JP3282644B2 - Optical component inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical component inspection apparatus for measuring the optical characteristics of passive optical components such as optical connectors and optical couplers.

[0002]

2. Description of the Related Art Optical characteristics inspection items for passive optical components include:
Insertion loss; wavelength dependence, polarization dependence, and temperature dependence of insertion loss; and return loss. Conventionally, when inspecting the optical characteristics of such optical components, each optical component is inspected one by one using a dedicated measuring device for each inspection item. Therefore, when inspecting a large number of optical components and an optical component having a large number of optical input ports or optical output ports,
Since the labor and time required for the inspection are enormous, automation and speeding up of the inspection are desired.

[0003] In recent years, an apparatus for automatically inspecting optical components has been developed.

[0004] For example, Bell Communicat
ion Research, Inc. Technic
al Advisory TA-NWT-00032
6, Generic Requirements fo
r Optical Fiber Connector
s, Issue 4, December 1993. Discloses an optical characteristic measuring device for an optical connector.

[0005] FIG. 4 shows a transmission measurement equipment (Transmission Measurement Facility) in section 5.2.1 of the above-mentioned document.
nt Facility). As shown in FIG. 4, the present apparatus includes a first switch 1 and a second switch 1 that can switch n optical components to be measured.
And fixed ports 1 to n of the first and second switches 101 and 102, respectively.
Between mode filters 103A and 103A, respectively.
B, optical connectors 104A and 1 as optical components
04B is connected. The movable port of the first switch 101 is connected to the first port 105 a of the optical coupler 105, and the movable port of the second switch 102 is connected to the photodetector 106. Wavelengths λ ₁ and λ ₂
Of light sources 107A and 107B are connected to a second port 105b of the optical coupler 105 via a third switch 108 that can switch between them, and λ ₁ or λ ₂
Is incident on the optical connectors 104A and 104B via the optical coupler 105 and the first switch 101. Further, the optical coupler 105 emits the reflected light from the optical switch 101 to a third port 105c different from the input port 105b of the light source, and the third port 105c is connected to the second switch 102.
Is connected to the fixed port r of Each of the first and second switches 101 and 102 has a fixed port m, and these are connected without inserting an optical component therebetween. This fixed port m is used as reference light for eliminating the influence of the fluctuation of the optical power of the light sources 107A and 107B.

In the apparatus shown in FIG. 4, the movable port to which the optical coupler 105 and the photodetector 106 are connected is switched from the fixed port 1 to the port n of the first and second switches 101 and 102, respectively. The insertion loss of the n sets of optical connectors 104A and 104B can be measured. Also, the second switch 1
02 is fixed to the port r, and the connection position of the optical coupler 105 to the first switch 101 is switched from port 1 to port n, so that n sets of optical connectors 104A and 104B are connected. The return loss can be measured. Further, the present apparatus can be applied to measurement of an optical circuit component having two or more optical input ports or optical output ports, such as an optical coupler.

[0007] FIG. 5 shows that, in Section 5.2.2 of the above document,
OTDR Measurement Equipment (OTDR Measurement)
2 shows a device described as (Facility). As shown in FIG. 5, this device also has first and second switches 101 and 102 capable of switching n optical components to be measured, similarly to the above-described device. Optical connectors 104A as optical components are provided between the fixed ports 1 to n of the switches 101 and 102 via mode filters 103A and 103B and optical fibers 109A and 109B, respectively.
And 104B are connected. This apparatus can measure the insertion loss and return loss of an optical connector by using an OTDR (Opti
cal Time Domain Reflect
OTDR 110 is connected to the other end of the first switch 101 so as to be switchable. The movable port of the second switch 102 is connected to the fixed port r of the first switch 101. The optical fibers 109A and 109B
Is for increasing the time until the reflected light returns after the OTDR 110 oscillates the pulse.

In such an apparatus, in measuring the return loss, the first and second switches 101 and 102 are connected
By switching from port 1 to port n respectively, not only the return loss from the first switch 1 side can be measured, but also the first switch 1 is fixed to port r, and the second switch 102 is connected from port 1 to port n. By switching to, the return loss from the second switch 102 can also be measured.

[0009]

However, in any case of the devices shown in FIGS. 4 and 5, in order to determine the insertion loss, after the measurement of the optical connectors 104A and 104B is completed, the optical fiber is cut by the cutback method. Connectors 104A and 1
It is necessary to measure the reference optical output when there is no 04B, that is, with the optical connectors 104A and 104B removed and the optical fibers fused together.

