JP2019213152A - Optical switch device - Google Patents

Abstract

To provide a low-loss optical switch device that realizes a node device that transfers an optical circuit switching type optical signal and an optical packet switching type optical signal.SOLUTION: An optical switch device provided in a node device that constitutes a network and having optical input ports PIto PIand optical output ports POto POis constituted by 1×2 optical switches 51and 51, and 2×1 optical switches 52and 52, and 2×2 optical switches 53and 53, and each of the optical switches is realized by an optical waveguide structure made of a material whose refractive index or absorption coefficient changes in the order of nanoseconds, and performs switching of both an optical circuit switching type OCS optical signal and an optical packet switching type OPS optical signal by changing the refractive index or absorption coefficient.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an optical switch device for a node device, which is an important optical component for supporting a large-capacity optical communication network.

  In recent years, high-speed and large-capacity optical communication networks have been promoted to cope with a rapid increase in communication traffic. An optical communication network is composed of a plurality of links and node devices, and research and development for high-speed and large-capacity communication is being conducted in each of them. While the link speeds up signals and multiplexes the wavelength, the node device is required to have a technology for flexibly changing the path connecting the node devices in order to realize efficient traffic. Various transmission systems have been studied as node technology, and optical switching technology that does not require optical / electrical conversion is effective in terms of power consumption and delay of network devices. Active optical transmission systems have been actively studied.

  Among them, the optical circuit switching (OCS) system and the optical packet switching (OPS) system have contradictory characteristics, and data and operations suitable for each of them are conceivable.

  In the OCS system, a link is established between specific node devices, and continuous data transmission is possible. In establishing a link, an optical path is generally set by occupying a specific wavelength band. However, since the link wavelength is occupied, transfer from other node devices is hindered. The OCS system is suitable for cases where high reliability is required because there is little packet loss, and when large amounts of data are stably transmitted.

  On the other hand, in the OPS system, connectionless transmission is possible without establishing a link between node devices. Generally, a label is given to an optical packet to be transmitted in advance, and the packet is transferred while considering collision avoidance in each node device based on the label. The OPS method is suitable for data in which traffic fluctuation of transmission data is large or data that requires low delay. As shown in Non-Patent Document 1, a flexible network based on a combination of these two methods is considered promising for future large-capacity optical communication networks, and research on node technologies for realizing them is underway.

As an optical switching technique, optical / electrical conversion is not required, and an optical signal is required to be switched at high speed as light. Such an optical switch is a thermo-optic (TO) switch configured on a planar lightwave circuit (PLC), an InP-based electroabsorption modulator (EAM), or Mach-Zehnder interference. A switch using a meter (Mach-Zehnder Interferometer: MZI), a semiconductor optical amplifier (SOA), a LiNbO ₃ phase modulator type switch, and the like have been researched and developed. As a conventional technique for forming a 1 × N optical switch, for example, a 2 × 2 optical switch element disclosed in Patent Document 1 has been proposed.

  FIG. 15 is a perspective view of a conventional 2 × 2 optical switch element. The 2 × 2 optical switch element in FIG. 15 is a directional coupler type optical switch element. On the n-InP substrate, an optical input unit (I in the figure), an optical switch unit (II), and an optical output Part (same III) and light absorption part (same IV) are provided.

More specifically, in the conventional 2 × 2 optical switch element, an i-MQW layer 5, an i-InP clad layer 4, and a p-InP clad layer 3 are sequentially laminated on an n-InP substrate 6, and p- The InP cladding layer 3 has a structure as shown in FIG. 15 and is formed in a thin line shape. Further, on both the p-InP cladding layer 3 above p-InP cladding layer 3 of one of the optical switching unit II and the light absorbing portion IV is, p ⁺ -InGaAs capping layer 2 is formed, p ⁺ -InGaAs cap On the layer 2, p-type electrodes 1, 10, and 11 are formed. An n-type electrode 7 is formed on the back surface of the n-InP substrate 6. Reference numeral 9 denotes an electrical separation groove.

  The input signal light is guided through a portion of the i-MQW layer 5 that is positioned below the p-InP cladding layer 3 formed in a thin line shape. Hereinafter, the i-MQW layer 5 positioned below the p-InP clad layer 3 provided in the light input part I, the light switch part II, the light output part III, and the light absorption part IV is referred to as an input optical waveguide and an optical switch light, respectively. These are referred to as a waveguide, an output optical waveguide, and a light absorption optical waveguide.

  The input signal light is input to one of the input optical waveguides (A or B in FIG. 15) and guided to the optical switch optical waveguide. In the optical switch optical waveguide, a desired voltage is applied between the p-type electrode 1 and the n-type electrode 7 provided in the optical switch part II, for example, due to a multiple quantum well (MQW) structure. By changing the refractive index of the optical switch optical waveguide below the p-type electrode 1 by the quantum well confined stark effect (QCSE), signal light is output from only one of the optical switch optical waveguides. That is, the optical path is switched.

  In the light absorption part IV, a desired electric field is applied between the p-type electrode 10 or 11 and the n-type electrode 7 provided in a light absorption optical waveguide different from the light absorption optical waveguide to which signal light is input. Thereby, the crosstalk light leaking from the optical switch optical waveguide is absorbed by the optical absorption optical waveguide, while the signal light output from the optical switch optical waveguide is directed to the output optical waveguide (C or D in FIG. 15). Led. Thus, by providing the light absorption part IV, an optical switch element capable of reducing the influence of leakage light from the optical switch optical waveguide is realized.

JP-A-6-59294

Hiroaki Harai et. Al., "Optical Packet and Circuit Integrated Networks and Software Defined Networking Extension," Journal of Lightwave Technology, August 15, 2014, vol. 32, no. 16, pp. 2751-2759

  Adaptation to the existing ROADM (Reconfigurable Optical Add / Drop Multiplexer) network technology is indispensable for realizing a network in which the OPS method and the OCS method are integrated. A wavelength selective switch (WSS) is used as an optical switch in ROADM of a ring network, but a node device is required to have a WSS function and a high-speed optical switch function. Since the WSS alone cannot handle both OPS and OCS signals, it is a challenge to realize a new node technology that realizes them.

  Therefore, when it is possible to cope with the OPS system, since it is necessary to switch between optical packets, the optical switch is required to have high speed. In order to enable high-speed operation of an optical switch, a structure in which carriers are injected into a semiconductor such as InP or Si and switched by an electro-optic effect is generally used. However, since a semiconductor optical waveguide has a strong optical confinement, an optical fiber is used. Connection loss and the propagation loss tends to increase due to carrier absorption and the like. The loss in the node device can be compensated by an amplifier such as an EDFA (Erbium-Doped Fiber Amplifier), but it is not preferable because it causes deterioration of signal quality, and low loss is important in the optical switch device.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a low-loss optical switch device that realizes a node device that transfers an optical signal of an optical circuit switching method and an optical signal of an optical packet switching method. .

An optical switch device according to a first invention for solving the above-mentioned problems is
In an optical switch device provided in a node device constituting a network and having a plurality of optical input ports and a plurality of optical output ports,
The optical switch device includes a plurality of optical switches,
The optical switch has an optical waveguide structure made of a material whose refractive index or absorption coefficient changes in the order of nanoseconds, and an OCS optical signal which is an optical signal of an optical circuit switching system by changing the refractive index or the absorption coefficient. And OPS optical signal which is an optical packet switching type optical signal is switched.

