present invention, there is provided a module manufacturing method for optical fiber alignment and an optical transmission device therefor. According to this apparatus, a light source unit converts an input electrical image signal into an optical signal by a plurality of light sources emitting light of different wavelengths and outputs the image signal for each image mode; An optical splitter for each image mode for separating and outputting the same optical signals outputted for each image mode; A plurality of output ports each transmitting an optical signal in each image mode through an optical fiber; And a plurality of receivers corresponding to a plurality of output ports one-to-one, restoring an optical signal of each image mode received through an optical fiber to an electrical image signal and providing the image signal to a corresponding image medium. According to this method, a groove corresponding to the diameter of the optical fiber to be mounted is formed in order to mount the optical fiber on the silicon substrate, and the formed groove is isotropically etched with KOH aqueous solution to be processed into a rhombus groove.

According to the present invention, there is an advantage that a multi-mode optical splitter can transmit video signals of multiple channels at high speed with one input. In addition, it is possible to easily mount the optical fiber in the rhombus-shaped groove without a separate aligning device or mechanism, can be aligned with low transmission loss, and mass production is possible.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the following description, when there is a risk of unnecessarily obscuring the gist of the present invention, a detailed description of well-known functions and configurations will be omitted.

1 is a view schematically showing the configuration of an optical transmission device according to an embodiment of the present invention.

The transmitting unit 10 includes a transmitting connector 101, a light source unit 102, an optical splitter 103, a ferrule 104, and the like, and emits light having different wavelengths from the input electrical digital image signal. The light source is converted into optical signals by two light sources and simultaneously output to a plurality of output ports, that is, ferrules 104. In one embodiment, the transmitter 10 is a multi-channel HDMI splitter capable of transmitting image data at a transmission rate of 3.4 Gbps, and multiple video media (receivers) using a multimode optical splitter 103 at one HDMI input. Video signal can be transmitted simultaneously. In the following description, the video signal means that the audio signal is included. The audio signal may be included in the green and blue signals, depending on the application method. It describes the four-channel method of R: Red), G (Green), Blue (B: Blue), and Clock (C: Clock) signals.

The light source unit 102 includes a red light signal, a green light signal, a blue light signal, and a clock corresponding to the red (R), green (G), blue (B), and clock (C) electrical signals output from the transmission connector 101. Output optical signals respectively. The light source unit 102 includes four light sources R that emit light having a wavelength (for example, any one of 850 to 1550 nm) corresponding to the red (R), green (G), blue (B), and clock (C) electrical signals. A light source, a G light source, a B light source, a C light source), and a light source driving unit for driving the light source corresponding to the red (R), green (G), blue (B), and clock (C) electric signals. As a light source of the light source unit 102, a laser diode (LD) may be applied, and in one embodiment, a vertical cavity of surface emission laser (VCSEL) may be applied. In one embodiment, the light source unit 102 is composed of a four-channel VCSEL driver and a transmission HDMI IC.

The optical splitter 103 receives each optical signal output from the light source unit 102, separates the optical signal and outputs the optical signal through each output port, that is, the ferrule 104. In an exemplary embodiment, the optical splitter 103 may have four optical splitters applied to each image mode (the same number of optical splitters as the image signals R, G, B, and C), and the red optical splitter 103-1. And a green optical signal splitter 103-2, a blue optical signal splitter 103-3, and a clock optical signal splitter 103-4. The red optical signal splitter 103-1 outputs an optical signal corresponding to red (R) to the plurality of ferrules 104, respectively, and the green optical signal splitter 103-2 outputs an optical signal corresponding to green (G). Are output to the plurality of ferrules 104, and the blue optical signal splitter 103-3 outputs the optical signals corresponding to blue (B) to the plurality of ferrules 104, respectively, and the clock optical signal splitter 103-. 4) outputs an optical signal corresponding to the clock C to the plurality of ferrules 104, respectively. Here, the number of ferrules 104 is set equal to the number of receivers 20. In one embodiment, each of the light splitters 103-1 to 103-4 may be a 1 × 8 splitter. In this case, each of the four optical splitters 103-1 to 103-4 is connected to eight ferrules 104, and outputs a red light signal, a green light signal, a blue light signal, and a clock light signal for each ferrule 104. do. That is, four optical signals of red, green, blue, and clock are output for each ferrule 104. Here, each of the eight ferrules 104 corresponds one-to-one to the eight receiving units 20, and the four optical splitters 103 are used to output image mode optical signals (R optical signals, G optical signals, B optical signals, and C optical signals). The output ports, that is, the same number as the number of ferrules 104 are separated and output to each output port.

In another embodiment, the multimode optical splitter 103 may be applied with eight, twelve, sixteen, twenty, ..., thirty-two (4N) optical splitters. When configuring 8 (/ 12/16 ..., 4N) optical dividers (4N number of optical dividers for video signals R, G, B, and C), red optical signal divider, green optical signal The splitter, the blue optical signal splitter, and the clock optical signal splitter are each composed of two (3/3/4/4 /.../ N) each, and each of the optical signals R, G, and B output from the light source unit 102 is provided. A demultiplexer is provided between the light source unit 102 and the optical splitter 103 for dividing the optical signal of (C) into two quarters (third quarter quarter quarter ... / N quarter branches). Here, 4N (N is a natural number of 2 or more), the optical splitter 103 is separated by equally divided by the total number of output ports divided by N rather than equally divided by the total number of output ports, that is, the ferrule 104 Output to the output port.

