JPS58151139A - Optical network device - Google Patents

Abstract

PURPOSE:To use a receiver having a small dynamic range and to constitute an optical network inexpensively, by performing star connection with an optical branching coupler consisting of an optical branching coupling circuit formed in a polymer film and a plastic optical connector. CONSTITUTION:A personal computer and an optical branching coupler are connected in star via an adaptor. The adaptor converts between optical and electric signal. In an optical branching coupling circuit 8, an optical conductive path having a shape formed with plural branching paths 8b at both ends of a common path 8a is formed on a polymer film. This film is bonded by being clipped between two plasic sheets. On a base 7, an optical fiber array piece 11 putting optical fiber cores together and arranged on one base is positioned and butted at the end of the circuit 8 for bonding with a transparent bonding agent, and the optical fiber 9 and the branching conductive path 8b are coupled with low loss. A plastic connector plug 12 is fitted to the other end of the optical fiber core 9.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is a book about an optical network device that interconnects a plurality of personal computers with optical fibers.

<Background technology> Until now, systems and devices that electrically configure networks between large computers and multiple terminals have been put into practical use.
Rounding K, which transmits wideband electric signals over long distances, is
The price of transmission cables and transmission equipment will increase. It took some time to construct a network between personal computers, whose prices have been rapidly decreasing in recent years, using the expensive transmission cables and transmission devices. Optical fiber has a wide band and is resistant to casting noise, making it suitable as a communication medium for computing institutions.
Figure 1A shows an optical network system connecting computers.
Various systems shown in B and C! Ik has been proposed. Of these, % jlx[mu, B is one in which the terminals TlTl. Figure 1 A is connected in a rim shape, Figure 1 B
are connected in a loop. These figures 1, B
In network equipment shown in K, the branching loss increases exponentially in proportion to the number of Fi terminals, and as the number of terminals increases, optical receivers with a large dynamic range are required, making it impossible to increase the number of terminals. There are some drawbacks. Figure 1C
10U each terminal T1 'l' g * @... shown in 1
The strings are connected in a star shape, with the strings connected by the strings 1 and 3 and the strings connected by the strings 7 and 2. In this case, the branching loss increases only logarithmically with respect to the number of terminals, and a network of the necessary size can be constructed using optical receivers with a relatively small dynamic range. However, in configuring such a network device, an optical splitter/coupler 3 that branches input light into multiple optical fibers is required, but a conventional optical splitter/coupler 8 of this type has a large loss. However, the disadvantage was that the transmission distance could not be increased. In addition, such optical network equipment uses a very large number of optical connectors, and the cost of these optical connectors is very high.The cost of optical connectors in optical network equipment is enormous. .

<41 inventions! Summary An object of the present invention is to provide an optical network device that allows the use of a dynamic range small-b receiver and can be constructed at low cost.

According to this invention, a star-like connection can be performed using an optical branching/coupling device consisting of an optical branching/coupling circuit formed in a polymer film, a plastic connector, and K.

<Embodiment> FIG. 2 shows an example of an optical network device according to the present invention, in which a plurality of personal computers PCIPCB and .
(representatively written as PC) are respectively connected to adapter w = ut ADIAD11'' (representatively written as AD),
These adapters ADsADLl- are connected to an optical branching coupler 4 via an optical fiber 2. Data input/output between the personal computer PC and the adapter unit D is based on the transmission I
It is carried out according to the application standard 18232C in voice 7 ace. Electrical signals sent from the personal computer PC are converted into optical signals by the adapters jLj and D, and are coupled to the optical fiber 2.

The optical signal input to the optical branching coupler 4 is distributed,
It is sent to each of the other adapters.

The AD adapter sends the optical signal to the electrical signal KK personal computer PC. Next, each part constituting the optical network device of Jin's invention will be explained in more detail.