An optical switch device according to a second invention for solving the above-mentioned problems is as follows.
In the optical switch device according to the first invention,
The node device is a ROADM (Reconfigurable Optical Add / Drop Multiplexer) node device having a wavelength selective switch,
The optical switch device is
An add / drop process between the OCS optical signal and the OPS optical signal is arranged after the wavelength selective switch and switches the OCS optical signal and the OPS optical signal to the preset optical output port. A first optical switch unit comprising a plurality of the optical switches that perform the switching, and a plurality of the optical switches that perform the add / drop processing of the OPS optical signal by switching the OPS optical signal to the preset optical output port. And a second optical switch unit.

An optical switch device according to a third invention for solving the above-mentioned problems is as follows.
In the optical switch device according to the second invention,
A network controller that controls switching in the first optical switch unit, and a label table that controls switching in the second optical switch unit based on a label of the OPS optical signal.

An optical switch device according to a fourth invention for solving the above-mentioned problems is as follows.
In the optical switch device according to the second or third invention,
If K, L, M, and N are each an integer of 1 or more,
The first optical switch unit includes an N × (K + L) optical switch having an N × (K + L) port configuration and an (K + L) × N optical switch having a (K + L) × N port configuration,
The second optical switch unit includes an M × K optical switch having an M × K port configuration and a K × M optical switch having a K × M port configuration,
The L ports on the output side of the N × (K + L) optical switch are connected to the L ports on the input side of the (K + L) × N optical switch, and K on the output side of the N × (K + L) optical switch. Connected to the K ports on the input side of the K × M optical switch,
The K ports on the output side of the M × K optical switch are connected to the K ports on the input side of the (K + L) × N optical switch.

An optical switch device according to a fifth invention for solving the above-mentioned problems is as follows.
In the optical switch device according to the fourth invention,
If J is an integer greater than or equal to 2,
The N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, and the K × M optical switch are each a 1 × J distribution selection type optical switch having a 1 × J port configuration. Is composed of at least one 1 × J distribution selection type optical switch,
The 1 × J distribution selection type optical switch includes a 1 × J optical coupler and J light absorption gates.

An optical switch device according to a sixth invention for solving the above-mentioned problems is as follows.
In the optical switch device according to the fourth invention,
If J is an integer greater than or equal to 2,
The N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, and the K × M optical switch are each a 1 × 2 Mach-Zehnder interferometer or a plurality of 2 × 2 Mach-Zehnder interferometers. A 1 × J optical switch having a 1 × J port configuration consisting of: 1 × 2 Mach-Zehnder interferometer or at least one 1 × J optical switch,
The 1 × J optical switch connects one of two ports on the input side of the subsequent 2 × 2 Mach-Zehnder interferometer to each of the two ports on the output side of the previous 2 × 2 Mach-Zehnder interferometer, A plurality of the 2 × 2 Mach-Zehnder interferometers are connected in multiple stages in a tree shape.

An optical switch device according to a seventh invention for solving the above-mentioned problems is as follows.
In the optical switch device according to any one of the fourth to sixth inventions,
A light absorption gate is provided after the N × (K + L) optical switch.

An optical switch device according to an eighth invention for solving the above-mentioned problems is as follows.
In the optical switch device according to any one of the fourth to seventh inventions,
Between the N × (K + L) optical switch and the (K + L) × N optical switch, between the N × (K + L) optical switch and the K × M optical switch, and between the M × K optical switch and the (K + L) × N optical switches are connected to each other by an optical waveguide, and an optical waveguide having an intersection with another optical waveguide is used in some of the optical waveguides.
The N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, the K × M optical switch, and the optical waveguide are monolithically integrated on the same chip.

An optical switch device according to a ninth invention for solving the above-mentioned problems is as follows.
In the optical switch device according to any one of the fourth to seventh inventions,
Between the N × (K + L) optical switch and the (K + L) × N optical switch, between the N × (K + L) optical switch and the K × M optical switch, and between the M × K optical switch and the The (K + L) × N optical switch is connected to each other by an optical waveguide, and the N × (K + L) optical switch and the (K + L) × N optical switch are arranged so that all the optical waveguides do not cross each other. , Arranging the M × K optical switch and the K × M optical switch,
The N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, the K × M optical switch, and the optical waveguide are monolithically integrated on the same chip.

An optical switch device according to a tenth invention for solving the above-mentioned problems is
In the optical switch device according to the eighth or ninth invention,
All of the optical input port and the optical output port of the optical switch device are arranged at one end of the chip.

  According to the present invention, it is possible to provide a low-loss optical switch device that realizes a node device that transfers an optical signal of an optical circuit switching method and an optical signal of an optical packet switching method.

It is a block diagram which shows the 1 * 2 optical switch which consists of a distribution selection type | mold optical switch used for the optical switch apparatus based on this invention. It is a block diagram which shows the 1 * 2 optical switch which consists of a MZI type | mold optical switch used for the optical switch apparatus which concerns on this invention. 3 is a graph showing the transmittance with respect to an applied voltage in a light absorption gate of the distribution selection type optical switch shown in FIG. 1. FIG. 3 is a graph showing a transmittance with respect to an injection current in each optical output port of the MZI type optical switch shown in FIG. 2. FIG. It is sectional drawing which shows the structure of the optical waveguide of the optical switch shown in FIG.1 and FIG.2. It is a block diagram which shows an example (Example 1) of embodiment of the optical switch apparatus which concerns on this invention. It is a block diagram which shows the 2 * 2 optical switch which consists of a MZI type | mold optical switch used for the optical switch apparatus based on this invention. It is a block diagram which shows the 2 * 2 optical switch which consists of several distribution selection type | mold optical switches used for the optical switch apparatus which concerns on this invention. It is a block diagram which shows another example (Example 2) of embodiment of the optical switch apparatus which concerns on this invention. It is a block diagram which shows the modification of the optical switch apparatus shown in FIG. It is a block diagram which shows another example (Example 3) of embodiment of the optical switch apparatus which concerns on this invention. It is a block diagram which shows another example (Example 4) of embodiment of the optical switch apparatus which concerns on this invention. It is a block diagram which shows another example (Example 5) of embodiment of the optical switch apparatus which concerns on this invention. It is a block diagram which shows another example (Example 6) of embodiment of the optical switch apparatus which concerns on this invention. It is a perspective view which shows the conventional 2 * 2 optical switch element.

  A high-speed optical switch used for switching an OPS optical signal (hereinafter referred to as an OPS optical signal) will be described. As the switching mechanism, the distribution selection type optical switch 20 shown in FIG. 1 or the MZI type optical switch 30 shown in FIG. 2 is used. These can also be used for switching of OCS optical signals (hereinafter referred to as OCS optical signals).

In the distribution selection type optical switch 20 of FIG. 1, the input light input from the optical input port PI is divided into two light beams using a 1 × 2 optical coupler 21 which is a multi-mode interference (MMI) optical coupler. The waveguides 22 ₁ and 22 ₂ are branched, and the two optical waveguides 22 ₁ and 22 ₂ are connected to the light absorption gates 23 ₁ and 23 ₂ of the respective optical output ports PO ₁ and PO ₂ .

