JPH09211383A - Multiple wavelength multiplexing/demultiplexing circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the separating and multiplexing of a light signal of one wavelength by emitting wavelength multiplex light signals after reflection these signals twice at the same optical band-pass filter. SOLUTION: The selected light signal transits the optical band-pass filter 101, is made incident on (is coupled to) a third optical collimator 106 and is emitted from an optical fiber 112. The selected light signal incident from an optical fiber 111 is made incident on a fourth optical collimator 108 through the optical band-pass filter 101 and is emitted from an optical fiber 109. The wavelength multiplex signal having the wavelength different from the selected light signal is made incident on the optical band-pass filter 101 from an optical fiber 108 and is reflected by this filter. The primary reflected light signal is made incident on (is coupled to) second and third optical collimators 104, 106. This signal is, thereupon, collimated and is made incident again on the optical band-pass filter 101, by which the signal is reflected as a secondary reflected light signal. This signal is collimated by a fourth collimator 108 and is emitted from an optical fiber 109.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength multiplex demultiplexing circuit for separating an optical signal of one wavelength from a wavelength multiplexed optical signal.

[0002]

2. Description of the Related Art Conventionally, an optical bandpass filter is used as a method of separating an optical signal of one wavelength from a wavelength multiplexed optical signal or a method of multiplexing an optical signal of a specific wavelength into a wavelength multiplexed optical signal. It has been known. FIG. 6 shows an example of the configuration of a wavelength multiplex demultiplexing circuit configured by an optical bandpass filter. In FIG. 6, reference numeral 11 denotes an optical bandpass filter having a dielectric multilayer film, which has a characteristic of transmitting only selected optical signals of a certain specific wavelength and totally reflecting all optical signals of other wavelengths.

Reference numeral 12 denotes a wavelength-multiplexed optical signal incident collimator which collimates and outputs the wavelength-multiplexed optical signal, and 13 denotes a wavelength-multiplexed optical signal incident optical fiber. Reference numeral 14 is a wavelength-multiplexed optical signal emitting collimator installed at a position where the component reflected by the optical bandpass filter 11 of the emitted light from the wavelength-multiplexed optical signal incident collimator 12 is incident, and 15 is a wavelength-multiplexed optical signal emitting collimator. It is an optical fiber.

Reference numeral 16 is a collimator 1 for injecting a wavelength division multiplexed optical signal.
Of the two emitted lights, the selected optical signal emitting collimator is provided at the position where the light of the selected optical signal wavelength component transmitted through the optical bandpass filter 11 is incident, and 17 is the selected optical signal emitting optical fiber. Reference numeral 18 denotes a collimator for inputting a selected optical signal, which is arranged so that light of a selected wavelength to be emitted from now on passes through the optical bandpass filter 11 and enters (combines) with the collimator 14 for emitting a wavelength-multiplexed optical signal. It is an optical fiber for optical signal incidence.

Of the wavelength-multiplexed optical signals incident through the wavelength-multiplexed optical signal incident optical fiber 13, the optical signals other than the selected optical signal are totally reflected by the optical bandpass filter 11 to emit the wavelength-multiplexed optical signal. The light is emitted through the optical fiber 15. On the other hand, the selected optical signal passes through the optical bandpass filter 11 and is emitted from the selected optical signal emitting optical fiber 17 via the selected optical signal emitting collimator 16.

On the other hand, the selected optical signal incident through the optical fiber 19 for injecting the selected optical signal is transmitted through the optical bandpass filter 11 and is combined as it is into the wavelength-multiplexed optical signal. It is emitted from the fiber 15. That is, with this configuration, only the selected optical signal in the wavelength-multiplexed optical signal that is incident from the wavelength-multiplexed optical signal incident optical fiber 13 and is emitted from the wavelength-multiplexed optical signal emission optical fiber 15 is separated and the selected optical signal is selected. The selected optical signal emitted from the emitting optical fiber 17 and, in place of this, entered from the selected optical signal incident optical fiber 19 is multiplexed into the wavelength division multiplexed optical signal.

By using the optical circulator 11, it is possible to construct a wavelength multiplexing polymerization demultiplexing circuit having the same function as the configuration of FIG. 6 with two collimators. FIG. 7 shows an example of the configuration of a wavelength multiplexing polymerization demultiplexing circuit using an optical circulator.