As described above, in the prior art, automatic measurement of optical characteristics of many optical components and continuous measurement of a plurality of optical characteristic items are performed. However, in any case, the cutback method is performed when measuring the insertion loss, and there is a problem that a manpower for the cutback is indispensable during a series of measurements.

[0011] The object of the present invention has been made in view of such circumstances.
An object of the present invention is to provide an optical component inspection apparatus that automatically measures various optical characteristics of a large number of optical components without manual intervention during a series of measurements.

[0012]

A first aspect of the present invention to achieve the above object is to provide one or more optical input ports and one or more optical input ports.
Number or more of one of the optical component and an optical output port, or by connecting a plurality, various optical properties of the optical component to an optical component inspection apparatus for automatic measurement; light source and; 2 heart movable port
And a plurality of two-core fixed ports.
Select any one of the fixed ports and select 2 ports
An input port switcher connected to the two-core movable port at;
A first movable port, a second movable port, and a plurality of fixed ports;
Wherein the said fixed ports, which is connected to said optical output port of the optical component, any one the selected port first movable port or the second movable port <br/> bets from the fixed port An output port switch connected to the input port ;
Input port connected to one of the two-core fixed ports of the vessel
And the other of the two-core fixed port of the input port switcher
A first branch port connected to the optical component;
An optical splitter and a second branch port connected to the force port; and the output port optical detector coupled to the first movable port of the switch; the input port switch of the 2
A reference photodetector connected to one heart movable port; the light from the light source, the 2 heart movable of said input ports switcher
Port other or the second friendly of the output port switching unit of
An optical component inspection apparatus, comprising: a light source switcher for switching connection to a moving port.

Further, a second aspect of the present invention, in a first aspect, Bei a plurality of light sources connected to the light source switching unit
For example, the light source switch the light from any light source selected from the plurality of light sources, the said input port selector
The optical component inspection device is characterized in that the optical component inspection device is switched to the other of the two-core movable port or the second movable port of the output port switch.

[0014]

[0015] A third aspect of the present invention is the optical component inspection apparatus according to the first or second aspect, wherein the light source is at least an OTDR.

A feature of the optical component inspection apparatus according to the present invention is that, in the measurement of insertion loss, light from a light source is split into two by an optical splitter, one of the split lights is passed through an optical component to be measured, and the other is split. The point is that the insertion loss is determined by a method of measuring each optical output with a photodetector without passing light through optical components.

The method for measuring the insertion loss of the present invention will be specifically described with reference to FIG.

In the pre-measurement (FIG. 3A), the light from the light source 1 is split into two by the optical splitter 2, and the respective outputs are
First and second photodetectors 3 with no optical components connected
And 4, the value of the branching ratio r = P of the optical splitter 2
Seek ₁₀ / P _20. This is because the splitting ratio of the optical splitter 2 changes depending on the wavelength of the light source, and it is necessary to obtain the splitting ratio at all the wavelengths specified in the inspection.

In this measurement (FIG. 3B), the light source 1
Is split into two by the optical splitter 2, an optical component 5 is inserted into one of the split lights, and the outputs P1 and P2 of the _first and _second photodetectors 3 and 4 are measured. At this time,
The insertion loss α of the optical component 5 is given by equation (1).

[0020]

Α = 10 · log (rP ₂ / P ₁ ) (1) In the present invention, the first photodetector with the optical component 5 connected to the reference optical output when the optical component 5 is not present 3 and the value of the branching ratio of the optical splitter 2, there is no need to cut off the optical components during the measurement, unlike the cutback method which is a conventional measurement method.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings. However, the embodiments disclosed below are merely illustrative of the present invention and do not limit the scope of the present invention in any way. .

(Embodiment 1) FIG. 1 is a schematic view showing an apparatus according to a first embodiment of the present invention. As shown in FIG. 1, an optical component 10 having a plurality of or a plurality of input / output terminals to be measured is installed in a constant temperature layer 11. The apparatus of the present embodiment includes a plurality of optical components 10 (80 in this embodiment).
Input port switch 12 and an output port switch 13 for switching the input / output terminals of the input port switch 12 and the fixed port 12a of the input port switch 12 between the input port switch 12 and the optical component 10. And the same number of optical splitters 14 are arranged. One end of each optical splitter 14 is connected to each fixed port 12a, and one of the other branch ports is connected to the input port side of the optical component 10, respectively. The other of the branch ports of the optical splitter 14 is a reference light output port, which is connected to a plurality of (80 in this embodiment) fixed ports 15a of the reference light port switch 15. On the other hand, a plurality of (80 in this embodiment) fixed ports 13 a of the output port switch 13 are respectively connected to the output port side of the optical component 10. The device of the present embodiment has a light emitting diode (LED) light source 16 and a semiconductor laser (LD) as light sources.
A light source 17, a white light source 18, and an OTDR 19;
These light source groups are connected to the four fixed ports 2 of the light source switch 20.
0a. The light source switch 20
, A polarization controller 21 and a spectroscope 22 are connected between the LD light source 17 and the white light source 18, respectively. Here, the light source switch 20 has two movable ports 20.
b and 20 c, and one movable port 20 b is connected to the movable port 12 b of the input port switch 12. The device also includes a photodetector 24 and a reference light detector 25, which are respectively movable port 13b of output port switch 13 and reference light port switch 15.
Is connected to the movable port 15b. The output port switch 13 has a second movable port 13c in addition to the movable port 13b, and the movable port 13c is connected to the movable port 20c of the light source switch 20.