As will be described later, the light absorption gates 23 ₁ and 23 ₂ have an n-InP substrate, an n-InP lower cladding layer, an InGaAsP core layer, a p-InP upper cladding layer, and a p ⁺ -InGaAs cap layer. In the light absorption gates 23 ₁ and 23 ₂ , the n-type electrode provided on the n-InP substrate is grounded (potential = 0 V), and the p-type electrode provided in each of the light absorption gates 23 ₁ and 23 ₂ is minus. When a voltage is applied, the absorption edge in the InGaAsP core layer shifts due to the Franz-Keldysh (FK) effect, and the absorption coefficient at the wavelength of the signal light propagating through the light absorption gates 23 ₁ and 23 ₂ increases.

In this way, by controlling the voltage applied to the light absorption gate 23 ₁ or 23 ₂ , the light of the optical waveguide 22 ₁ or 22 ₂ that does not require output is absorbed by the light absorption gate 23 ₁ or 23 _2. Thus, switching can be performed. Here, SOA or the like may be used for the EAM used as the light absorption gate.

In the MZI type optical switch 30 shown in FIG. 2, a 1 × 2 optical coupler 31 which is an MMI optical coupler similar to FIG. 1 is used to input light input from the optical input port PI into two optical waveguides 32 ₁ and 32 _2. The input light branched into two is subjected to a phase difference due to phase modulation controlled by the control electrodes 33 ₁ and 33 _{2 in the} two optical waveguides 32 ₁ and 32 ₂ , and then the MMI optical coupler. They are recombined using a certain 2 × 2 optical coupler 34.

In this case, if the phase difference between the _two optical waveguides 32 ₁ and 32 ₂ is ± nπ due to the interference effect, the light is output from _{one of} the optical output ports PO _{1 and} PO ₂ and ± (2n + 1) π / If it is 2, the light is output from the other of the optical output ports PO _{1 and} PO ₂ . Note that n is an integer of 0 or more. Therefore, if a phase modulation region is arranged and controlled in one of the optical waveguides 32 ₁ or 32 ₂ , a 1 × 2 switching operation can be obtained.

In order to obtain the above-described phase modulation, the refractive indexes of the optical waveguides 32 ₁ and 32 ₂ may be changed. In an InP optical waveguide, the refractive index of the optical waveguide is changed using the FK effect or QCSE effect due to voltage application or the plasma effect due to current injection. In the LN optical waveguide, the optical waveguide is affected using the Pockels effect due to voltage application. If the refractive index is changed, a switching operation can be performed. A directional coupler or the like may be used as the MMI optical coupler that divides the light intensity into two equal parts.

In the case of the distribution selection type optical switch 20 shown in FIG. 1, as shown in FIG. 3, with respect to the light absorption gates 23 ₁ and 23 ₂ , an extinction ratio of 20 dB or more with an applied voltage of −3 V and an applied voltage of −7 V Thus, an extinction ratio of 40 dB or more can be obtained.

In the case of the MZI type optical switch 30 shown in FIG. 2, as shown in FIG. 4, when the current injected into the _two arm optical waveguides 32 ₁ and 32 ₂ is 0 mA, the input signal light is the light in FIG. Output to the output port PO ₁ side. When a current is injected into _{one of} the control electrodes 33 ₁ and 33 ₂ , the refractive index of the arm optical waveguide that is injected changes, and the phase of the propagating light changes. When the injection current into the arm optical waveguide is about 5 mA, the output from the optical output port PO ₁ is minimum, and the optical output to the optical output port PO ₂ is maximum. In this case, the ratio of the light output to the optical output and the optical output port PO ₁ to the optical output port PO ₁ are obtained at least 20 dB.

  In the case of a distribution selection type optical switch, not only the 1 × 2 distribution selection type optical switch 20 but also the switching to a large number of optical output ports is possible by increasing the number of branches. In this case, when J is an integer of 2 or more, a 1 × J optical switch having a 1 × J port configuration includes a 1 × J optical coupler and J light absorption gates.

  In the case of the MZI type optical switch, not only the one-stage MZI type optical switch 30 but also a 2 × 2 MZI type optical switch 60 to be described later is connected in multiple stages in a tree shape, so that a large number of optical output ports can be connected. Switching is possible. In this case, in the case of the 1 × J optical switch, the input side of the rear 2 × 2 MZI optical switch 60 is connected to each of the two ports on the output side of the front 2 × 2 MZI optical switch 60. One of the two ports is connected.

  Next, a manufacturing method of the distribution selection type optical switch 20 to be an optical switch capable of high speed operation will be described.

First, an n-InP lower clad layer, a bulk i-InGaAsP core layer having a 1.4Q composition of 0.3 μm thickness, a p-InP upper clad layer, and a p ⁺ -InGaAs cap layer are formed on an n-InP substrate. Grow by vapor phase growth method (Metal Organic Vapor Phase Epitaxy: MOVPE).

Next, an input optical waveguide having a high-mesa optical waveguide structure, a 1 × 2 optical coupler 21, optical waveguides 22 ₁ and 22 ₂ , light absorption gates 23 ₁ and 23 ₂ and an output optical waveguide are collectively formed by photolithography and dry etching. To do. After forming the optical waveguide structure, benzocyclobutene (BCB), which is an organic material that can be embedded in a local region and has excellent planarization, is applied by spin coating, and an O ₂ / C ₂ F ₆ mixed gas is used. Etching back is performed by RIE (Reactive Ion Etching) until the substrate surface before embedding (the uppermost surface of the substrate) is exposed, and the substrate surface is flattened.

Finally, a p-type electrode is formed on the light absorption gate 23 _{1, the} light absorption gate 23 ₂ , and the p ⁺ -InGaAs cap layer of the 1 × 2 coupler 21, and the n-InP substrate rear surface or the optical waveguide structure of the substrate An n-type electrode is formed in a region where is not formed.

In the above manufacturing method, MOVPE growth and formation of an optical waveguide structure can be performed at once. Further, unlike the conventional optical switch element shown in FIG. 15, the n-InP upper cladding layer and the p ⁺ -InGaAs cap layer are removed between the 1 × 2 optical coupler 21 and the light absorption gates 23 ₁ and 23 _2. The process to do becomes unnecessary. Therefore, it is possible to provide an optical switch that has a simple manufacturing method, does not deteriorate optical characteristics, and has extremely low optical crosstalk.

FIG. 5 shows a cross-sectional view of the optical waveguide structure. In FIG. 5, reference numeral 41 denotes an n-InP substrate, reference numeral 42 denotes an n-InP lower cladding layer, reference numeral 43 denotes an InGaAsP core layer, reference numeral 44 denotes a p-InP upper cladding layer, and reference numeral 45 denotes a p ⁺ -InGaAs cap layer. . In this embodiment, as shown in FIG. 5, an InGaAsP core layer 43 having a thickness of 0.3 μm and a width of 1.5 μm and a 1.4Q composition is used. These design values are important parameters that determine the optical characteristics of the optical switch.

In order to operate with an input signal light wavelength of, for example, 1.53 μm to 1.57 μm and realize an operation with low loss, high speed, and low power consumption, it is preferable that the following conditions are satisfied.
(1) The thickness of the InGaAsP core layer 43 is a single mode waveguide condition with respect to the input signal light, and is a condition having sufficient light confinement in the InGaAsP core layer 43, and is 0.1 μm to 0. A range of 4 μm is desirable.
(2) The width of the InGaAsP core layer 43 is a single mode waveguide condition with respect to the input signal light, and is preferably in the range of 0.8 μm to 3 μm.
(3) The composition of the InGaAsP core layer 43 is 1.3Q to 1.5Q, and each electrode length is preferably in the range of 100 μm to 2000 μm in the case of EAM and 50 μm to 1000 μm in the case of MZI.