<Optical branching/coupling device 4> FIG. 3 shows the structure of the optical branching/coupling device 4. A base 7 is attached to the center of the bottom plate 6 of the case 5, and an optical branching/coupling circuit 8 is mounted on the base 7. installed. Optical branching and coupling circuit 8
As shown in FIG. 4, an optical waveguide having a shape in which a plurality of branch paths 8b are formed at both ends of a common path 8a is constructed of a polymer film, and this polymer film is formed between two plastic sheets. The end face of the branch path 8b is polished. The optical branching/coupling circuit 8 can be manufactured by the method described in Japanese Patent Application Laid-Open No. 50-22648. That is, a transparent plastic film, such as a polycarbonate film, impregnated with a polymerizable monomer, such as methyl acrylate, is formed by a casting method, the monomer is selectively polymerized with light, and the unreacted monomer is then polymerized. is removed to form a nine-waveguide type branch circuit as shown in FIG. On top of the film, a circle-shaped Y fabric (the part surrounded by black is opaque) as shown in Figure 4 was layered, and ultraviolet rays were irradiated with an ultra-high pressure mercury lamp, and the bales were heated at 90C. By vacuum drying to form a refractive index difference between the 1 ml ultraviolet irradiated area and the non-irradiated area, the light Jt & path shape original branching and coupling circuit 8 is formed.
is obtained. This film is sandwiched and bonded between two plastic plates as described above, and the end surfaces are polished.

The branching waveguides 8b at both ends of the optical branching and coupling circuit 80 are arranged at intervals equal to the outer diameter of the optical fiber, and the thickness of the branching waveguide 8b and the thickness of the film are selected to match the core diameter of the optical fiber. has been done. Optical fiber array pieces li are arranged on a single substrate with optical fiber cables closely attached between the ends of the optical branching and coupling circuit 8 on the base 7.
By aligning and abutting each other and bonding with a transparent adhesive, each original fiber 9 and each of the four branched wave paths 8b are coupled with low loss. A plastic optical connector plug 12 is attached to the other end of the light traveling twin piper (15119) connected to the optical branching/coupling circuit 8.

<Optical Connector Plug> The structure of the glass optical connector plug 12 is shown in FIG. An optical fiber cord (not shown) is inserted into the center hole 14 on the right side of the figure, and its Kepplar (reinforcing material) is sandwiched between the cylindrical body 15 and the presser tube 16 and fixed by adhesive. The presser tube 16 is covered with an elastic body 17 for bending and retaining the optical fiber cord. A guide 18 is screwed to the side of the cylindrical main body 150 opposite to the elastic body 17, and a cylindrical core 19 is disposed within the guide 18 so as to be movable in the axial direction.

The strand of the optical fiber cord inserted into the main body 15 is inserted into the core 19, and the optical fiber spring of the strand is inserted and fixed into the hole 21 formed in the end surface of the core 19. The core 21 is biased outward by a coil spring 22 and the guide 18
is provided with a stop for removing the core 21. An identification sleeve 23 is arranged outside the guide 18. The core 19 is inserted into the connector adapter guided by the guide 18, and is tightened to the shear adapter by the screw of the sleeve 23. Main body 15, presser tube 16, guide 18, core 19, sleeve 2
3 is made of plastic.

The core 19 can be manufactured as shown in Japanese Patent Application No. 56-93731. That is, a circular hole having the same diameter as the optical fiber wire is formed in the center of one end surface of a rond made of a metal, two-layer structure, or a metal and one cell structure,
A small rod is inserted into the circular hole, and the small rod is inserted, and nickel electroforming is applied to it using the nine-rad as a master plate.It grows to a predetermined thickness and forms a nine-electroformed layer. Only the four rods are extracted from the illumination layer and made of electroformed metal, and the electroformed metal part, the pipe, and a pair of metal parts and K are used to form a mold for molding the core. The plastic is injected into the mold which is formed in the mold for molding the core, and then the core is formed.

In FIG. 3, the optical fiber array pieces 11 are glued to both ends, and the nine-optical splitter coupling circuit 8 is fixed as one piece to the bottom plate of the metal case 6, and the optical connector plugs 12 are attached to the front plate of the metal case 6 in two rows and six rows. It is installed and inserted into the receptacle pull 25 for the optical travel connector plug. In this case, the optical fiber core wire 9 is connected so that the upper stage and the lower stage can be connected to the input optical 7 eyer and the output optical fiber, respectively. This optical branching coupler 5 has six ports.

<Adapter unit> Next, there is a rounded adapter (two AD) that combines the optical signal in the optical transmission line and the electrical signal of the personal combinator.
I will explain about it. FIG. 6 shows the external appearance of the adapter unit AD, in which there are three logic processing unit packages 2 in the case 26.
7. One optical transceiver package 28, power supply section and R8
It is composed of a 232C interface chair connector section 29. The power supply unit is composed of a switch 31 and two display lamps 32, and a power supply 33 supplies four power supplies of ±5V and ±12V.