In the apparatus of this embodiment, the LED light source 16
When measuring the insertion loss or the temperature dependence of the insertion loss, the LD light source 17 and the polarization controller 21 measure the polarization dependence of the insertion loss. When measuring the wavelength dependence of
R19 is used when measuring the return loss. Further, the insertion loss, the temperature dependency of the insertion loss, the polarization dependency of the insertion loss, and the return loss can be measured at both the wavelengths of 1.31 μm and 1.55 μm. These light sources can be switched to an arbitrary one by the light source switch 20, and a desired light source is connected to the fixed port 12b of the input port switch 12 via the movable port 20b. The light source connected to the fixed port 12b is connected to the input port side of the optical component 10 connected to the arbitrarily selectable movable port 12a. The optical splitter 14 disposed between the input port switch 12 and the optical component 10 splits the light output from each movable port 12a into two, and outputs one of them to the optical component 10. The other branched light is output to each fixed port 15 a of the reference light port switch 15. Also,
The light that has passed through the optical component 10 is output to each fixed port 13 a of the output port switch 13. Light input to each fixed port 13a of the output port switch 13 and each fixed port 15a of the reference light port switch 15 are respectively transmitted via the fixed ports 13b and 15b.
The light is output to the light detector 24 and the reference light detector 25.

On the other hand, the above-mentioned light source can be connected to the output port side of the optical component 10 via the movable port 20c of the light source switch 20 and the output port switch 13. The light from the light source connected to the movable port 13c is switched to one of the fixed ports 13a and is output to the output port side of the optical component 10.

When measuring the insertion loss, the temperature dependence of the insertion loss, the polarization dependence of the insertion loss, or the wavelength dependence of the insertion loss, the light source switch 20 and the input port switch 1 are used.
2. Output port switch 13 and reference light port switch 1
5 and the light source and optical component 1 required for each measurement
The optical input port of 0 may be selected, and the optical output port of the selected optical component 10 may be connected to the photodetector 24, and the reference light port of the optical splitter 14 may be connected to the reference light detector 25. When the OTDR 19 is connected to the optical input port of the optical component 10, the return loss can be measured from the optical input port side of the optical component 10. When the OTDR 6 is connected to the optical output port of the optical component 10, the return loss of the optical component 10 can be measured. The return loss from the optical output port can be measured. OTDR
Reference numeral 19 uses a high-resolution type having an optical pulse width of 10 ns and a spatial resolution of 2 m. Also, the reflected light signal from the optical component 10 and the reflected light from the measurement system before and after do not overlap,
It is necessary to increase the distance between the optical component 10 and each measurement system to some extent. For example, the length of the optical fiber connecting the optical component 10 and the optical splitter 14 is L ₁ , the length of the optical fiber connecting the optical component 10 and the output port switch 13 is L ₂ , the optical splitter 14 and the reference optical port The length of the optical fiber connecting the switch 15 is L ₃ , and the reference light port switch 1
If the length of optical fiber connecting the 5 and a reference light detector 25 and the L _4, is desirable as a condition of the following formula (2) and (3). That is, equations (2) and (3)
As shown in FIG. _2, L ₁ and L ₂ are required to be at least about 5 m in order to distinguish the reflected light from the optical component 10 from the reflected light from the optical splitter 14 and the output port switch 13.
In order to distinguish the reflected light from the optical component 10 from the reflected light from the reference light port switch 15 and the reference light detector 25,
L ₁ is required to be larger by more than the sum of the L ₃ and L ₄ than 5 m.