In FIG. 7, reference numeral 21 is an optical bandpass filter. 22 is a collimator for wavelength-multiplexed optical signal input / output, which is arranged so that optical signal components reflected from the optical bandpass filter 21 are coupled again, 23 is a 3-terminal optical circulator, and 24 is for wavelength-multiplexed optical signal incidence. An optical fiber, 25 is an optical fiber for outputting a wavelength-multiplexed optical signal. 26 is a collimator for inputting / outputting a selected optical signal, which is arranged so that the selected optical signal component emitted from the wavelength-multiplexed optical signal input / output collimator 22 and transmitted through the optical bandpass filter 21 is coupled, 27 is a three-terminal optical circulator, 28 is an optical fiber for selecting optical signal incidence, and 29 is an optical fiber for selecting optical signal emission.

In general, an optical circulator uses the non-reciprocity of a Faraday element to which a magnetic field is applied, and is constructed so that the incident light and the outgoing light of one terminal are coupled to different terminals.

The light incident from the wavelength-multiplexed optical signal incident optical fiber 24 is connected by the optical circulator 23 to the wavelength-multiplexed optical signal input / output collimator 22 and emitted from there. On the other hand, the wavelength-multiplexed optical signal input / output collimator 22
The incident light on is coupled to the wavelength division multiplexed optical signal emitting optical fiber 25 by the optical circulator 23 and emitted.

Similarly, the optical fiber 28 for entering the selected optical signal
The incident light is emitted from the selection optical signal input / output collimator 26, and the incident light to the selection optical signal input / output collimator 26 is output from the selection optical signal output optical fiber 29. Therefore, even using this configuration example, only the selected optical signal in the wavelength-multiplexed optical signal that is incident from the wavelength-multiplexed optical signal incident optical fiber 24 and is emitted from the wavelength-multiplexed optical signal emission optical fiber 25 is separated. Then, the selected optical signal is emitted from the optical fiber 29 for emitting the selected optical signal, and in place of this, the selected optical signal entered from the optical fiber 28 for entering the selected optical signal is multiplexed into the wavelength-multiplexed optical signal.

As described above, by using the configuration examples of FIG. 6 and FIG. 7, it is possible to configure a wavelength multiplexing polymerization demultiplexing circuit.

[0013]

SUMMARY OF THE INVENTION The present inventor has found the following problems as a result of studying the above conventional technology.

6 and 7, the selected wavelength light is separated from other wavelength-multiplexed optical signal components by one reflection of the optical bandpass filter 11. Generally, in an optical bandpass filter, it is difficult to maintain the return loss of 20 dB or more for an optical signal of the transmission wavelength. Therefore, a part of the selected wavelength light to be separated remains in the wavelength-multiplexed optical signal, and this becomes noise for the newly-multiplexed selected wavelength optical signal and deteriorates the signal.

In particular, in this case, since the wavelengths of the two optical signals are the same, there is a possibility that significant deterioration may occur due to the influence of optical interference even with a smaller noise light intensity. In order to prevent such signal degradation, it is necessary to maintain the return loss for the selected optical signal at 30 dB or more. Therefore, in the conventional circuit that separates / combines the wavelength-division-multiplexed signal with one reflection of the optical bandpass filter 11, there is a possibility that the selected optical signal to be separated / combined may be significantly deteriorated.

As a method of avoiding such a problem, it is conceivable to prepare two identical optical bandpass filters and double the reflection attenuation amount by reflecting twice.

FIG. 8 shows a configuration example based on this method. In FIG. 8, 31-1 and 31-2 are optical bandpass filters having the same reflection or transmission characteristics. Reference numeral 32 is a wavelength-multiplexed optical signal incident collimator that collimates and outputs the wavelength-multiplexed optical signal, and 33 is an optical fiber for wavelength-multiplexed optical signal incidence. 34 is a collimator for injecting wavelength-multiplexed optical signals 33
Among them, a wavelength-multiplexed optical signal emitting collimator, which is installed so that components reflected by the optical bandpass filters 31-1 and 31-2 are coupled, and 35 is a wavelength-multiplexed optical signal emitting optical fiber.