In the optical switch according to this embodiment, the bulk layer is used as the InGaAsP core layer 43 of the light absorption gates 23 ₁ and 23 ₂ , but an MQW structure may be used. In that case, quenching can be performed with high efficiency by the QCSE effect. Further, although the optical waveguide structure is a high mesa optical waveguide structure, other structures such as a ridge type optical waveguide structure may be manufactured. Alternatively, an embedded optical waveguide structure or a rib optical waveguide structure in which both sides of the InGaAsP core layer 43 are embedded with a semiconductor may be used.

  Further, although the optical switch in this embodiment has been described using an InP-based compound semiconductor, a GaAs-based compound semiconductor may be used. The same can be realized by using a material system such as a silicon fine wire optical waveguide. Optical waveguide structures using these materials can change the refractive index or absorption coefficient in the order of nanoseconds, and such high-speed changes enable high-speed switching of OCS optical signals and OPS optical signals.

  Hereinafter, some embodiments of the optical switch device according to the present invention using a plurality of the optical switches described above will be described. The optical switch device according to the present invention is provided in a ROADM node device of a network that uses both an OCS optical signal and an OPS optical signal. The ROADM node device has a WSS, and the optical switch device according to the present invention is arranged at a stage subsequent to the WSS of the node device.

[Example 1]
FIG. 6 shows an optical switch device according to this embodiment. Here, as an example, an optical switch device having _four optical input ports PI _{1 to} PI ₄ and four optical output ports PO _{1 to} PO ₄ is assumed to be capable of simultaneously transferring an OCS optical signal and an OPS optical signal. . For add / drop between an OCS optical signal and an OPS optical signal, two 1 × 2 optical switches (hereinafter referred to as 1 × 2SW) 51 ₁ and 51 _{2 and} a 2 × 1 optical switch (hereinafter referred to as 2 × 1SW) 52 ₁ , 52 ₂ (first optical switch unit), and for add / drop of an OPS optical signal, two 2 × 2 optical switches (hereinafter referred to as 2 × 2SW) 53 ₁ and 53 ₂ are used (first). 2 optical switch section).

The optical input port PI ₁ is connected to the input side of the 1 × 2 SW 51 ₁ , the optical input port PI ₂ is connected to the input side of the 1 × ₂ SW 51 ₂ , and the optical input ports PI ₃ and PI ₄ are 2 × 2 SW 53 _1. Is connected to the input side. The optical output port PO ₁ is connected to the output side of the 2 × ₁ SW 52 ₁ , the optical output port PO ₂ is connected to the output side of the 2 × 1 SW 52 ₂ , and the optical output ports PO ₃ and PO ₄ are 2 × 2SW53 is connected to the _second output side.

Then, 1 one of the optical output port of × 2SW51 ₁ is the optical fiber 54 ₁ is connected to the 2 × 1SW52 ₁ of one of the optical input port, 1 × 2SW51 ₁ of the other light output port, the optical fiber 54 ₂ is connected to one optical input port of the 2 × 2 SW 53 ₂ . Also, 1 × 2SW51 ₂ of one of the optical output port, the optical fiber _543, is connected to the ₂ × 1SW52 2 of one of the optical input port, 1 × 2SW51 ₂ of the other light output port, the optical fiber 54 ₄ is connected to the other optical input port of the 2 × 2 SW 53 ₂ . Further, the 2 × 2SW53 ₁ of one of the optical output port, the optical fiber 54 _5, is connected to the 2 × 1SW52 ₁ of the other optical input port, the 2 × 2SW53 ₁ of the other light output port, the optical fiber the 54 _6, are connected to the ₂ × 1SW52 2 of the other optical input port.

Thus, in the optical switch device of the present embodiment, each switching element is an individual chip or module, and these are connected by the optical fibers 54 _{1 to} 54 ₆ . Note that 1 × 2 SWs and 2 × 1 SWs may be the same chip or module.

By adopting the distribution selection type optical switch 20 shown in FIG. 1 or the MZI type optical switch 30 shown in FIG. 2 for the above 1 × 2 SW 51 ₁ , 51 ₂ and 2 × ₁ SW 52 ₁ , 52 ₂ , the operation speed can be increased. It is possible to switch between the OCS optical signal and the OPS optical signal. In addition, the above 2 × 2 SW 53 ₁ and 53 ₂ adopt the MZI type optical switch 60 as shown in FIG. 7 and the 2 × 2 SW 70 as shown in FIG. 8 to enable high-speed OPS optical signal processing. And The MZI type optical switch 60 shown in FIG. 7 and the 2 × 2 SW 70 shown in FIG. 8 will be described below.

The MZI type optical switch 60 shown in FIG. 7 has a configuration in which the MZI type optical switch 30 shown in FIG. 2 is expanded to 2 × 2. Specifically, the MZI type optical switch 60 is a 2 × 2 light which is an MMI optical coupler in which optical input ports PI ₁ and PI ₂ are connected to the input side and optical waveguides 62 ₁ and 62 ₂ are connected to the output side. a coupler 61, a control electrode 63 _1, 63 ₂ each provided on the optical waveguide 62 _1, 62 _2, the optical waveguide 62 _1, 62 ₂ is connected to the input side, the optical output port PO _1, PO to the output side ₂ has a 2 × 2 optical coupler 64 which is an MMI optical coupler to which ₂ is connected.

Further, 2 × 2SW70 shown in FIG. 8 is a configuration that is connected face to face by the distributor selective optical switch 20 broadcast-and-select optical switch 71 _{1-71 4} having the same configuration as the 2: 2 shown in Figure 1. Specifically, the optical input port PI ₁ is connected to the input side of the distribution selection type optical switch 71 ₁ , and the optical input port PI ₂ is connected to the input side of the distribution selection type optical switch 71 ₂ . Further, the optical output port PO ₁ is connected to the output side of the distributor selection optical switch 71 _3, optical output port PO ₂ is connected to the output side of the distributor selection optical switch 71 _4.

Then, one of the optical output port of broadcast-and-select optical switch 71 _1, the optical waveguide 72 ₁ is connected to one of the optical input port of broadcast-and-select optical switch 71 _3, other one of the distribution selective optical switch 71 ₁ the optical output port, the optical waveguide 72 ₂ is connected to one of the optical input port of broadcast-and-select optical switch 71 _4. Also, one of the optical output port of broadcast-and-select optical switch 71 _2, the optical waveguide 72 _3, is connected to the other optical input port of broadcast-and-select optical switch 71 _3, broadcast-and-select optical switch 71 ₂ Nomou one optical output port, the optical waveguide 72 ₄ is connected to the other optical input port of broadcast-and-select optical switch 71 _4.

Then, high-speed switching between the OCS optical signal and the OPS optical signal is performed by 1 × 2 SW 51 ₁ , 51 ₂ and 2 × ₁ SW 52 ₁ , 52 ₂ . Specifically, the 1 × 2 SW 51 ₁ , 51 ₂ and the 2 × ₁ SW 52 ₁ , 52 ₂ distribute the OCS optical signal and the OPS optical signal according to the control of the network controller (not shown), and set the optical output port set in advance. Switching to. Since the OCS optical signal that does not drop is cut and transferred as it is, it can be transferred without delay or loss.

