JPS63250618A - Non-hit switching method for optical line - Google Patents

Abstract

PURPOSE:To execute switching without a hit, by connecting both ends of an existing line part of a switching object to an optical variable coupler, connecting a switching use optical line to its optical variable coupler, and switching of all of the optical power to the switching use optical line by changing successively a branching ratio. CONSTITUTION:In a first process, in a state that an existing line part has been connected from an electro-optical converter (E/O) of one station to an optical-electric converter (O/E) of the other station, both ends of a section line part 11n of a switching object of a part thereof are connected to optical variable couplers 12, 13. Subsequently, in a second process, one end of a switching use optical line 40 is connected to the optical variable coupler 13, and by changing a branching ratio of the optical variable coupler 13, 1/2 of all optical power is sent to the section line path 11n. Next, in a third process, the other end of the switching use optical line 40 is connected to the optical variable coupler 12, and by changing a branching ratio of the optical variable coupler 12, 1/2 of all optical power is sent to each of the section line part 11n and the switching use optical line 40. Also, in fourth and fifth processes, by changing successively the branching ratios of the optical variable couplers 13, 12, all optical power is sent to the switching use optical line 40, and the section line part 11n is detached. Accordingly, the existing line part can be switched without a hit of an optical signal.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Field of Industrial Application The present invention relates to a method for switching a switching section line section of a working optical line with a switching optical line without momentary interruption.

rConventional technology Generally speaking, communication cables in outlying areas are often switched to detour routes due to cable failures, cable relocation, etc. Uninterrupted disconnection is required without causing any trouble.

In the method shown in FIG. 7, which is generally adopted as such a line switching means, the working optical line (optical cable ) 1, the track section 1 of the predetermined section
n is input and output capotro 1 to 64, each of which can be cut and combined freely.
The switching line 3 can be switched to the switching line 3 by optical switches 2a and 2b equipped with the same.

To explain in more detail the line cutting method shown in FIG.
A port 6 attached to the outside of the vessel body 5 via ~44
1 to 64, and the vessel body 5 corresponding to these ports 61 to 64.
Rondo lenses 71 to 74, fixed prisms 81, 82, movable prism 83, and movable prism 83 provided therein.
It consists of magnets 91 and 92 for operating the.

In the case of the optical switches 2a and 2b, the movable prism 83, which is normally held in the state shown by the solid line in FIG. The line portion In is utilized in the coupled state, but when cutting the line portion In with the line 3 for cutting d, the movable prism 83
is moved through the other magnet 92 to the state shown by the dotted line in FIG. is cut and weighed with the switching line 3.

``Problems to be Solved by the Invention'' In the conventional example described above, by mechanically operating an optical switch, the ticket section line section of the working optical line can be switched off (because it can be switched with the optical line for A momentary interruption of the optical signal, that is, an instantaneous interruption, occurs in the optical path.

Therefore, it is necessary to synchronize the signals at the transmitting end 4a and the receiving end of the working optical line, making the line switching system complicated and expensive.

In view of the above-mentioned problems, the present invention optically performs predetermined line switching via a variable optical coupler, thereby eliminating the possibility of instantaneous interruption of the optical signal and achieving a simple and economical configuration. The present invention aims to provide a method for switching an optical line without momentary interruption.

In order to achieve the intended purpose, the present invention provides a method for switching an arbitrary section line section of a working optical line with a switching optical line without momentary interruption, which is the target of the above-mentioned switching. A variable optical coupler having at least three ports is interposed between the section line section and the section line sections on both sides of the switching section line section, and the input end and output side of these two variable optical couplers are interposed. A switching section line section and section line sections adjacent to it on both sides are connected to each other by one port each, and when switching the switching section line section with the above-mentioned switching optical line, the switching section line section is connected to the above-mentioned switching optical line. It is connected to each of the other ports in the variable coupler, and the optical power of the working optical line is branched to the switching section line section and the cutting optical line, and the branching ratio is changed by the optical variable coupler. It is characterized in that all of the power is passed through the switching optical line, and then the switching section line section is separated from the two optical variable couplers.

``Example J'' Hereinafter, an example of the instantaneous disconnection switching method for an optical line of the present invention will be described.
This will be explained with reference to the drawings.

FIGS. 1(I) to (v) show a method for switching an optical line without instantaneous interruption according to the present invention in the order of its steps.

The working optical line 11 in FIG. 1 is constructed by connecting optical cables for each section, and the working optical line 11 is
1 is installed across the electro-optical converter (Elo) of the − station and the opto-electric converter (0/E) of the other station.

At each connection point of the above-mentioned working optical line 11, a section line section 11n is provided.
-+ and the section line section 11n, section line section! As illustrated between In and the section line section 11n-1,
Optical variable couplers 12 and 13 for input and output are inserted.