Reference numeral 36 is a collimator 3 for inputting wavelength-multiplexed optical signals.
Of the two emitted lights, the selected optical signal emitting collimator installed so that the light of the selected optical signal wavelength component transmitted through the optical bandpass filter 31-1 is coupled, and 37 is the selected optical signal emitting optical fiber. . Numeral 38 is a collimator for incidence of a selected optical signal, which is arranged so that light of a selected wavelength to be emitted from now on passes through the optical bandpass filter 31-2 and is coupled to the collimator 34 for emitting a wavelength multiplexed optical signal, and 39 is a selected optical signal. It is an optical fiber for incidence.

Of the wavelength-multiplexed optical signals incident through the wavelength-multiplexed optical signal incident optical fiber 33, the optical signals other than the selected optical signal are totally reflected by the optical bandpass filters 31-1 and 31-2. The light is emitted through the wavelength-multiplexed optical signal emitting optical fiber 35. On the other hand, the selected optical signal passes through the optical bandpass filter 31-1, and is emitted from the selected optical signal emitting optical fiber 37 via the selective optical signal emitting collimator 36.

On the other hand, the selected optical signal incident through the optical fiber 39 for injecting the selected optical signal passes through the optical bandpass filter 31-2, is multiplexed into the wavelength multiplexed optical signal, and is output for the wavelength multiplexed optical signal. It is emitted from the optical fiber 35. In this way, the wavelength demultiplexing circuit can also be configured with this configuration. Further, since the wavelength-multiplexed optical signal is reflected twice by the two optical bandpass filters, the return loss for the incident selected optical signal can be doubled as compared with the one bandpass filter. .

However, in this configuration, it is necessary to prepare two optical bandpass filters having exactly the same characteristics and strictly adjust the angles of these reflecting surfaces individually.
Therefore, there is a problem that much labor is required to manufacture the wavelength demultiplexing circuit, which is composed of one optical bandpass filter.

An object of the present invention is to provide a wavelength multiplex demultiplexing circuit for separating and multiplexing one wavelength from a wavelength multiplexed optical signal,
It is an object of the present invention to provide a technique capable of separating / combining optical signals of one wavelength without causing significant deterioration with only one optical bandpass filter.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0024]

The outline of a typical invention among the inventions disclosed in the present application will be briefly described as follows.

(1) An optical filter that transmits only light of a specific wavelength and totally reflects light of other wavelengths, a first optical collimator for making a wavelength-multiplexed optical signal enter the optical filter, A second optical collimator installed at a position where a reflected light signal emitted from the first optical collimator and reflected by the optical filter is incident, and emitted from the first optical collimator and transmitted through the optical filter. A third optical collimator installed at a position where an optical signal component is incident, and a fourth optical collimator installed at a position where a reflected optical signal emitted from the third optical collimator and reflected by the optical filter is incident.
Optical collimator, the second optical collimator, and the third optical collimator
And an optical circulator that connects the optical collimator to the optical circulator, both of which are connected via the optical circulator so that the light emitted from the second optical collimator becomes the incident light of the third optical collimator, and The emitted light of the reflected light signal from the second optical collimator of the third optical collimator is reflected by the optical filter, collimated by the fourth optical collimator and emitted to the outside, and the light of the third optical collimator is emitted. The outgoing light of the optical signal component that passes through the filter is the wavelength-multiplexing demultiplexing circuit that is externally emitted through the optical circulator.

(2) In the wavelength multiplex demultiplexing circuit according to (1), the optical filter has a plurality of optical filter regions having different transmission wavelengths, and the relative position of the optical filter and each collimator. It is equipped with a means for changing.

(3) In the wavelength multiplexing polymerization demultiplexing circuit according to (1), the optical filter has a characteristic that a transmission wavelength continuously changes according to an incident position of incident light. And means for changing the relative position of each collimator.

(4) In the wavelength multiplexing polymerization demultiplexing circuit according to (2), the optical filter has a total reflection area for reflecting light of all wavelengths, and the total reflection area of the optical filter. Adjacent to all optical bandpass filter regions.

(5) In the wavelength multiplexing polymerization demultiplexing circuit according to (3), the optical filter has a total reflection area that reflects light of all wavelengths, and the total reflection area of the optical filter. It is adjacent to all the regions corresponding to the respective wavelengths within the range of change of the transmission wavelength.

