JPH09105828A - Optical frequency multiplexing and demultiplexing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce loss deviation depending upon the position of a port in use and make maximum loss small while actualizing input/output characteristics of Latin square formation by making good use of only the input/output ports of the center part of a large-scale array waveguide diffraction grating optical multiplexer demultiplexer. SOLUTION: Only the input/output ports a7-a10, and b5-b11 of the center part of the large-scale array waveguide diffraction grating optical multiplexer demultiplexer are utilized to reduce the loss deviation depending upon the position of a port in use and make the maximum loss small. Here, the part corresponding to the input/output ports of the center part does not have input/output characteristics of Latin square formation irrelevantly to whether or not the array waveguide diffraction grating optical multiplexer demultiplexer has the input/output characteristics of Latin square formation, so a specific output port couple of the array waveguide type diffraction grating multiplexer demultiplexer are coupled by optical couplers 21-0 to 21-2 and then the part corresponding to the input/output ports of the center part is given the input/ output characteristics of Latin square formation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical frequency multiplexing (F
The present invention relates to an optical frequency multiplexer / demultiplexer used in a DM) network.

[0002]

2. Description of the Related Art In an FDM network, an optical frequency multiplexer / demultiplexer having a routing function in which the destination of an optical signal is determined by the difference in the optical frequency is used. In particular, M
When different optical frequencies f _{0 to} f _M-1 are used, the input / output characteristics are f _{0 to} f _M-1 , M input M output (M
If there is an optical frequency multiplexer / demultiplexer that is a Latin square of (× M), it will be very useful for the network configuration. Here, the Latin square refers to an array of n kinds of numbers or symbols so as to appear once in n rows and n columns. Table 1
Shows an example of a 4 × 4 Latin square.

[0003]

[Table 1]

[0004] Figure 3, F using optical frequency f ₀ ~f ₃
An example of a DM network is shown. In the figure, an optical frequency multiplexer / demultiplexer 1 having Latin square input / output characteristics has four inputs and four outputs, one set of which is connected to a backbone network via backbone lines 2-0 and 2-1. The remaining three sets are each a transmitting / receiving node 3.
It is connected to the input / output of -0, 3-1 and 3-2. The optical signals input to and output from the optical frequency multiplexer / demultiplexer 1 are distinguished from each other by the subscript numbers 0, 1, 2, and 3, and those from the trunk line 2-0 are represented by the subscript number 3, Transmission / reception nodes 3-0, 3-1
Those from 3-2 are represented by superscript numbers 0, 1, 2. Now
It is assumed that the optical frequency multiplexer / demultiplexer 1 has the input / output characteristics shown in Table 2. The blank in the table but is f ₃ enters as Latin square, not noted because it is not used in the example of this network.

[0005]

[Table 2]

When the optical signals ³ f ₀ to ³ f ₃ are input to the optical frequency multiplexer / demultiplexer 1 from the trunk line 2-0, the output destination is determined according to the optical frequency, and the optical signal ³ f ₀ is Transmission / reception node 3
−0, the optical signal ³ f ₁ is received by the transmission / reception node 3-2, the optical signal ³ f ₂ is received by the transmission / reception node 3-1, and the optical signal ³ f ₃ passes through as it is and the trunk line 2- Sent to 1. Optical signals ⁰ f ₁ , ⁰ f from the transmitting / receiving node 3-0
_{When 2} , ⁰ f ₀ is input to the optical frequency multiplexer / demultiplexer 1, the output destination is similarly determined according to the optical frequency, and the optical signal ⁰ f ⁰
₁ is received by the transmitting / receiving node 3-1, the optical signal ⁰ f ₂ is received by the transmitting / receiving node 3-2, and the optical signal ⁰ f ₀ is received by the trunk line 2
-1. The same applies to the optical signals transmitted from the transmission / reception nodes 3-1 and 3-2, and one-to-one transmission / reception is possible with each other.

Now, the input / output characteristic is a Latin square M ×
The M optical frequency multiplexer / demultiplexer is composed of an arrayed-waveguide grating optical multiplexer / demultiplexer and its input / output characteristics having circularity (reference: Takahashi, Okazaki, Hibino, "Array Waveguide Grating Optical frequency multiplexer / demultiplexer used ", IEICE, PST 91-42-51). FIG. 4 shows the configuration of an 8 × 8 arrayed waveguide diffraction grating optical multiplexer / demultiplexer.