As the active connector 34 used to connect the light emitting element or light receiving element of the optical transmitter/receiver package 28 and the input/output optical fiber cord 2, the same receptacle as that used for the optical branching/coupling 464 is used. The optical core adapter 2 is attached to the attachment part of the casing 26, and the microphone 4 lenses and elements are aligned and attached to a metal holder at the rear of the casing 26. A GaAjAa light emitting diode (luminescence center wavelength 0.88 Js) is used as the light emitting element, and a KU81-PIN7 photodiode is used as the light receiving element.

Next, the function of the adapter unit D will be explained with reference to FIG. Adapter unit AD12) Logic processing unit package 28Fi, RB2B2C interface processing unit which is an interface with personal computer PC, and &192M-riμtsk oscillation unit 37.75KH1
An MI8C Hara cage 39 having a micro-block generator 38, an SM and DP backlog 41 for converting data from a personal computer PC into optical transmission line data format, and an electronic transmission line data format. It consists of a combination of RADP packages 42 that convert data formats in the signal section. R82 at 4800 baud between the personal computer PC and the adapter Hyo Nittom D
32C interface is used.

This unit data format on the cable is gsE
Shown below. The personal computer PC, which operates in the transmission mode, displays nine pieces of information on one screen, and assembles the unit data format shown in Fig. 8 into a predetermined data format as shown in Fig. 9 in succession (adapter unit)A.
Send DK.

The data length is a fixed length of 256 bytes, and the a priori is F
8, a receiving station address DA, a transmission waste address OA are added, and F9 and OD are added to the end.

In the transmission function section of the adapter unit D, the transmission data 41
The head and end detection circuit 43 detects the head data, and the control circuit 45 inputs the data into the buffer memory 44 until the tail data is detected. When the last data has been stored, a message is sent to the personal computer PC.
Send the BυBY signal through the transmission preparation@D S R1 and buffer it under the control of the control circuit 4s 4
4 is read out, and the packet generation circuit 46 packetizes the data into a format with synchronization signals added before and after the 256 bytes as shown in FIG. The signal is CMI-encoded by the EO Enit 48, converted into an optical signal, and sent to the Optical 7-IPA. When the data exit is finished, send ready signal to send ready signal D8
11 to the personal combinator PC and returns to the initial state mK.

After initialization, the receiving function section of the adapter 2nitm D is in a state of waiting for data from the optical receiving circuit. The incoming optical signal is converted into an electrical signal by the 0E3LxL cut 49, the CMI code is demodulated by the demodulation circuit 51, and the macro clock detection (
b) A clock is detected on the path 52, and the packet guarantee circuit 5
8 is input. When the synchronization signal 8YNC is input, it is detected by the head/end detection circuit 54, and preparations are made for storing the message. When a frame pattern indicating the start of a message is input, the message data is transferred to the control circuit of the control circuit 55 via the serial-to-parallel conversion circuit 56 to the buffer memory 57 until the end 7 frame pattern is input.
To! pay. When the end frame pattern is detected, the input gate from the optical receiving circuit is closed and the message data is stored. At the same time as this operation is performed, the control circuit 55 activates the buffer s7, and begins to output the data to the personal combinator PC via the ink processing section 36 using the received data. personal combinator pc
Optical data that arrives while sending data to is ignored. When data transmission is finished, the input gate opens and the device returns to the receiving state. Personal Punbieta in Receiving Mode PC always monitors whether or not data is being sent, and if there is data input, it reads it, determines whether the message is addressed to you, and sends it to you. If it is data, the data portion of the message is extracted and displayed on the entire writing surface of the video RAMK.

In addition, I mentioned it first *#! In the optical signal data format shown in FIG. 10, the optical signal is CMI encoded.

As shown in Figure 11, the CMI code changes between a high level and a low level in the middle of one time slot for the "0" code, as shown in Figure 11, and the 11# code changes between high and low levels as shown in Figures B and C. Depending on whether the previous level was low or high, that level is maintained for 1 time. The 8YNC optical signal has a @O"@1"0"1" pattern and is used as a setup signal for the optical receiving circuit.