In the above, when the number of ferrules 104 is 16, four optical splitters having a 1 × 16 splitter may be used, but eight optical splitters having a 1 × 8 splitter may be used. In this way, the number of branches of the optical splitter 103 or the number of the optical splitters 103 may be increased to connect more image media (via the receiver 20).

Ferrule 104 is an optical component used for alignment of core wires in a connection using an optical connector. Ferrule 104 is a cylindrical hole through which one minute hole (Hall) that can accommodate the optical fiber 30 is penetrated. Looking in more detail as follows.

An optical connector is also called an optical fiber cable connector because it is an essential component for building an optical communication network. The optical connector basically consists of a plug and an adapter. The plug is a part that directly connects the optical fiber, and is composed of a ferrule in which the optical fiber is fixed and polished in cross section with the optical fiber, a sleeve for aligning the ferrule, and a part for coupling the adapter with the adapter.

Optical connectors are classified into single-core connectors and multi-core connectors according to the connection type. In addition, it is divided into single-core and multi-core types according to the number of cores of the optical fiber constituting the module, and divided into single mode and multi-mode according to the type and type of optical fiber used. Single core type includes BICONIC type, Single Coupling type, ST type and FC type. The multi-core type includes a mechanically transferable (MT) type, an MT push on (MPO) type, a miniature unit-coupling (MU) type, and a multi-fiber array connector (MAC) type.

In one embodiment, an MT type ferrule 104 is used. The MT type consists of two MT connector plugs, two guide pins and a clamp spring. The plugs are aligned, aligned and clamped with guide pins. The refractive index matching body is apply | coated to the connection cross section. The MT type can collectively connect ribbon fibers to, for example, 12 cores (in the present invention, four-channel ribbon fibers are used). Ferrules include ceramics, stainless steel, glass, plastics, and elastomers.

In one embodiment, the MT type ferrule 104 is used, but other optical connectors such as FC, SC, and LC type connectors can be used.

The receiver 20 includes a ferrule 201, a light receiver 202, a receiver connector 203, and the like. The receiver 20 receives an optical signal transmitted through an optical cable (optical fiber 30) and restores the optical signal to an electrical digital video signal. As an example of the output may be output to the applied display device (LCD). Since the ferrule 201 of the receiver 20 is connected one-to-one with the ferrule 104 of the transmitter 10, the number of receivers 20 is equal to the number of output ports of the transmitter 10, that is, the number of ferrules 104. . One image medium for each receiver 20 is connected through the receiver connector 203.

The light receiving unit 202 converts and outputs an optical signal (a red optical signal, a green optical signal, a blue optical signal, a clock optical signal) input through the optical fiber 30 to an electrical signal. PIN PD (Photo Diode) is mainly used as the light receiving element of the light receiving unit 202. In one embodiment, the light receiver 202 uses an amplifier for driving a four-channel PD and a receiving HDMI IC.

The receiving connector 203 is formed to be physically connected to an image display apparatus (LCD) applied as an example of an image medium, and outputs the image signals R, G, B, and C output from the light receiving unit 202 to the image display apparatus ( LCD). That is, four electrical video signals of red, green, blue, and clock are output to the image display device (LCD) for each of the receiving connectors 203.

As described above, the optical transmission device of the present invention includes a multi-mode optical splitter 103 between the light source unit 102 of the input terminal and the light receiving unit 202 of the output terminal, separated into N outputs for one input, and then the optical fiber 30 Send through). In this case, the light source of the light source unit 102 may be a butt-coupling type of FP LD and DFB LD of 1310 nm band as well as a low-cost VCSEL, but mainly uses a VCSEL for high-speed data transmission. In addition, VCSELs with flip-chip bonding structures are easy to fabricate.

The optical transmission module which can be easily mounted on the optical fiber 30 and can be aligned at low loss without additional alignment device or mechanism and improves the transmission speed is manufactured as follows.

As shown in FIG. 2, in order to mount the optical fiber 30, the silicon substrate 201 processes a groove having a rhombus shape using directional etching characteristics. The minimum depth d of the groove for mounting the optical fiber 30 is determined by the following [Equation 1].

Where d is the depth of the groove in which the optical fiber 30 is to be mounted, w is the width of the groove (Open) above the groove. In addition, α means the angle of the groove. In one embodiment, the angle α of the groove is 54.74 degrees and the open width w is 64.5 μm.