In the figure, the arrayed waveguide diffraction grating optical multiplexer / demultiplexer has a structure in which an input waveguide group 11, a slab waveguide 12, an array waveguide 13, a slab waveguide 14, and an output waveguide group 15 are sequentially connected. . The other end of the input waveguide group 11 becomes the input ports I0 to I7, and the other end of the output waveguide group 15 becomes the output ports O0 to O7. Input port Ii (i = 0 to
The light that has entered the input waveguide group 11 from 7) spreads due to diffraction in the slab waveguide 12 and is guided to the arrayed waveguide 13 that is arranged perpendicular to the diffraction surface. In the arrayed waveguide 13, since the respective waveguides are sequentially lengthened with the waveguide length difference ΔL, the phase difference corresponding to the waveguide length difference ΔL is applied to the light propagating through the respective waveguides and reaching the slab waveguide 14. Is occurring. Since this phase difference varies depending on the optical frequency, when the light is focused on the input end of the output waveguide group 15 by the lens effect of the slab waveguide 14, the light is focused on different positions for each optical frequency. Therefore, light having different optical frequencies is extracted from each output port, and functions as an optical demultiplexer. Also, it similarly functions as an optical multiplexer.

The input / output characteristics of this arrayed waveguide diffraction grating optical multiplexer / demultiplexer are generally shown in Table 3. That is, when the position of the input port is shifted by one, the correspondence relationship between the optical frequency and the output port is cyclically shifted by one channel. For example, the optical frequency f ₀ with the frequency difference Δf is input to the input port I0.
When you enter a frequency multiplexed light ~f _7, the light of the light frequency f _i is demultiplexed to the output port Oi. Next, when the frequency-multiplexed light having the optical frequencies f _{1 to} f ₈ with the frequency difference Δf is input to the input port I1, the correspondence between the output port and the optical frequency is deviated by 1 and the optical frequency f _{i +} is output to the output port Oi. The light of ₁ is split. Hereinafter, it has the same input / output characteristics.

[0010]

[Table 3]

By the way, in order for the arrayed waveguide diffraction grating optical multiplexer / demultiplexer to have a Latin square input / output characteristic by itself,
It is necessary to design SR = N · Δf. For example, in Table 3, naturally, the optical path through the optical frequency _{f 8 (= f 7 + Δf} ) output port O7 input port I1 to transmit light of the arrayed waveguide grating such that the light also passes the optical frequency f ₀ Design each part of the optical multiplexer / demultiplexer. As a result, the input / output characteristics for the other input ports become similar, and the input / output characteristics for the light of the optical frequencies f _{0 to} f ₇ are Latin squares as shown in Table 4.

[0012]

[Table 4]

[0013]

However, when N becomes large, due to design restrictions and manufacturing accuracy problems,
It becomes difficult to realize an arrayed-waveguide diffraction grating optical multiplexer / demultiplexer with circularity. That is, it becomes inevitable that the peak of the transmission band comes to an optical frequency deviating from the predetermined optical frequency, and it becomes difficult to have the input / output characteristics of the Latin square.

In the arrayed waveguide diffraction grating optical multiplexer / demultiplexer, due to its structure, the light transmittance becomes higher as it passes through the input / output port located in the central portion and becomes lower as it goes through the input / output port at the end. Has characteristics (H. Takahashi, S. Suzuk
i, and I. Nishi, "Wavelength Multiplexer Based on S
iO ₂ -Ta ₂ O ₅ Arrayed-Waveguide Grating ", Journal of L
ightwave Technology, Vol.12, No.6 (1994), pp.989-99
Five). Further, the contribution of the position of the input port and the contribution of the position of the output port are independent of each other. Furthermore, in order to have circularity, when using the ports at the ends for input or output, in principle, a loss of about 3 dB (when the number of ports is odd or the number of ports is sufficiently large) occurs compared to the center. . Therefore, the loss is maximum when the input port and the output port are both end ports, and the maximum loss difference between when the input port and the output port are both central ports is about 6 dB.