A frame pattern is inserted in the 32nd byte of the 8YNC signal and the 1st byte of the 5YNC signal in the second half to separate the message area.

<Performance of each part> Next, the performance of the optical branching coupler, optical connector, and optical transmitter/receiver section will be explained. Table 1 shows nine loss measurement results of the optical branching coupler 4. Average loss (including branch loss 7.8 dB) is 11.0 dB, distribution unevenness (maximum loss - minimum loss)
was 2.4 dB. The connection loss of an optical connector is determined by Obuchi and is 1 fII, with an average of 0 and 4 dB. Therefore, the excess loss of the optical branching and coupling circuit excluding the connection loss of the optical connector is estimated to be about 2.4 dB. Mae, light minutes wt.
#When the metal 40 yen connector plug is repeatedly connected and disconnected, the loss fluctuation is less than 0.05 dB.

Figure 12 The average connection loss is 0.48 due to the hisdogzum of the connection loss in steady mode excitation of the optical connector plug assembled using the core manufactured from the mold made by the electroforming method (Fig. 12).
It shows a small value of dB.

Fiber input power Fi-11,4± in the optical transmitter
0.6 dBm, and the incident power fluctuation due to attachment and detachment of the optical connector plug is 0.05 dBnx or less.

The minimum light reception level in the optical receiver is -33 to -3 for a rate of 10-'K, as shown in the measurement results of section 13.
It was 6 dllm (average light par 9-).

FIG. 14 shows the light level diagram (pulse peak value) obtained from the above measurements. With a margin of 3 dB, a cable loss of 8 dBiil& is allowed, allowing transmission of approximately 2.

Next, a specific method of operating software for system operation using an embodiment of the optical network device according to the present invention will be described. First, for each terminal, a rounded name originating address (transmitting station address) 0m that distinguishes between a plurality of terminals is designated by a number. Next, set either the sending program or the receiving program. After the above operations, the receiving personal computer PC is ready)
Waiting for a message to be sent.

Input the destination address (receiving station address) D of the personal combiator operating in the receiving mode on the transmitting personal computer. With the above operations, sending and receiving is possible. At this time, on the sending personal computer PC, by inputting the number of the one-page information in the subprogram and the 0m of the personal combinator PC, the desired personal computer (one or more) can be sent.

As explained above, the loss of the optical branching and coupling circuits and plastic optical connectors that make up the optical branching and coupling device is small, so even if the distance between the terminals is large, a network that can transmit signals from each terminal's computer to multiple computers is possible. Because of the features of the manufacturing method of the polymer optical branching and coupling circuit plastic optical connector, it has the advantage of being a very low-cost optical network device.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of various conventional optical network devices, Fig. 2 is a block diagram showing an example of the configuration of the original network device according to the present invention, and Fig. 3 is a block diagram showing an example of the configuration of the original network device according to the present invention. Figure 4 shows a plan view with the upper surface partially cut away, Figure B is a front view, Figure C is a partially cutaway side view, and Figure 4 is a structural diagram of the optical branching and coupling circuit. Fig. 5 is a sectional view showing an example of a plastic optical connector plug, Fig. 6 is an external view showing an example of Adapter Enitm D, Fig. 7 is a block diagram showing the ADo function, Fig. 8 Figure #1 R8282c Inter 7Ace Data Format, Figure 9 is Electrical Signal Data 7 Auto,
Figure 11g10 shows the optical signal data format, Figure 11 shows the CMI code, Figure 12 shows the plastic optical; 14 are level diagrams of the optical transmission system of this device. 2: Optical fiber, 4: Optical branching coupler, PclPcm...
...: Personal computer, ADIADI...
:Adapter unit. Patent applicant Nippon Telegraph and Telephone Public Corporation agent Single needle Table 74 Fork 5 Figure 214 Figure 6 Figure A'12 Connection loss (dB) Figure 713 Average optical power dBm

Claims (1)

[Claims] (1) A plurality of personal computers, an adapter unit connected to each personal computer, converting an electrical signal into an optical signal, and converting an optical signal into an electrical signal, and - a phototactic branching and coupling circuit formed in a molecular film. An optical branching coupler made using the above-mentioned optical branching coupler, and two transmitting and receiving units in which the optical branching coupler and each of the above-mentioned adapter units are connected via the optical branching coupler and a plastic connector.
Optical network equipment consisting of optical fibers.