[0026]

L ₁ > L ₃ + L ₄ +5 m (2) L ₂ > 5 m (3) As described above, by using the apparatus shown in the first embodiment of the present invention, a maximum of 80 optical input ports can be obtained. Loss, temperature dependence of insertion loss, polarization dependence of insertion loss, wavelength dependence of insertion loss, return loss from optical input port side, and optical output port The return loss from the side can be automatically measured. That is, first, when connecting the optical input port and the optical output port of the optical component 10 to the optical splitter 14 and the output port switch 13, respectively, only by hand, the data sheet is created from the measurement of various optical characteristics. Can be processed fully automatically. Note that the pre-measurement shown in FIG. 3A need not be performed each time the optical component 10 is replaced if the pre-measurement is performed once after the apparatus is assembled.

(Embodiment 2) FIG. 2 is a schematic view showing an apparatus according to a second embodiment of the present invention. Note that members having the same functions as those of the apparatus in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

The apparatus of the present embodiment includes an input port switch 26 instead of the input port switch 12 and the reference light port switch 15 of the first embodiment. The input port switch 26 has two cores × 80 fixed ports 20a and two cores × 1 movable port 20b. An optical input port of the optical splitter 14 and a reference light port on the branch side are respectively connected to the two fixed ports 20a in pairs, and a light source switch is connected to the two movable ports 26b. The movable port 20b of 20 and the reference light detector 25 are connected. By connecting the two movable ports 26b to the fixed ports 26a of two cores × 80 locations in units of two cores, the connection between the light source switcher 20 and the optical input port of the optical splitter 14, and the reference light detector 25 and the optical Splitter 14
, And two sets of connections can be made simultaneously. In other words, the input port switch 26 is
Of the input port switch 12 in the first embodiment of the present invention
And the function of the reference light port switch 15.

By using the second embodiment of the present invention, it is possible to automatically measure various optical characteristics of a large number of optical components as in the case of using the first embodiment of the present invention.

[0030]

As described above, since the present invention can automatically measure various optical characteristics of a large number of optical components, the demand for optical components whose optical subscriber systems are increasing with the practical use of optical subscriber systems is increasing. Inspection can be automated and speeded up. The effects are that the speed of research and development of optical components is accelerated by facilitating the inspection, and the practical use of optical subscriber systems is promoted by the reduction in the cost of optical components accompanying the reduction of inspection costs. And the like.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an apparatus according to a second embodiment of the present invention.

FIG. 3 is a principle diagram illustrating an insertion loss measuring method according to the present invention.

FIG. 4 is a schematic diagram illustrating a first example of the related art.

FIG. 5 is a schematic diagram illustrating a second example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Optical component 11 Constant temperature chamber 13 Output port switch 12, 26 Input port switch 14 Optical splitter 15 Reference light port switch 16 LED light source 17 LD light source 18 White light source 19 OTDR 20 Light source switch 21 Polarization controller 22 Spectroscope 24 Photodetector 25 Reference light detector

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akira Morinaka 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Naoyuki Atobe 1-16-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-5-240734 (JP, A) JP-A-4-366804 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 11/00-11/08 G02B 26/08

Claims (3)

(57) [Claims] 1. A one or more of one of the optical component and an optical input port and one or more optical output ports, or a plurality, optical components for automatically measuring various optical characteristics of the optical components An inspection apparatus, comprising: a light source; a two-core movable port; and a plurality of two-core fixed ports.
An input port switch for selecting an arbitrary port from a plurality of fixed ports and connecting to the two-port movable port in two-core units; a first movable port, a second movable port, and a plurality of fixed ports;
Wherein the said fixed ports, which is connected to said optical output port of the optical component, any one the selected port first movable port or the second movable port <br/> bets from the fixed port And an output port switch connected to one of the two-core fixed ports of the input port switch.
Connected to the input port connected to the input port switch.
A first branch port connected to the other of the fixation ports;
A second branch port connected to the optical input port of the optical recording component;
An optical splitter including a first optical port, a photodetector connected to the first movable port of the output port switch, and a reference light detector connected to one of the two-core movable ports of the input port switch. , the light from the light source, the 2 heart of the input port switching device
Optical component inspection apparatus characterized by comprising: a light source switch for switching connection to the other or the second movable port of said output ports switch movable port a. Wherein the optical component inspection apparatus according to claim 1 is provided with a plurality of light source connected to the source switch, the light source switch is from any light source selected from the plurality of light sources light, the 2 heart movable port of said input ports switcher
An optical component inspection apparatus, wherein the optical component inspection apparatus is switched and connected to the other one of the two or the second movable port of the output port switching device. 3. The optical component inspection apparatus according to claim 1, wherein the light source is at least an OTDR.