However, when the number of ports is even and small, the light passing through the central port receives a loss through an optical path deviated from that when passing through the center of the slab waveguide, so the maximum loss difference is 6 dB or less. Becomes a little smaller. here,
An N × N arrayed-waveguide diffraction grating optical multiplexer / demultiplexer having circularity will be described using equations. Set the input port to Ii (i =
0 to N-1) and the output port is Oj (j = 0 to N-1). The light input to the input port Ii is output from the output port Oj.
The loss α _N (i, j) [dB] received from the

[0016]

(Equation 1)

## EQU1 ## However, A (N) is a variable dependent on N, and B is excess loss. In the following description, there is no influence of the excess loss B, so the description thereof is omitted. The minimum loss is experienced by light as it passes through mid-input and output ports, so α _N ([N /
2], [N / 2]). The maximum loss is experienced as light passes through the end input and output ports, so α _N (0,
0). However, [x] shall be the maximum integer that does not exceed x. In addition, the maximum loss difference Δα _N between ports is calculated by Δα _N = α _N (0,0) −α _N ([N / 2], [N / 2]). When N is large, α _N ([N / 2], [N
_{/ 2]) «α N (0,0} ) , and becomes an _{α N (0,0) ≒ Δα N} ≒ 6 [dB].

The arrayed-waveguide diffraction grating optical multiplexer / demultiplexer generally does not have the input / output characteristics of the Latin square, but the input / output characteristics of the Latin square are realized by providing circularity. However, if it becomes a Latin square by giving circularity, the loss varies greatly depending on which port is input and output, and the problem is that the intensity of light at output shows various values depending on the optical frequency. That is, the loss varies depending on the relationship between the optical frequency of the signal light and the port used,
In addition, a maximum loss difference of 6 [dB] occurs, making system design difficult.

Further, when N becomes large, it becomes difficult to give the orbitability after all. It is an object of the present invention to provide an optical frequency multiplexer / demultiplexer capable of reducing the loss deviation depending on the position of the port used and reducing the maximum loss while realizing the input / output characteristics of the Latin square. And

[0020]

The optical frequency multiplexer / demultiplexer of the present invention utilizes only the input / output ports at the center of a large-scale array waveguide diffraction grating optical multiplexer / demultiplexer to determine the position of the used port. The loss deviation depending on is reduced and the maximum loss is reduced. However, the arrayed waveguide grating optical multiplexer / demultiplexer does not have the input / output characteristics of the Latin square when it does not have the circularity, and when it has the circularity, it also has a part of the input / output characteristics of the Latin square. Is not a Latin square. That is, regardless of whether the arrayed waveguide grating optical multiplexer / demultiplexer has the Latin square input / output characteristics as a whole, the portion corresponding to the central input / output port does not have the Latin square input / output characteristics. Therefore, in the optical frequency multiplexer / demultiplexer of the present invention, a predetermined output port pair (or input port pair) of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer is combined with the optical multiplexer / demultiplexer (claims 1 to 4) or the optical multiplexer / demultiplexer. By combining with (claims 5 and 6), the input / output characteristic of the Latin square is realized in the portion corresponding to the input / output port in the central portion.

Here, an optical coupler or a Y-type optical multiplexer / demultiplexer is used as the optical multiplexer / demultiplexer and the optical multiplexer / demultiplexer. Further, when an optical signal is received immediately after the optical frequency multiplexer / demultiplexer, the optical signal is input so that the output from a predetermined output port pair of the arrayed waveguide grating optical multiplexer / demultiplexer is input to the same optical receiver. When the waveguide is formed, the optical waveguide serves as a light merging / branching unit.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

(Basic Embodiment) 8 × 8 having the input / output characteristics shown in Table 3
It is shown that an optical frequency multiplexer / demultiplexer having an input / output characteristic of 4 × 4 Latin square can be constructed by using the arrayed waveguide diffraction grating optical multiplexer / demultiplexer of (1). The same applies to the case of an arrayed waveguide diffraction grating optical multiplexer / demultiplexer having a circularity as shown in Table 4 (claims 3 to 6).