The height and slope of the sidewalls of the rhombus grooves are controlled by mechanical or etching processes. For example, the fabrication principle is that a mask layerron SiN-deposited substrate was first grooved about 125μm, the diameter of an optical fiber, using a dicing saw or silicon deep etching equipment (2a), followed by 2 hours at 60 ° C in a 20% KOH aqueous solution. After etching, a rhombic groove is processed (2b). Since this principle is a oriented crystal structure in a silicon wafer, isotropic etching is performed in a specific direction even in grooves processed in the vertical plane, so that an etching surface of a diamond structure (diamond shape) can be processed. Mounting the optical fiber 30 as shown in Figure 3 '2b' and the processed rhombus groove in Figure 2, there is no need for an additional alignment device or mechanism.

In addition, when the silicon directional etching is used as shown in FIG. 4, in the case of the optical connection between the light source VCSEL and the optical fiber 30, gold (Au) may be coated on a 45 degree inclined surface to be used as a reflective surface. In addition, when the silicon-based orientation using the substrate 201 in the SiOB (Silicon Optical Bench) structure, that is, when the light source (VCSEL) is also mounted as shown in FIG. 4 after mounting the optical fiber 30 in a rhombic groove It is also possible to use gold as a reflective surface by coating a 52.4-degree isotropically etched surface. As such, when the reflective surface is formed through the coating, the amount of light incident on the core of the optical fiber 30 can be adjusted.

In one embodiment, a multi-mode optical fiber having a core diameter of 50 μm and a refractive index distribution having a curved index structure is used as the type of the four-channel ribbon optical fiber 30. And the transmission length of the four-channel ribbon optical fiber 30 is limited to within 300m.

In addition to mounting the light source VCSEL after mounting the optical fiber 30 in the rhombic groove described above, the optical connection between the optical fiber 30 and the light source PIN PD is also formed in SiOB as in the case of the VCSEL. Butt-coupling is also possible to align the optical fiber 30 to the inclined surface or directly to the laser emitted surface. Butt-coupling is one of the simplest and most efficient optical coupling methods for joining the ends of the optical fiber 30 as closely as possible to the optical device.

While the invention has been described in connection with some embodiments herein, it should be understood that various modifications and changes can be made without departing from the spirit and scope of the invention as would be understood by those skilled in the art. something to do. Also, such modifications and variations are intended to fall within the scope of the claims appended hereto.

1 is a diagram schematically showing a configuration of an optical transmission device according to an embodiment of the present invention.

Figure 2 is a view showing a rhombic groove processing for mounting the optical fiber according to an embodiment of the present invention.

Figure 3 is an exemplary view showing a rhombus-shaped optical array in which the optical fiber is mounted according to an embodiment of the present invention.

4 is a diagram illustrating a configuration in which a light source is mounted together in the light array of FIG. 3.

* Explanation of symbols for the main parts of the drawings

10: transmitter 20: receiver

30: optical fiber 101: transmission connector

102: light source unit 103: distributor

104,201: Ferrule 202: Light-receiving part

203: Receive connector

Claims (13)

As an optical transmission device, A light source unit converting the input electrical image signal into an optical signal by a plurality of light sources emitting light having different wavelengths and outputting the image signal for each image mode; An optical splitter for each image mode for splitting and outputting the same optical signals outputted for each image mode; A plurality of output ports each transmitting an optical signal in each image mode through an optical fiber; And And a plurality of receivers corresponding to the plurality of output ports one-to-one, and configured to restore an optical signal of each image mode received through the optical fiber to an electrical image signal and provide the image signal to a corresponding image medium. The method of claim 1, The optical fiber is a multimode optical fiber, arranged in a rhombus groove. The method of claim 2, Each of the video modes is a red (R), green (G), blue (B), clock (C) signal mode. The method of claim 3, The optical fiber is a four-channel ribbon optical fiber. The method of claim 4, wherein The optical splitters for each video mode are four optical splitters each responsible for a red (R), green (G), blue (B), and clock (C) optical signal. Four optical splitters divide and output the optical signals output for each of the image modes equally by the number of the output ports, respectively. The method of claim 4, wherein The optical splitters for each video mode are 4N optical splitters (N is a natural number of two or more) that are responsible for each of the red (R), green (G), blue (B), and clock (C) optical signals. 4N optical splitters respectively output an optical signal output for each image mode by dividing the total number of the output ports equally by the number divided by N. The method according to any one of claims 1 to 6, Each of the plurality of receivers corresponds one-to-one with the image medium. Module manufacturing method for optical fiber alignment, a) forming a groove corresponding to the diameter of the optical fiber to be mounted to mount the optical fiber on the silicon substrate; And b) isotropic etching the grooves with an aqueous KOH solution to process the rhombus-shaped grooves. The method of claim 8, Wherein said etching is etched for 2 hours at 60 degrees of 20% KOH aqueous solution. The method according to claim 8 or 9, In step a), the minimum depth (d) of the groove is determined by the following equation, the module manufacturing method for optical fiber alignment.

(d is the depth of the groove where the optical fiber is to be mounted, w is the width of the groove above the groove, α is the angle of the groove) The method of claim 10, Wherein the angle α of the groove is 54.74 degrees and the opening width w is 64.5 μm. The method of claim 11, 54.74 degrees of the angle (α) of the groove coated with gold (Au) is used as a reflecting surface, module manufacturing method for optical fiber alignment. The method of claim 12, And aligning the VCSEL or PD with the optical fiber.

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