According to the above-mentioned means, when one wavelength is separated / multiplexed from the wavelength multiplexed optical signal by using the optical filter,
Separation and
It is possible to secure a sufficient return loss for an optical signal of a wavelength to be multiplexed.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings together with its embodiments (examples).

(Embodiment 1) FIG. 1 is a block diagram showing a schematic configuration of embodiment (Example) 1 of a wavelength multiplexing polymerization demultiplexing circuit of the present invention. In FIG. 1, reference numeral 101 denotes an optical bandpass filter having a dielectric multilayer film, which has a characteristic of transmitting only selected optical signals of a certain specific wavelength and totally reflecting all optical signals of other wavelengths. Reference numeral 102 denotes a first wavelength-multiplexed optical signal input for collimating and outputting the wavelength-multiplexed optical signal.
Is an optical collimator, and 103 is an optical fiber for entering a wavelength-multiplexed optical signal.

Reference numeral 104 designates a first reflected light signal incident first position which is installed at a position where the primary reflected light component reflected by the optical bandpass filter 101 of the emitted light of the first optical collimator 102 is incident (combined). 2 is an optical collimator, and 105 is an optical fiber for inputting the primary reflected optical signal obtained by collimating the primary reflected optical signal by the second optical collimator 104 to the 4-terminal optical circulator 110.

Reference numeral 106 denotes a third optical collimator installed at a position where the light of the wavelength component of the selected optical signal that has passed through the optical bandpass filter 101 of the light emitted from the second optical collimator 102 is incident (combined). , 107 for making the selected optical signal wavelength component collimated by the third optical collimator 106 incident on the four-terminal optical circulator 110, or for making the primary reflected optical signal emitted from the four-terminal optical circulator 110 the third optical collimator. An optical fiber for entering 106.

Reference numeral 108 denotes a secondary reflected light signal reflected by the optical bandpass filter 101 when the primary reflected light signal is collimated by the third optical collimator 106 and is incident on the optical bandpass filter 101 (combined). ) Is a fourth optical collimator installed at the position
Reference numeral 109 is an optical fiber for emitting the secondary reflected light signal emitted from the fourth optical collimator 108 as a wavelength division multiplexed optical signal.

110 is a four-terminal optical circulator,
It is for connecting the two so that the primary reflected optical signal from the optical fiber 105 is conducted to the optical fiber 107.

Reference numeral 111 denotes an optical fiber for inputting a selected optical signal, and its output light is a 4-terminal optical circulator 1.
The optical fiber 105 is electrically connected to the optical fiber 105. Reference numeral 112 denotes an optical fiber for emitting a selected optical signal. The emitted light of the optical fiber 107 is conducted to the optical fiber 112 via the 4-terminal optical circulator 110 and emitted from the other end of the optical fiber 112.

In the first embodiment, the selected optical signal having a wavelength that passes through the optical bandpass filter 101 among the wavelength multiplexed optical signals is the wavelength multiplexed optical signal incident optical fiber 103.
From the optical fiber 10 into the optical bandpass filter 101 through the wavelength-multiplexed optical signal collimator 102, and then passes through the optical bandpass filter 101 to enter (coupling) into the third optical collimator 106.
The light is emitted from the optical fiber 112 via the 7- and 4-terminal optical circulator 110.

Further, the selected optical signal entering from the optical fiber 111 enters the optical bandpass filter 101 from the second optical collimator 104 via the four-terminal optical circulator 110 and the optical fiber 105, and is transmitted through the optical bandpass filter 101. The light enters the optical collimator 108 of No. 4 (coupling), and the optical fiber 109
Emitted from

On the other hand, the wavelength division multiplexed optical signal having a wavelength different from that of the selected optical signal is the optical fiber 1 for the wavelength division multiplexed optical signal incidence.
03 to the optical bandpass filter 101 via the first optical collimator 102, and is reflected by the optical bandpass filter 101 to become a primary reflected optical signal. The primary reflected optical signal enters the second optical collimator 104. (Join)
Optical fiber 105, 4-terminal optical circulator 11
0 and incident (coupled) on the third optical collimator 106 via the optical fiber 107. The primary reflected light signal is collimated by the third optical collimator 106 and re-enters the optical bandpass filter 101, and is reflected by the optical bandpass filter 101 to become a secondary reflected light signal.
The light enters (combines) the fourth optical collimator 108, is collimated by the fourth optical collimator 108, and is emitted from the optical fiber 109.