4 consecutive input ports I0 to I7
Select one of the input ports I1 to I4. On the other hand, output port O
7 consecutive output ports O0 to 06 of 0 to O7
Select and connect the output ports 4 distant from each other to the optical coupler. Here, the output port obtained by combining the outputs of the output port O0 and the output port O4 with the optical coupler is T0, and the output port obtained by combining the outputs of the output port O1 and the output port O5 with the optical coupler is T1. Port O2 and output port O
The output port obtained by multiplexing the respective outputs of 6 by the optical coupler is designated as T2.

Now, the optical frequencies f are input to the input ports I1 to I4.
The frequency multiplexed lights of ₄ , f ₅ , f ₆ , and f ₇ are input. The frequency-multiplexed light input to the input port I1 is demultiplexed by the arrayed waveguide diffraction grating optical multiplexer / demultiplexer, and the light of the optical frequency f ₄ is output to the output port O3 and the light of the optical frequency f ₅ is output to the output port O4. The light having the optical frequency f ₆ is output to the output port T 0 via the output port O 5 to the output port T 1, and the light having the optical frequency f ₇ is output to the output port T 2 via the output port O 6. The frequency multiplexed light input to the other input ports I2 to I4 is similarly demultiplexed and output. Therefore, the input port I
1, I2, I3, I4 and output ports O3, T0, T1,
Between T2 and T2, the input / output characteristics of the Latin square shown in Table 5 are obtained.

[0025]

[Table 5]

The light output from the output ports T0 to T2 has a predetermined loss in the optical coupler. Therefore, an attenuator that gives a loss equivalent to the loss of the optical coupler is connected to the output end of the output port O3 to make the output levels uniform. In this way, it is possible to configure the optical frequency multiplexing-demultiplexing device having an input-output characteristic of the Latin square for optical frequency f ₄ ~f _7.

(First Embodiment) FIG. 1 shows a first embodiment of an optical frequency multiplexer / demultiplexer according to the present invention. In this embodiment, N = 16, M = 4, K = 5, m = 5, and n = 7.
In the figure, reference numeral 20 is a 16 × 16 arrayed waveguide diffraction grating optical multiplexer / demultiplexer, a0 to a15 are input ports, and b0 to b0.
b15 is an output port. The optical coupler 21-0 is connected to the output ports b5 and b9 of the arrayed waveguide grating optical multiplexer / demultiplexer 20, the optical coupler 21-1 is connected to the output ports b6 and b10, and the optical coupler 21 is connected to the output ports b7 and b11. -2 is connected, and the attenuator 22 is connected to the output port b8. here,
Input port a7 of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20
˜a10 are input ports of the optical frequency multiplexing / demultiplexing device, and outputs of the attenuator 22 and the optical couplers 21-0 to 21-2 are output ports of the optical frequency multiplexing / demultiplexing device.

The input / output characteristics of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20 are shown in Table 6, and the input / output characteristics of the optical frequency multiplexer / demultiplexer of this embodiment are shown in Table 7.

[0029]

[Table 6]

[0030]

[Table 7]

The optical frequency multiplexer / demultiplexer of this embodiment is shown in Table 7.
As shown in, the input and output characteristics of the Latin square for the optical frequencies f _{4 to} f ₇ are obtained. The loss difference in such an optical frequency multiplexer / demultiplexer will be described below. This 4x
In the optical frequency multiplexer / demultiplexer of No. 4, the optical path of the minimum loss is a
7-b8, a8-b7, a8-b8, and the minimum loss α ₁₆ (7,8) (= α ₁₆ (8,7), α ₁₆ (8,8)) is α ₁₆ (7,8). ) = {(-1/16) ² + (1/16) ² } A (16) = (2/256) A (16). The maximum loss optical path is a10-b5, a7-b
11 and its maximum loss α ₁₆ (10,5) (= α ₁₆ (7,11))
Is α ₁₆ (10,5) = {(5/16) ² + (-5/16) ² } A (16) = (50/256) A (16). Therefore, the maximum loss difference is α ₁₆ (10,5) −α ₁₆ (7,8) = (48/256) A (16).

By the way, in the 16 × 16 arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20, the maximum loss optical path is, for example, a0.
-B0, and its maximum loss α ₁₆ (0,0) is α ₁₆ (0,0) = {(-15/16) ² + (-15/16) ² } A (16) = (450/256 ) It becomes A (16). Since this corresponds to 6 [dB], A (16) =
It becomes 3.41.