Further, high-speed switching of the OPS optical signal is performed by 2 × 2 SWs 53 ₁ and 53 ₂ . Specifically, the label of the OPS optical signal is read immediately before 2 × 2 SW 53 ₁ and 2 × 2 SW 53 ₂ , and switching to a preset optical output port is performed based on the label table.

That is, in the WSS-based ROADM node device, the optical switch device according to the present embodiment includes 1 × 2 SW 51 ₁ , 51 ₂ and 2 × ₁ SW 52 ₁ , 52 ₂ dedicated for add / drop between the OCS optical signal and the OPS optical signal. The high-speed optical switch described above is used for these. With such a configuration, it is possible to handle both the OCS optical signal and the OPS optical signal without giving any disadvantage to the OCS optical signal. Furthermore, by optimizing the number of ports of each optical switch and the connection of optical fibers to the network configuration, it is possible to establish a node technology that suppresses loss, which is a drawback of high-speed optical switches.

[Example 2]
FIG. 9 shows an optical switch device according to this embodiment. Here, similarly to the optical switch device shown in the first embodiment, the optical switch device has four optical input ports PI _{1 to} PI ₄ and four optical output ports PO _{1 to} PO ₄ , and the OCS optical signal and the OPS light are used. It is assumed that signals can be transferred simultaneously. For add / drop between the OCS optical signal and the OPS optical signal, _two of 1 × ₂ SW 51 ₁ , 51 ₂ and two of 2 × ₁ SW 52 ₁ , 52 ₂ are used, and for add / drop of the OPS optical signal, 2 × Two 2SWs 53 ₁ and 53 ₂ are used. That is, the optical input ports PI _{1 to} PI ₄ , the optical output ports PO _{1 to} PO ₄ , 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ , 2 × 2 SW 53 ₁ , 53 ₂ are described in the first embodiment. The configuration is the same as that of the illustrated optical switch device, and therefore, the same reference numerals are given in FIG.

In the optical switch device according to the present embodiment, 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are integrated on one chip as switching elements, and each switching element They are connected by an optical waveguide having a structure equivalent to that of the optical waveguide shown in FIG. Specifically, on the same chip substrate 81, and a _{1 × 2SW51 1, 51 2,} 2 × 1SW52 1, 52 2 and ₂ × 2SW53 _1, 53 2 optical waveguide 82 _{1-82 6} with monolithically integrated, The optical switches are connected by optical waveguides 82 _{1 to} 82 ₆ . As the chip substrate 81, for example, an n-InP substrate shown in FIG. 5 may be adopted.

Specifically, 1 one of the optical output port of × 2SW51 ₁ is the optical waveguide 82 ₁ is connected to the 2 × 1SW52 ₁ of one of the optical input port, the 1 × 2SW51 ₁ of the other optical output port, The optical waveguide 82 ₂ is connected to one optical input port of the 2 × 2 SW 53 ₂ . Also, 1 × 2SW51 ₂ of one of the optical output port, the optical waveguide 82 _3, is connected to the ₂ × 1SW52 2 of one of the optical input port, 1 × 2SW51 ₂ of the other light output port, the optical waveguide 82 ₄ is connected to the other optical input port of the 2 × 2 SW 53 ₂ . Further, the 2 × 2SW53 ₁ of one of the optical output port, the optical waveguide 82 _5, is connected to the 2 × 1SW52 ₁ of the other optical input port, the 2 × 2SW53 ₁ of the other light output port, the optical waveguide the 82 _6, are connected to the ₂ × 1SW52 2 of the other optical input port.

By adopting the distribution selection type optical switch 20 shown in FIG. 1 and the MZI type optical switch 30 shown in FIG. 2 for the above 1 × 2 SW 51 ₁ , 51 ₂ and 2 × ₁ SW 52 ₁ , 52 ₂ as well, it is possible to increase the speed. It is possible to switch between the OCS optical signal and the OPS optical signal. Further, the above-described 2 × 2 SWs 53 ₁ and 53 ₂ also employ the MZI type optical switch 60 shown in FIG. 7 and the 2 × 2 SW 70 shown in FIG. 8 to enable high-speed OPS optical signal processing. . The optical switches employed for the ₁ × ₂ SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 _2, and 2 × 2 SW 53 ₁ , 53 ₂ are the same in the _third to fifth embodiments described later.

  In this way, in the optical switch device according to the present embodiment, the add / drop of the OPS optical signal can be realized on the same chip in addition to the add / drop of the OCS optical signal and the OPS optical signal. Miniaturization is possible. Further, regarding the connection loss with the optical fiber that is the loss source of the optical switch device, it is not necessary to connect the switching elements with the optical fiber, so that a reduction in loss can be expected.

Further, as shown in FIG. 10, by adding EAMs 83 _{1 to} 83 ₄ to be light absorption gates after the 1 × 2SWs 51 ₁ and 51 ₂ on the add side, specifically, 1 × 2SWs 51 ₁ and 51 ₂ are added. By adding EAM 83 _{1 to} 83 ₄ to each of the optical output ports, switching can be performed while suppressing crosstalk to other ports. The same applies to the light absorption gates (for example, the above EAMs 83 _{1 to} 83 ₄ ) in Examples 3 to 5 described later.

Then, high-speed switching between the OCS optical signal and the OPS optical signal is performed by 1 × 2 SW 51 ₁ , 51 ₂ and 2 × ₁ SW 52 ₁ , 52 ₂ . Specifically, the 1 × 2 SW 51 ₁ , 51 ₂ and the 2 × ₁ SW 52 ₁ , 52 ₂ distribute the OCS optical signal and the OPS optical signal according to the control of the network controller (not shown), Perform switching. At this time, the OCS optical signal is also labeled similarly to the OPS optical signal, and the OCS optical signal and the OPS optical signal are added / dropped accordingly. Since the OCS optical signal that does not drop is cut and transferred as it is, it can be transferred without delay or loss.

Further, high-speed switching of the OPS optical signal is performed by 2 × 2 SWs 53 ₁ and 53 ₂ . Specifically, at 2 × 2SW53 ₁ and ₂ × 2SW53 2 just before reading the label of the OPS optical signal, performs switching on the basis of the label table.

That is, in the WSS-based ROADM node device, the optical switch device according to the present embodiment includes 1 × 2 SW 51 ₁ , 51 ₂ and 2 × ₁ SW 52 ₁ , 52 ₂ dedicated for add / drop between the OCS optical signal and the OPS optical signal. The high-speed optical switch described above is used for these. With such a configuration, although label information needs to be added, it is possible to handle both the OCS optical signal and the OPS optical signal without giving a disadvantage to the OCS optical signal. Furthermore, by optimizing the number of ports of each optical switch and the connection of optical waveguides to the network configuration, it is possible to establish a node technology that suppresses the loss that is a disadvantage of the high-speed optical switch.

[Example 3]
FIG. 11 shows an optical switch device according to this embodiment. Here, similarly to the optical switch device shown in the first embodiment, the optical switch device has four optical input ports PI _{1 to} PI ₄ and four optical output ports PO _{1 to} PO ₄ , and the OCS optical signal and the OPS light are used. It is assumed that signals can be transferred simultaneously. For add / drop between the OCS optical signal and the OPS optical signal, _two of 1 × ₂ SW 51 ₁ , 51 ₂ and two of 2 × ₁ SW 52 ₁ , 52 ₂ are used, and for add / drop of the OPS optical signal, 2 × Two 2SWs 53 ₁ and 53 ₂ are used. In other words, the optical input ports PI _{1 to} PI ₄ , the optical output ports PO _{1 to} PO ₄ , 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ , 2 × 2 SW 53 ₁ , 53 ₂ are arranged. Except for this, the configuration is the same as that of the optical switch device shown in the first embodiment. Therefore, the same reference numerals are given in FIG.