Both optical variable couplers 12 and 13 in the above have the same or symmetrical structures, and these optical variable couplers 12 and 13 have the same or symmetrical structures.
．． 13 has at least three input/output ports, e.g.
2 or 2x2 input/output ports.

An example of the optical variable coupler 12.13 in FIG.
It has X2 ports.

That is, the variable optical coupler 12.13 in FIG.
and the other optical transmission body 15 has a port 20.21.
and a variable coupling end 22, and the variable coupling end 19.22 of the optical transmission body 14.15 is coupled via an adapter 16 so as to be relatively rotatable.

In this case, the variable coupling end 1 of both the optical transmission bodies 14 and 15
A ferrule may be attached to the 9.22,
One end of the adapter 16 may be fixed to either of the two variable coupling ends 19.22.

Note that both the optical transmission bodies 14 and 15 are manufactured, for example, from well-known silica-based optical fibers in the following manner.

That is, the cores 301, 302 and the cladding 31+,
312 and optical fibers 32+, 322,
and cores 351, 352 and cladding 341,
342 are used, and these optical fibers 32+, 322, 35+ are used.
, 352 are aligned parallel to each other,
The optical transmission bodies 14 and 15 are then fused together to produce a branched optical transmission body 14 and 15.

Core 30+, 302.331, 33 in the above
As shown in FIG. 3, the cross-sectional shape of No. 2 has a substantially circular shape at the fused end portion.

Thus, the optical transmission body 14.15 has ports 17.18.
20.21. They are each provided with variable coupling ends 19 and 22.

The tips of the optical transmitters 14 and 15 may be made smaller in diameter as shown in FIG. Alternatively, a method of fusion splicing the thin optical fibers 32+, 322, 35+, 352 of these clads 31+, 312, 34+, 342 is used.

Roughly speaking, the dual-optical variable coupler 12, 13 may have a configuration with three ports as shown in FIG.
Replaces B.

In FIG. 1(n) to (V), the switching optical path 40 is
It has the same configuration as the section line section (optical cable) of the above-mentioned current optical line 11.

Next, the method for switching an optical line without instantaneous interruption in the present invention will be described in the first embodiment.
This will be explained with reference to FIGS. (I) to (V).

In the currently used optical line 11 in FIG. 1(I), the section line part on,
One end is connected to the port 17 of the optical variable coupler 12, and both ends of the section line section 11n to be switched are connected to the optical variable coupler 1.
2 and port 17 of the optical variable coupler 13, and one end of the section line section 11n is connected to the port 20 of the optical variable coupler 313. In this connection mode, -station (transmission side) ) is transmitted to another station (receiving side).

FIG. 1(n) shows a state in which one end of the switching optical line 40 is connected to the port 18 of the variable optical coupler 13.

When the transmission characteristics of the switching optical line 40 and the switching section line section 11n are the same, the switching optical line 40 is the switching section line section! The length of the switching optical line 40 is set to be approximately equal to In. However, if, for example, the transmission characteristics (transmission speed) of the two are different, the length of the switching optical line 40 is set according to the difference in characteristics.

In short, these switching optical lines 40, switching section line section 1
10 may be of any type as long as the optical transmission between two predetermined points is substantially equivalent.

After connecting the switching optical line 40 to the baud 18 of the optical variable coupler 13, the switching section line section 11n is connected to the optical variable coupler 1.
Approximately 1/2 of the total optical power passing through port 17 of No. 3, and from port 18 of optical variable coupler 13 from switching optical line 40
The optical variable coupler 13
Adjust these branching ratios via .

That is, in FIGS. 2 and 3 described above, the variable coupling ends 1s and 22 of the optical transmission body 14.15 are rotated relative to each other by 45 degrees to form each semicircle at these variable coupling ends 19.22: 17301: 331, 302:332 (7) Cut each overlap in half.

Note that in the case of FIG. 1 (If), since no optical signal is transmitted to the switching optical line 4o, the receiving side of the working optical line 11 receives the optical power passing through the port 17 of the optical variable coupler 13. All x approximately 1/2. That is, the optical power PXI1131/2 transmitted from the transmitting side of the working optical line 11 is input (P refers to the total optical power transmitted from the transmitting side).

FIG. 1(m) shows a state in which the remaining end of the switching optical line 40 is connected to the port 21 of the variable optical coupler 12.

In such a state, the optical transmission body 14.
The branching ratio of the optical variable coupler 12 is adjusted by relatively rotating the variable coupling end portions 19 and 22 of 15, and the optical power P x approximately 1/2 transmitted from the transmitting side of the working optical line 11 is connected to each optical variable coupling. port 20.21 of the device 12.

Therefore, the switching section line section 111, the switching optical line 40
Approximately 1/2 of the above-mentioned optical power PX is transmitted to each of them.

Furthermore, these switching section line parts 11n, the switching optical line 4
Each optical power (approximately P/2) passing through 0 is reduced to approximately 1/2 again in the optical variable coupler 13, and becomes approximately P/4, so at this point, the optical power is input to the receiving side of the working optical line 11. The optical power is still P/4+P/4-P
/2.