Therefore, the maximum loss of the optical frequency multiplexer / demultiplexer according to this embodiment is (50/256) A (16) = 0.67 [dB], and the maximum loss difference is (48/256) A (16) = It becomes 0.64 [dB].
However, the optical frequency multiplexer / demultiplexer of this embodiment has a distribution loss of 3 [dB] due to the optical couplers 21-0 to 21-2, and the maximum loss added thereto is 3.67 [dB]. On the other hand, in the optical path where the minimum loss occurs, 3 [d
The maximum loss difference is 0.64 [dB] because the attenuator 22 that gives the attenuation of B] is inserted.

The maximum loss and the maximum loss difference are obtained from the input ports a5 to a of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20.
Similar minimum values can be obtained in the configuration using 8 and the output ports b4 to b10. The optical path that gives the minimum loss of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20 is a7-b7,
There are four a7-b8, a8-b7, a8-b8, and if at least one of these is used, the predetermined effect of the present invention can be expected.

The maximum loss in the conventional 4 × 4 arrayed waveguide diffraction grating optical multiplexer / demultiplexer is α ₄ (0,0) = {(-3/4) ² + (-3/4) ² } A (4) = (18/16) A (4), which corresponds to 6 [dB], so A (4) =
It becomes 5.33. Further, the maximum loss difference is α ₄ (0,0) −α ₄ (2,2) = (18/16) A (4) − (2/16) A (4) = A (4). That is, the maximum loss is 6 [dB] and the maximum loss difference is
It becomes 5.33 [dB].

Therefore, according to the configuration of this embodiment,
The maximum loss is reduced from 6 [dB] to 3.67 [dB] by 2.33 [dB], and the maximum loss difference is changed from 5.33 [dB] to 0.64 [dB] to 4.69 [d].
B] Reduced. By the way, in the above-described embodiment, the same operation can be obtained even if the output and the input are interchanged.

In FIG. 1, the input port a of the input / output waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20 is used.
0 to a6, a11 to a15, the output ports b0 to b4 and b12 to b15 in the output waveguide group, and the waveguides and the input / output ports between the slab waveguides are related to the configuration of the present invention. Absent. Therefore, these do not necessarily have to be provided in the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20.

Further, by forming the optical couplers 21-0 to 21-2 and the attenuator 22 on the same substrate as the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20, thermal stability is obtained and connection loss is reduced. It is possible to make it smaller. In addition, the optical coupler 21
May use a Y-type optical multiplexer / splitter. Also, the attenuator 22
May be any as long as a predetermined attenuation can be obtained by bending a waveguide, a transmission blocking substance, an optical multiplexer / demultiplexer, or the like.

By the way, when N becomes a sufficiently large value,
When selecting the input / output ports of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20, the loss deviation at the central portion thereof becomes almost negligible. In this case, it is not always necessary to select a set of input / output ports that gives a minimum loss, and a set that gives a loss substantially equivalent to the minimum loss may be used.

The arrayed waveguide diffraction grating optical multiplexer / demultiplexer 2
For example, every other 0 input / output port may be selected. In that case, 1, 2,
The numbers of 3, ... Are assigned, and two output port pairs (input port pairs) for giving input / output characteristics of the Latin square are similarly determined. That is, the input / output ports and the optical frequencies of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20 do not necessarily have to be continuous, and may be selected as long as the Latin square input / output characteristics can be realized.

(Second Embodiment) On the assumption that a plurality of lights having different optical frequencies are not simultaneously output to the output port of the optical frequency multiplexing / demultiplexing device, a light receiver is arranged immediately after the optical frequency multiplexing / demultiplexing device. The second embodiment will be described. FIG.
2 shows a second embodiment of the optical frequency multiplexing / demultiplexing device of the present invention.