Therefore, the wavelength-multiplexed optical signal is input from the first optical fiber 103 and, out of the wavelength-multiplexed optical signal output from the optical fiber 109, only the selected optical signal component is separated and output from the optical fiber 112, Also, the optical fiber 11
The selected optical signal incident from 1 is multiplexed with the wavelength-multiplexed optical signal (secondary reflected optical signal) and is emitted from the optical fiber 109, and the configuration of the present embodiment (Example) 1 is a wavelength-multiplexing demultiplexing circuit. You can see that it works as.

As is apparent from the above description, in the wavelength multiplexing / demultiplexing circuit of this Embodiment (Example) 1, the incident wavelength multiplexed optical signal is reflected twice on the same optical bandpass filter 101. Since the light is emitted from the
(DB), the attenuation amount of the selected optical signal is 2α (dB)
Can be

Therefore, even if the reflection attenuation amount of the optical bandpass filter 101 for the selected optical signal is 17 dB, the attenuation amount of 34 dB is realized by the configuration of this embodiment (example) 1 and significant signal deterioration is prevented. It becomes possible. In addition, since the configuration of the present embodiment (Example) 1 utilizes the reflection on the front surface and the back surface at the same position of one optical bandpass filter 101, it has exactly the same characteristics.
It is possible to obtain the same characteristics as those obtained by using the one optical bandpass filter 101.

In the configuration shown in FIG. 1, when the transmission wavelength of the optical bandpass filter 101 differs depending on the position within the incident plane of the filter, the wavelength of the selected optical signal can be varied by moving the filter in parallel within the incident plane. can do.

(Second Embodiment) FIG. 2 is a block diagram showing a schematic structure of an optical bandpass filter according to a second embodiment (embodiment) of a wavelength-division-multiplexing and demultiplexing circuit of the present invention. In FIG. 2, reference numeral 200 denotes an optical bandpass filter,
Reference numeral 08 is an area for forming optical bandpass filters having different transmission wavelengths. Reference numeral 209 denotes an optical filter fixing member, and one ends of the plates of the optical bandpass filter regions 201 to 208 are fixed to the optical filter fixing member 209. 21
Reference numeral 0 denotes a uniaxial optical filter driving mechanism, which drives the optical filter fixing member 209 in the vertical direction (arrow direction) to move to the boundary line between the plates of the optical bandpass filter regions 201 to 208. The optical bandpass filter regions 201 to 208 of the optical bandpass filter 200 are selected.

That is, by moving the optical filter fixing member 209, the light is converted into the optical bandpass filter region 2.
It is adjusted so as to correspond to the plates 01 to 208, and hits or reflects (passes or passes depending on the wavelength) any one of the optical bandpass filter regions 201 to 208 (any window).

2 to 5, the direction of light entering and leaving the optical bandpass filter is the direction in which light is exchanged between the front side and the far side of the paper surface.

By using the drive mechanism 210 to move the area irradiated by the incident wavelength-multiplexed optical signal, the selected optical signal to be separated / multiplexed is changed to an optical signal having a wavelength that passes through the area. Is possible.

(Third Embodiment) FIG. 3 is a block diagram showing a schematic structure of an optical bandpass filter according to a third embodiment (Example) of the wavelength-division-multiplexing and demultiplexing circuit of the present invention. In FIG. 3, reference numeral 301 denotes an optical bandpass filter whose transmission wavelength continuously changes depending on the position. Reference numeral 302 denotes an optical filter fixing member, and one end of the optical bandpass filter 301 is fixed to the optical filter fixing member 302. Reference numeral 310 denotes a uniaxial optical filter driving mechanism, and the optical filter fixing member 302
Are driven in the direction in which the transmission wavelength of the optical bandpass filter 301 changes (the arrow direction in FIG. 3), and the optical bandpass filter 301 is moved.

The wavelength of the selected optical signal can be continuously changed by moving the irradiation area of the wavelength multiplexed optical signal using the driving mechanism 310.