Also in the optical switch device according to the present embodiment, 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are integrated on one chip as switching elements, and each switching element They are connected by an optical waveguide having a structure equivalent to that of the optical waveguide shown in FIG. Specifically, the optical waveguides 84 _{1 to} 84 ₆ are monolithically integrated on the same chip substrate 81 together with ₁ × ₂ SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ , The optical switches are connected by optical waveguides 84 _{1 to} 84 ₆ .

Specifically, 1 one of the optical output port of × 2SW51 ₁ is the optical waveguide 84 ₁ is connected to the 2 × 1SW52 ₁ of one of the optical input port, the 1 × 2SW51 ₁ of the other optical output port, The optical waveguide 84 ₂ is connected to one optical input port of the 2 × 2 SW 53 ₂ . Also, 1 × 2SW51 ₂ of one of the optical output port, the optical waveguide 84 _3, is connected to the ₂ × 1SW52 2 of one of the optical input port, 1 × 2SW51 ₂ of the other light output port, the optical waveguide 84 ₄ is connected to the other optical input port of the 2 × 2 SW 53 ₂ . Further, the 2 × 2SW53 ₁ of one of the optical output port, the optical waveguide 84 _5, is connected to the 2 × 1SW52 ₁ of the other optical input port, the 2 × 2SW53 ₁ of the other light output port, the optical waveguide the 84 _6, are connected to the ₂ × 1SW52 2 of the other optical input port.

The 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are connected to each other so that the optical waveguides 84 _{1 to} 84 ₆ connecting them do not cross each other. Are arranged adjacent to each other.

For example, ₁ × 2SW51 1 and 2 × 2SW53 ₂ which are connected by the optical waveguide 84 ₂ are arranged adjacently, 2 × 2SW53 ₂ and 1 × 2SW51 ₂ which are connected by the optical waveguide 84 ₄ are arranged adjacent to each other, Further, 2 × 1SW52 ₁ and 2 × 2SW53 ₁ connected by the optical waveguide 84 ₅ are arranged adjacent to each other, and 2 × 2SW53 ₁ and 2 × 1SW52 ₂ connected by the optical waveguide 84 ₆ are arranged adjacent to each other. Yes. The 1 × 2 SW 51 ₁ and the 2 × ₁ SW 52 ₁ connected by the optical waveguide 84 ₁ are arranged at different ends, but it can be said that they are arranged adjacent to each other on the connection, and the optical waveguide 84 _3. in even 1 × 2SW51 ₂ and ₂ × 1SW52 2 to be connected are disposed on different ends from each other, connected on can be said to be disposed adjacent.

Due to the arrangement described above, the arrangement of the optical input ports PI _{1 to} PI ₄ and the optical output ports PO _{1 to} PO ₄ is different from that of the second embodiment. Specifically, in Example 2, it is disposed an optical input port PI ₁ ~PI ₄ at one end, whereas the optical output port PO ₁ ~PO ₄ on the other end is located, In this embodiment, optical input ports PI ₁ and PI ₂ and optical output ports PO ₃ and PO ₄ are disposed at one end, and optical input ports PI ₃ and PI ₄ and optical are disposed at the other end. Output ports PO ₁ and PO ₂ are arranged.

  In this way, in the optical switch device according to the present embodiment, in addition to the add / drop of the OCS optical signal and the OPS optical signal, the add / drop of the OPS optical signal can be realized on the same chip. Miniaturization is possible. Further, regarding the connection loss with the optical fiber that is the loss source of the optical switch device, it is not necessary to connect the switching elements with the optical fiber, so that a reduction in loss can be expected.

Further, in the optical switch device shown in the second embodiment, the switching elements are connected to each other using the optical waveguides 82 _{1 to} 82 ₆ on the chip substrate 81, so that an intersection is generated in some of the optical waveguides. However, in the optical switch device according to the present embodiment, the intersection of the optical waveguides is eliminated by changing the arrangement of the optical input / output ports and the switching elements. In general, loss of light intensity and crosstalk to other ports occur at the intersections of the optical waveguides. Therefore, in this embodiment, it is possible to suppress deterioration of signal characteristics.

[Example 4]
FIG. 12 shows an optical switch device according to this embodiment. Here, similarly to the optical switch device shown in the first embodiment, the optical switch device has four optical input ports PI _{1 to} PI ₄ and four optical output ports PO _{1 to} PO ₄ , and the OCS optical signal and the OPS light are used. It is assumed that signals can be transferred simultaneously. For add / drop between the OCS optical signal and the OPS optical signal, _two of 1 × ₂ SW 51 ₁ , 51 ₂ and two of 2 × ₁ SW 52 ₁ , 52 ₂ are used, and for add / drop of the OPS optical signal, 2 × Two 2SWs 53 ₁ and 53 ₂ are used. In other words, the optical input ports PI _{1 to} PI ₄ , the optical output ports PO _{1 to} PO ₄ , 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ , 2 × 2 SW 53 ₁ , 53 ₂ are arranged. Except for this, the configuration is the same as that of the optical switch device shown in the first embodiment. Therefore, the same reference numerals are given in FIG.

Also in the optical switch device according to the present embodiment, 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are integrated on one chip as switching elements, and each switching element They are connected by an optical waveguide having a structure equivalent to that of the optical waveguide shown in FIG. Specifically, optical waveguides 85 _{1 to} 85 ₆ are monolithically integrated on the same chip substrate 81 together with ₁ × ₂ SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ , The optical switches are connected by optical waveguides 85 _{1 to} 85 ₆ .

Specifically, 1 one of the optical output port of × 2SW51 ₁ is the optical waveguide 85 ₁ is connected to the 2 × 1SW52 ₁ of one of the optical input port, the 1 × 2SW51 ₁ of the other optical output port, The optical waveguide 85 ₂ is connected to one optical input port of the 2 × 2 SW 53 ₂ . Further, the 1 × 2SW51 one optical output port of the _2, the optical waveguide 85 _3, is connected to the 2 × 1SW52 ₂ of one of the optical input port, 1 × 2SW51 ₂ of the other light output port, the optical waveguide 85 ₄ is connected to the other optical input port of the 2 × 2 SW 53 ₂ . Further, the 2 × 2SW53 ₁ of one of the optical output port, the optical waveguide 85 _5, is connected to the 2 × 1SW52 ₁ of the other optical input port, the 2 × 2SW53 ₁ of the other light output port, the optical waveguide the 85 _6, are connected to the ₂ × 1SW52 2 of the other optical input port.

The 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 1 are arranged so that all of the optical input ports PI _{1 to} PI ₄ and the optical output ports PO _{1 to} PO ₄ are arranged at one end of the chip substrate 81. , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are arranged.