In the figure, the 16 × 16 arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20 is the same as that of the first embodiment, and a0
To a15 are input ports, and b0 to b15 are output ports.
The input ports of the optical frequency multiplexer / demultiplexer are the input ports a7 to a10 of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20. Output port b5 of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer 20
b9 is the light receiver 3 via the optical waveguides 30-1 and 30-2.
It is connected to 1-2. The output ports b6 and b10 are connected to the light receiver 31-3 via the optical waveguides 30-3 and 30-4. The output ports b7 and b11 are the optical waveguides 30-5 and 3
It is connected to the light receiver 31-4 via 0-6. The output port b8 is connected to the optical receiver 31-1 via the optical waveguide 30-7. Here, the optical waveguides 30-1 to 30-7 are referred to as optical path editing waveguides.

In this embodiment, with respect to the light having the optical frequencies f _{4 to} f ₇ , the outputs to the light receivers 31-1 to 31-4 with respect to the inputs to the input ports a7 to a10 are the same as in the first embodiment. The input / output characteristics of the square are shown. Further, in the present embodiment, the optical waveguides 30-1 to 30-6 are used, respectively.
The two output ports and the light receivers 31-2 to 31-4 are coupled, but unlike the case where an optical coupler is used, no merging loss occurs. Therefore, the optical waveguide 30-7 and the optical receiver 31-1
It is not necessary to insert an attenuator between and like the first embodiment.

Further, the optical waveguide 3 serving as an optical path editing waveguide
By forming 0-1 to 30-7 on the same substrate as the arrayed-waveguide diffraction grating optical multiplexer / demultiplexer 20, thermal stability can be obtained and connection loss can be reduced.

[0045]

As described above, the optical frequency multiplexer / demultiplexer according to the present invention can reduce the loss and the loss deviation while having the input / output characteristics of the Latin square.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of an optical frequency multiplexer / demultiplexer according to the present invention.

FIG. 2 is a diagram showing a second embodiment of an optical frequency multiplexer / demultiplexer according to the present invention.

FIG. 3 is a diagram showing an example of an FDM network using optical frequencies f _{0 to} f ₃ .

FIG. 4 is a diagram showing a configuration of an 8 × 8 arrayed waveguide diffraction grating optical multiplexer / demultiplexer.

[Explanation of symbols]

 1 optical frequency multiplexer / demultiplexer 2 backbone 3 transmitting / receiving node 11 input waveguide group 12, 14 slab waveguide 13 array waveguide 15 output waveguide group 20 array waveguide diffraction grating optical multiplexer / demultiplexer 21 optical coupler 22 attenuator 30 Optical waveguide 31 Light receiver

Claims (8)