In the configurations shown in FIGS. 2 and 3, when the filter regions corresponding to the original selected optical signal and the new selected optical signal are not adjacent to each other, the other wavelengths are moved during the movement of the optical filter. It passes through a region that transmits multiplex optical signals. At this time, this optical signal is separated from the wavelength-multiplexed optical signal and is not emitted from the device. Therefore, in these configurations, an instantaneous interruption occurs in the wavelength multiplexed optical signal passing through the device.

(Fourth Embodiment) FIG. 4 is a block diagram showing a schematic structure of an optical bandpass filter according to a fourth embodiment (embodiment) of the wavelength-division-multiplexing and demultiplexing circuit of the present invention. In FIG. 4, 400 is an optical bandpass filter, 401 to 408 are regions forming optical bandpass filters having different transmission wavelengths, and 409 is a total reflection region formed by a metal coat or the like. Reference numeral 410 denotes a biaxial optical filter driving mechanism, and the first axial driving mechanism drives the optical filter in a direction (horizontal arrow direction in FIG. 4) perpendicular to the boundary line between the optical bandpass filter regions 401 to 408. Then, the drive mechanism of the second axis drives the filter in the direction from each of the optical bandpass filter regions 401 to 408 toward the total reflection region 409 (the vertical arrow direction in FIG. 4). Reference numeral 411 is an optical filter fixing member.

When changing the optical signal wavelength to be selected using the optical bandpass filter 400, first, the driving mechanism 4
The irradiation position of the wavelength division multiplexed optical signal is moved to the total reflection area 409 by using the second axis of 10. Next, using the first axis, the optical bandpass filter region 40 corresponding to a new selection signal wavelength while maintaining the pre-reflection state of the optical bandpass filter 400 is used.
Optical bandpass filter 4 up to positions adjacent to 1 to 408
Move 00. Then, it moves to this optical band pass filter area | region 401-408 using a 2nd axis | shaft.

By this series of switching operations, the original selected optical signal and the wavelength-multiplexed optical signal other than the new selected optical signal are kept in the total reflection state with respect to the optical bandpass filter 400.
Therefore, it is possible to change the selected optical signal to be separated / multiplexed without instantaneously interrupting the wavelength division multiplexed optical signal other than the selected optical signal during the switching operation.

(Fifth Embodiment) FIG. 5 is a block diagram showing a schematic structure of an optical bandpass filter according to a fifth embodiment (embodiment) of the wavelength-division multiplexing / demultiplexing circuit of the present invention. In FIG. 5, reference numeral 500 is an optical bandpass filter, 501 is an optical bandpass filter area in which the transmission wavelength continuously changes depending on the position, and 509 is a total reflection area made of a metal coat or the like. 510 is a biaxial optical filter drive mechanism,
The first axis drive mechanism drives the filter in the direction in which the transmission wavelength of the optical bandpass filter changes (the horizontal arrow direction in FIG. 5), and the second axis drive mechanism drives the optical bandpass filter region 5
The filter is driven in the direction from 01 to the total reflection area 509 (vertical arrow direction in FIG. 5).

When changing the wavelength of the optical signal to be selected using the optical bandpass filter 500, first, as in the case of FIG. 4, first, the irradiation position of the wavelength-multiplexed optical signal is set to the total reflection area on the second axis. Move to 509. Next, the optical bandpass filter region 50 corresponding to the new selected optical signal wavelength on the first axis
The optical bandpass filter 500 is moved to a position adjacent to 1, and the optical bandpass filter region 501 is again moved along the second axis.
Move to Also in this case, it is possible to change the selected optical signal to be separated and multiplexed without instantaneously interrupting the wavelength division multiplexed optical signal other than the selected optical signal during the switching operation.

Although the present invention has been specifically described based on the above-described embodiments (examples), the present invention is not limited to the above-described examples, and various modifications can be made without departing from the scope of the invention. Of course there is.

[0058]

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

(1) In a wavelength-multiplexing demultiplexing circuit that separates and multiplexes one wavelength from a wavelength-multiplexed optical signal, an optical signal of one wavelength can be generated without causing significant deterioration with only one optical bandpass filter. It is possible to separate and combine signals.

(2) The component of the selected optical signal to be separated is removed from the wavelength-multiplexed optical signal with a sufficient amount of attenuation, and the wavelength-division multiplex that does not cause signal deterioration due to crosstalk to the newly multiplexed selected optical signal. A branching circuit can be provided.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing a schematic configuration of an embodiment (Example) 1 of a wavelength multiplexing polymerization demultiplexing circuit of the present invention.