Due to the arrangement described above, the arrangement of the optical input ports PI _{1 to} PI ₄ and the optical output ports PO _{1 to} PO ₄ is different from those of the second and third embodiments. Specifically, in Example 2, is disposed an optical input port PI ₁ ~PI ₄ at one end, an optical output port PO ₁ ~PO ₄ is disposed at the other end, in the third embodiment The optical input ports PI ₁ and PI ₂ and the optical output ports PO ₃ and PO ₄ are disposed at one end, and the optical input ports PI ₃ and PI ₄ and the optical output ports PO ₁ and PO ₂ are disposed at the other end. In contrast, the optical input ports PI _{1 to} PI ₄ and the optical output ports PO _{1 to} PO ₄ are all arranged at one end in the present embodiment.

  In this way, in the optical switch device according to the present embodiment, in addition to the add / drop of the OCS optical signal and the OPS optical signal, the add / drop of the OPS optical signal can be realized on the same chip. Miniaturization is possible. Further, regarding the connection loss with the optical fiber that is the loss source of the optical switch device, it is not necessary to connect the switching elements with the optical fiber, so that a reduction in loss can be expected.

  Further, in the optical switch device according to the present embodiment, the optical input / output port of the optical switch device is aligned on one side of the chip so that it can be easily modularized.

[Example 5]
FIG. 13 shows an optical switch device according to this embodiment. Here, similarly to the optical switch device shown in the first embodiment, the optical switch device has four optical input ports PI _{1 to} PI ₄ and four optical output ports PO _{1 to} PO ₄ , and the OCS optical signal and the OPS light are used. It is assumed that signals can be transferred simultaneously. For add / drop between the OCS optical signal and the OPS optical signal, _two of 1 × ₂ SW 51 ₁ , 51 ₂ and two of 2 × ₁ SW 52 ₁ , 52 ₂ are used, and for add / drop of the OPS optical signal, 2 × Two 2SWs 53 ₁ and 53 ₂ are used. In other words, the optical input ports PI _{1 to} PI ₄ , the optical output ports PO _{1 to} PO ₄ , 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ , 2 × 2 SW 53 ₁ , 53 ₂ are arranged. Except for this, the configuration is the same as that of the optical switch device shown in the first embodiment. Therefore, the same reference numerals are given in FIG.

Also in the optical switch device according to the present embodiment, 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are integrated on one chip as switching elements, and each switching element They are connected by an optical waveguide having a structure equivalent to that of the optical waveguide shown in FIG. Specifically, the optical waveguides 86 _{1 to} 86 ₆ are monolithically integrated on the same chip substrate 81 together with ₁ × ₂ SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ , The optical switches are connected by optical waveguides 86 _{1 to} 86 ₆ .

Specifically, 1 one of the optical output port of × 2SW51 ₁ is the optical waveguide 86 ₁ is connected to the 2 × 1SW52 ₁ of one of the optical input port, the 1 × 2SW51 ₁ of the other optical output port, The optical waveguide 86 ₂ is connected to one optical input port of the 2 × 2 SW 53 ₂ . Also, 1 × 2SW51 ₂ of one of the optical output port, the optical waveguide 86 _3, is connected to the ₂ × 1SW52 2 of one of the optical input port, 1 × 2SW51 ₂ of the other light output port, the optical waveguide 86 ₄ is connected to the other optical input port of the 2 × 2 SW 53 ₂ . Further, the 2 × 2SW53 ₁ of one of the optical output port, the optical waveguide 86 _5, is connected to the 2 × 1SW52 ₁ of the other optical input port, the 2 × 2SW53 ₁ of the other light output port, the optical waveguide the 86 _6, are connected to the ₂ × 1SW52 2 of the other optical input port.

The 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 ₁ , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are connected to each other so that the optical waveguides 84 _{1 to} 84 ₆ connecting them do not cross each other. Are arranged adjacent to each other. The 1 × 2 SW 51 ₁ , 51 ₂ , 2 × ₁ SW 52 1 are arranged so that all of the optical input ports PI _{1 to} PI ₄ and the optical output ports PO _{1 to} PO ₄ are arranged at one end of the chip substrate 81. , 52 ₂ and 2 × 2 SW 53 ₁ , 53 ₂ are arranged.

For example, the end of one side of the chip substrate 81, ₁ × 2SW51 1 and 2 × 2SW53 ₂ which are connected by optical waveguides ₈₆₂ are arranged adjacent, and 2 × 2SW53 ₂ which are connected by the optical waveguide 86 ₄ 1 × 2SW51 ₂ are arranged adjacent, 1 × 2SW51 ₂ and 2 × 1SW52 ₂ are arranged adjacently, ₂ × 1SW52 2 and 2 × connected by optical waveguides 86 ₆ connected by optical waveguides 86 ₃ 2SW53 ₁ are arranged adjacently, 2 × 2SW53 ₁ and 2 × 1SW52 ₁ connected by optical waveguides 86 ₅ are arranged adjacent. The 1 × 2 SW 51 ₁ and the 2 × ₁ SW 52 ₂ connected by the optical waveguide 86 ₁ are arranged at both ends of one end portion of the chip substrate 81, but it can be said that they are arranged adjacent to each other on the connection. .

Due to the arrangement described above, the arrangement of the optical input ports PI _{1 to} PI ₄ and the optical output ports PO _{1 to} PO ₄ is different from those of the second and third embodiments. Specifically, in Example 2, is disposed an optical input port PI ₁ ~PI ₄ at one end, an optical output port PO ₁ ~PO ₄ is disposed at the other end, in the third embodiment The optical input ports PI ₁ and PI ₂ and the optical output ports PO ₃ and PO ₄ are disposed at one end, and the optical input ports PI ₃ and PI ₄ and the optical output ports PO ₁ and PO ₂ are disposed at the other end. In contrast, in this embodiment, the optical input ports PI _{1 to} PI ₄ and the optical output ports PO _{1 to} PO ₄ are all arranged at one end.

  In this way, in the optical switch device according to the present embodiment, in addition to the add / drop of the OCS optical signal and the OPS optical signal, the add / drop of the OPS optical signal can be realized on the same chip. Miniaturization is possible. Further, regarding the connection loss with the optical fiber that is the loss source of the optical switch device, it is not necessary to connect the switching elements with the optical fiber, so that a reduction in loss can be expected.

  Further, in the optical switch device according to the present embodiment, the optical input / output port of the optical switch device is aligned on one side of the chip so that it can be easily modularized.

Further, in the optical switch device shown in the fourth embodiment, since the switching elements are connected to each other using the optical waveguides 85 _{1 to} 85 ₆ on the chip substrate 81, a crossing portion is generated in some of the optical waveguides. However, in the optical switch device according to the present embodiment, the intersections of the optical waveguides are eliminated by changing the arrangement of the optical input / output ports and the switching elements. In general, loss of light intensity and crosstalk to other ports occur at the intersections of the optical waveguides. Therefore, in this embodiment, it is possible to suppress deterioration of signal characteristics.

[Example 6]
In the present embodiment, modified examples of the first to fifth embodiments will be described. In the first to fifth embodiments described above, a form with a small number of optical input / output ports is shown for the sake of simplicity. However, the first to fifth embodiments can be applied to a form with a large number of optical input / output ports. is there. Therefore, the configuration of the optical switch device having a large number of optical input / output ports will be described with reference to FIG. 14, taking the optical switch device shown in FIG. 6 of Embodiment 1 as an example.