[Claims] 1. The frequency of light transmitted between the waveguide i of the first waveguide group and the waveguide j of the second waveguide group is f _k (k
Is an integer represented by i + j), and a waveguide m and a waveguide m + M in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. The arrayed waveguide diffraction grating optical multiplexer / demultiplexer is provided with M-1 optical multiplexer / demultiplexers that connect each waveguide pair from the waveguide pair to the waveguide pair of the waveguide m + M-2 and the waveguide m + 2M-2. M waveguides from the waveguide n to the waveguide n + M-1 of the first waveguide group as input ports, the output of the optical multiplexer / demultiplexer and the first waveguide of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. An optical frequency multiplexer / demultiplexer, wherein the waveguide m + M-1 of the two waveguide groups is used as an output port. 2. The frequency of the light transmitted between the waveguide i of the first waveguide group and the waveguide j of the second waveguide group is f _k (k
Is an integer represented by i + j), and a waveguide m and a waveguide m + M in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. M-1 optical multiplexing / demultiplexing means for connecting each waveguide pair from the waveguide pair to the waveguide pair of the waveguide m + M-2 and the waveguide m + 2M-2, and the first of the arrayed waveguide diffraction grating optical multiplexer / demultiplexers. From the waveguide n of the first waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer, the input to the waveguide m + M−1 of the two waveguide groups and the optical coupling / decoupling means is used as an input port. Waveguide n
An optical frequency multiplexer / demultiplexer, wherein M waveguides up to + M-1 are used as output ports. 3. The frequency of light transmitted between the waveguide i of the first waveguide group and the waveguide j of the second waveguide group is f _k (k
Is the fundamental period of the arrayed waveguide grating optical multiplexer / demultiplexer,
When K is an arbitrary integer of 0 or more, k = mod [i +
j is an integer represented by j + K, N], and a waveguide m and a waveguide m + M in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. (M is an integer less than or equal to half of N), the waveguide m + M-2 and the waveguide m +
M-1 connecting each waveguide pair up to 2M-2 waveguide pair
A plurality of optical multiplexers / demultiplexers, wherein M waveguides from the waveguide n to the waveguide n + M-1 in the first waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer are used as input ports, An optical frequency multiplexer / demultiplexer, wherein the output of the optical multiplexer / demultiplexer and the waveguide m + M-1 of the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer are used as output ports. 4. The frequency of light transmitted between the waveguide i of the first waveguide group and the waveguide j of the second waveguide group is f _k (k
Is the fundamental period of the arrayed waveguide grating optical multiplexer / demultiplexer,
When K is an arbitrary integer of 0 or more, k = mod [i +
j is an integer represented by j + K, N], and a waveguide m and a waveguide m + M in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. (M is an integer less than or equal to half of N), the waveguide m + M-2 and the waveguide m +
M-1 connecting each waveguide pair up to 2M-2 waveguide pair
A plurality of optical merging / branching means, and the input to the waveguide m + M-1 and the optical merging / branching means of the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer is used as an input port. Waveguide diffraction grating optical multiplexer / demultiplexer Waveguide n to waveguide n in the first waveguide group
An optical frequency multiplexer / demultiplexer, wherein M waveguides up to + M-1 are used as output ports. 5. The frequency of light transmitted between the waveguide i of the first waveguide group and the waveguide j of the second waveguide group is f _k (k
Is the fundamental period of the arrayed waveguide grating optical multiplexer / demultiplexer,
When K is an arbitrary integer of 0 or more, k = mod [i +
j is an integer represented by j + K, N], and a waveguide m and a waveguide m + M in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. (M is an integer less than or equal to half of N), the waveguide m + M-2 and the waveguide m +
M-1 connecting each waveguide pair up to 2M-2 waveguide pair
An optical multiplexer / demultiplexer and an attenuation that is connected to the waveguide m + M-1 in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer and provides attenuation corresponding to the loss in the optical multiplexer / demultiplexer. And an M number of waveguides from the waveguide n to the waveguide n + M-1 in the first waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer as input ports. And an output of an attenuator as an output port, and m and n are a combination of waveguides selected from a first waveguide group and a second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. An optical frequency multiplexer / demultiplexer having a value including a set that gives a minimum loss of the arrayed waveguide grating optical multiplexer / demultiplexer. 6. The frequency of light transmitted between the waveguide i of the first waveguide group and the waveguide j of the second waveguide group is f _k (k
Is the fundamental period of the arrayed waveguide grating optical multiplexer / demultiplexer,
When K is an arbitrary integer of 0 or more, k = mod [i +
j is an integer represented by j + K, N], and a waveguide m and a waveguide m + M in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. (M is an integer less than or equal to half of N), the waveguide m + M-2 and the waveguide m +
M-1 connecting each waveguide pair up to 2M-2 waveguide pair
An optical multiplexer / demultiplexer and an attenuation that is connected to the waveguide m + M-1 in the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer and provides attenuation corresponding to the loss in the optical multiplexer / demultiplexer. From the waveguide n to the waveguide n + M-1 in the first waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer using the inputs of the optical multiplexer / demultiplexer and the attenuator as input ports. M waveguides are used as output ports, and m and n are combinations of waveguides selected from the first waveguide group and the second waveguide group of the arrayed waveguide diffraction grating optical multiplexer / demultiplexer. An optical frequency multiplexer / demultiplexer having a value including a set that gives a minimum loss of the arrayed waveguide grating optical multiplexer / demultiplexer. 7. The optical frequency multiplexer / demultiplexer according to claim 1, wherein the arrayed waveguide diffraction grating optical multiplexer / demultiplexer and the optical multiplexer / demultiplexer are formed on the same substrate. An optical frequency multiplexer / demultiplexer characterized by the above. 8. The optical frequency multiplexer / demultiplexer according to claim 5 or 6, wherein at least two of an arrayed waveguide diffraction grating optical multiplexer / demultiplexer, an optical multiplexer / demultiplexer, and an attenuator are formed on the same substrate. An optical frequency multiplexer / demultiplexer having the above structure.