FIG. 2 is a block configuration diagram showing a schematic configuration of an optical bandpass filter according to an embodiment (Example) 2 of a wavelength-division-multiplexing demultiplexing circuit of the present invention.

FIG. 3 is a block diagram showing a schematic configuration of an optical bandpass filter according to a third embodiment (embodiment) of a wavelength-division-multiplexing demultiplexing circuit of the present invention.

FIG. 4 is a block configuration diagram showing a schematic configuration of an optical bandpass filter according to an embodiment (Example) 4 of a wavelength multiplex demultiplexing circuit of the present invention.

FIG. 5 is a block configuration diagram showing a schematic configuration of an optical bandpass filter according to an embodiment (Example) 5 of a wavelength-division-multiplexing demultiplexing circuit of the present invention.

FIG. 6 is a block configuration diagram showing a configuration example of a conventional wavelength multiplex demultiplexing circuit.

FIG. 7 is a block diagram showing a configuration example of a wavelength multiplex demultiplexing circuit using a conventional optical circulator.

FIG. 8 is a block configuration diagram showing a configuration example of a conventional wavelength multiplex demultiplexing circuit using two optical bandpass filters.

[Explanation of symbols]

101, 200, 400, 500 ... Optical bandpass filter, 102 ... First optical collimator, 103, 105, 1
07, 109, 111, 112 ... Optical fiber, 104 ...
Second light collimator, 106 ... Third light collimator, 1
08 ... Fourth optical collimator, 110 ... 4-terminal optical circulator, 201-208, 401-408 ... Optical bandpass filter region, 210, 310 ... 1-axis optical filter driving mechanism, 301, 501 ... Continuous transmission wavelength variable type Optical band pass filter, 409, 509 ... Total reflection area, 41
0,510 ... Biaxial optical filter drive mechanism.

Claims (5)

[Claims] 1. An optical filter which transmits only light of a specific wavelength and totally reflects light of other wavelengths, and a first optical collimator for making a wavelength-multiplexed optical signal incident on the optical filter.
A second optical collimator installed at a position where the reflected light signal emitted from the first optical collimator and reflected by the optical filter is incident, and emitted from the first optical collimator and transmitted through the optical filter. A third optical collimator installed at the position where the optical signal component to be incident is incident, and a fourth optical collimator installed at the position where the reflected optical signal emitted from the third optical collimator and reflected by the optical filter is incident. An optical collimator, and an optical circulator that connects the second optical collimator and the third optical collimator are provided, and the light emitted from the second optical collimator is transmitted through the optical circulator to the third optical collimator. Both are connected so as to become incident light, and the emitted light of the reflected light signal from the second optical collimator of the third optical collimator is reflected by the optical filter. The emitted light of the optical signal component which is collimated by the fourth optical collimator and is emitted to the outside, and which is transmitted through the optical filter of the third optical collimator is emitted from the outside via the optical circulator. Wavelength multiplex demultiplexing circuit. 2. The wavelength-multiplexed multiplexing and demultiplexing circuit according to claim 1, wherein the optical filter has a plurality of optical filter regions having different transmission wavelengths, and the relative position between the optical filter and each collimator. A wavelength multiplexing polymerization demultiplexing circuit comprising means for changing the wavelength. 3. The wavelength multiplexing polymerization demultiplexing circuit according to claim 1, wherein the optical filter has a characteristic that a transmission wavelength continuously changes depending on an incident position of incident light. And a wavelength multiplexing polymerization demultiplexing circuit comprising means for changing the relative position between the collimator and each collimator. 4. The wavelength multiplexing polymerization demultiplexing circuit according to claim 2, wherein the optical filter has a total reflection area that reflects light of all wavelengths, and the total reflection area is all of the optical filter. Adjacent to the optical bandpass filter region of the wavelength division multiplex demultiplexing circuit. 5. The wavelength multiplexing polymerization demultiplexing circuit according to claim 3, wherein the optical filter has a total reflection area that reflects light of all wavelengths, and the total reflection area is a transmission area of the optical filter. A wavelength division multiplex demultiplexing circuit characterized by being adjacent to all regions corresponding to respective wavelengths within a range of wavelength change.