FIG. 1 (IV) shows that after the above (III), the branching ratio of the optical variable coupler 12 is further adjusted, and the entire optical power P is transferred to the port 21 of the optical variable coupler 12 (=the switching optical line 40 )
It is in a state where it passes through.

This adjustment state is determined by the variable coupling end 1 of the optical transmission body 14.15.
9.22 by relative rotation of these variable coupling ends 19.
Each semicircular core 301 in 22: 331, 302
:332 by perfectly matching the overlap.

Even at the time of FIG. 1 (IV), the optical power P passing through the switching optical line 40 is reduced by approximately 1/2 by the optical variable coupler 13, so the optical power input to the receiving side of the working optical line 11 is reduced by approximately 1/2. remains approximately P/2.

FIG. 1(V) shows that after the above (IT), the optical variable coupler 13
The branching ratio of is adjusted again so that all of the optical power P passing through the switching optical line 40 passes through the port 20 of the optical variable coupler 13.

With this adjustment, all of the optical power P transmitted from the transmitting side of the working optical line 11 is transmitted to its receiving side via the switching optical line 40.

After that, from the working optical line 11, the switching section line section 11n
is removed, thus completing the desired line switching.

In the line switching described above, there is no instantaneous interruption of the optical signal, that is, no instantaneous interruption occurs in the optical transmission state from the transmitting side to the receiving side of the working optical line 11.

Moreover, the received light power (
As is clear from FIG. 6, the maximum loss (normalized by the initial power) is approximately 502 (= approximately 3 dB down), and the line switching can be sufficiently performed within the capability of the current communication system.

In particular, the length of the switching section line portion 11n and the switching optical line 4
By making the length of 0 substantially equivalent, there is no need to synchronize the two.

In addition, even if the method of the present invention is implemented using the optical variable coupler 12, 13 shown in FIGS. 4 and 5, the same effects as described above can be obtained.

Effects of the invention 1 As explained above, 1 When the method of the present invention is used, when the optical line in the working optical line and this section line section can be switched to the switching optical line without momentary interruption, an optical variable switch having at least three ports can be used. It is only necessary to switch the switching section line section to the switching optical line by using a coupler and changing the branching ratio of the switching section line section and the switching optical line via the variable optical coupler. Not only does it not cause disconnection, but its simple means and operability allow line switching to be performed efficiently and economically.

[Brief Description of the Drawings] Figures 1 (I) to (v) are explanatory diagrams schematically showing the method of the present invention in the order of its steps, and Figure 2 shows an example of an optical variable coupler used in the method of the present invention. 3 is a partially enlarged view of the variable optical coupler, FIGS. 4 and 5 are perspective views showing the other side of the variable optical coupler used in the method of the present invention, and FIG. 6 is a partial enlarged view of the variable optical coupler. FIG. 7 is an explanatory diagram schematically showing the conventional method, and FIG. 8 is an explanatory diagram of an optical switch used in the conventional method. 11・・・・・・・・・Operating optical line 11n...
...... Cut section track section on-+...
・Sectional line part 11n, l ......Sectional line part 12.13.
...... Optical variable coupler 14.15...
・Optical transmission body 18...adapter 17.18...
......Port 18......Variable coupling end 20.21
......Port 22......Variable coupling end 30+, 3
02...Core 311.312...Clad 321.322
...... Optical fiber 331.332... Core 341.342... Clad 351.352... Optical fiber 36...
・・・・・・Glass fiber 40・・・・・・・・・
...Switching optical line agent Patent attorney Saito A Yu 2nd Prisoner 4 Figure 5

Claims (3)

[Claims] (1) In a method of switching an arbitrary section line section in a working optical line with a switching optical line without momentary interruption, there is a gap between the section line section to be switched and the section line sections on both sides of the switching section line section. , a variable optical coupler having at least three ports is interposed, and one port each on the input side and output side of these two variable optical couplers connects the switching section line section and the section line sections on both sides thereof. When switching the switching section line section to the above-mentioned switching optical line, connect the switching optical line to each of the other ports of the above-mentioned double optical variable coupler, and switch the optical line of the current optical line. The power is branched into the switching section line section and the switching optical line, and the entire optical power is passed through the switching optical line while the branching ratio is changed by an optical variable coupler, and then the switching section line section is connected to the above two sections. A method for switching an optical line without instantaneous interruption, characterized by disconnecting it from a variable optical coupler. (2) The optical variable coupler is constructed from an optical fiber.
2. The method for switching an optical line without interruption according to claim 1, comprising a pair of branching type optical transmission bodies, the variable coupling end portions of these optical transmission bodies being butted against each other so as to be relatively rotatable. (3) The method for switching an optical line without instantaneous interruption according to claim 1 or 2, wherein the core shape of the variable coupling end portion of the variable optical coupler is approximately semicircular.