  Each of K, L, M, and N is an integer of 1 or more, the optical input / output port of the optical switch for adding / dropping the OCS optical signal and the OPS optical signal is an N port, and the optical switch for adding / dropping the OPS optical signal The input / output port is an M port, the optical input / output port between optical switches for cut-through of OCS optical signals is an L port, and the optical input / output port between optical switches for add / drop of OPS optical signals is K. Port. In this case, as shown in FIG. 14, the optical switch for adding / dropping the OCS optical signal and the OPS optical signal includes N × (K + L) SW 91 and (K + L) × N port configurations having an N × (K + L) port configuration. (K + L) × NSW 92, and the optical switch for adding and dropping the OPS optical signal may be M × KSW 93 having an M × K port configuration and K × MSW 94 having a K × M port configuration.

That is, N × (K + L) SW 91 has optical input ports PI1 _{1 to} PI1 _N , optical output ports PMO1 _{1 to} PMO1 _L, and optical output ports PMO2 _{1 to} PMO2 _K , and (K + L) × NSW 92 is an optical input port. PMI1 _{1 to} PMI1 _L, optical input ports PMI2 _{1 to} PMI2 _K , optical output ports PO1 _{1 to} PO1 _N , M × KSW 93 includes optical input ports PI2 _{1 to} PI2 _M and optical output ports PMO3 _{1 to} PMO3 _K The K × MSW 94 has optical input ports PMI3 _{1 to} PMI3 _K and optical output ports PO2 _{1 to} PO2 _M.

Then, the N × (K + L) SW91 optical output port _{PMO1 1 ~PMO1 L, (K +} L) is connected to the optical input port PMI1 ₁ ~PMI1 _L of × NSW92, N × (K + L) SW91 optical output ports pMO2 ₁ ~ connect pMO2 _K, connected to an optical input port PMI3 ₁ ~PMI3 _K of K × MSW94, an optical output port pMO3 ₁ ~PMO3 _K of M × KSW93, the (K + L) optical input port PMI2 ₁ ~PMI2 _K of × NSW92 doing.

  Each of such N × (K + L) SW 91, (K + L) × NSW 92, M × KSW 93 and K × MSW 94 has at least one 1 × J using the above-described 1 × J distribution selection type optical switch as a basic component. It consists of a distribution selection type optical switch. Alternatively, one 1 × 2 MZI optical switch 30 having the 1 × J MZI optical switch 30 described above or a 1 × J optical switch composed of a plurality of 2 × 2 MZI optical switches 60 as basic components. Alternatively, it is composed of at least one 1 × J optical switch.

  In FIG. 14, the N × (K + L) SW 91 and (K + L) × NSW 92 optical input / output ports for adding and dropping the OCS optical signal and the OPS optical signal are N ports. N optical switches may be used with a single port. However, in such a case, in the N optical switches on the input side, the optical output port for add / drop of the OPS optical signal is set so that the total number of optical output ports for cut-through of the OCS optical signal becomes L port. Similarly, the OPS optical signal must be set so that the total number of optical input ports for cut-through of the OCS optical signal is L ports in the N optical switches on the output side. It is necessary to make the total number of add-drop optical input ports equal to K ports.

This will be described with reference to FIG. 6. In the configuration shown in FIG. 6, N = 2, M = 2, L = 2, K = 2, and two 1 × 2SWs 51 ₁ and 51 ₂ 2 × 1SWs 52 ₁ and 52 ₂ are used. In FIG. 6, the two 1 × 2 SWs 51 ₁ and 51 ₂ on the input side each have one optical output port for cut-through of the OCS optical signal, and the total number L = 2 ports. Each add / drop optical output port is K = 2 ports in total. Similarly, in the two 2 × ₁ SWs 52 ₁ and 52 ₂ on the output side, there is one optical input port for cut-through of the OCS optical signal, and a total number L = 2 ports, for add / drop of the OPS optical signal. The number of optical input ports is one and the total number is K = 2.

  As described above, the optical switch device shown in the first embodiment can be applied to a form having a large number of optical input / output ports. In addition, the configuration of the second embodiment is substantially the same as that of the first embodiment, and the configurations of the optical input / output ports and the switching elements are different from those of the third to fifth embodiments. The configuration is the same as that of the first embodiment. Therefore, the modification described with reference to FIG. 14 is also applicable to the second to fifth embodiments.

  The present invention is suitable for an optical switch device for a node device of a large-capacity optical communication network.

20 Distribution Selection Type Optical Switch 21 1 × 2 Optical Coupler 22 ₁ , 22 ₂ Optical Waveguide 23 ₁ , 23 ₂ Optical Absorption Gate 30 MZI Type Optical Switch 31 1 × 2 Optical Coupler 32 ₁ , 32 ₂ Optical Waveguide 33 ₁ , 33 ₂ Control electrode 34 2 × 2 optical coupler 51 ₁ , 51 ₂ 1 × 2SW
52 ₁ , 52 ₂ 2 × 1SW
53 ₁ , 53 ₂ 2 × 2SW
54 _{1 to} 54 ₆ optical fiber 60 MZI type optical switch 61 2 × 2 optical coupler 62 ₁ , 62 ₂ optical waveguide 63 ₁ , 63 ₂ control electrode 64 2 × 2 optical coupler 70 2 × 2 SW
71 _{1-71 4} broadcast-and-select optical switch 72 _{1-72 4} optical waveguide 81 chip substrate 82 _{1-82 6} optical waveguide 83 ₁ to 83 ₄ EAM
84 _{1-84 6} optical waveguide 85 _{1-85 6} optical waveguide 86 _{1-86 6} optical waveguide 91 N × (K + L) SW
92 (K + L) × NSW
93 M × KSW
94 K x MSW

Claims (10)

In an optical switch device provided in a node device constituting a network and having a plurality of optical input ports and a plurality of optical output ports,
The optical switch device includes a plurality of optical switches,
The optical switch has an optical waveguide structure made of a material whose refractive index or absorption coefficient changes in the order of nanoseconds, and an OCS optical signal which is an optical signal of an optical circuit switching system by changing the refractive index or the absorption coefficient. And an OPS optical signal, which is an optical packet switching type optical signal, is switched. The optical switch device according to claim 1,
The node device is a ROADM (Reconfigurable Optical Add / Drop Multiplexer) node device having a wavelength selective switch,
The optical switch device is
An add / drop process between the OCS optical signal and the OPS optical signal is arranged after the wavelength selective switch and switches the OCS optical signal and the OPS optical signal to the preset optical output port. A first optical switch unit comprising a plurality of the optical switches that perform the switching, and a plurality of the optical switches that perform the add / drop processing of the OPS optical signal by switching the OPS optical signal to the preset optical output port. And a second optical switch unit. The optical switch device according to claim 2,
An optical system comprising: a network controller that controls switching in the first optical switch unit; and a label table that controls switching in the second optical switch unit based on a label of the OPS optical signal. Switch device. In the optical switch device according to claim 2 or 3,
If K, L, M, and N are each an integer of 1 or more,
The first optical switch unit includes an N × (K + L) optical switch having an N × (K + L) port configuration and an (K + L) × N optical switch having a (K + L) × N port configuration,
The second optical switch unit includes an M × K optical switch having an M × K port configuration and a K × M optical switch having a K × M port configuration,
The L ports on the output side of the N × (K + L) optical switch are connected to the L ports on the input side of the (K + L) × N optical switch, and K on the output side of the N × (K + L) optical switch. Connected to the K ports on the input side of the K × M optical switch,
An optical switch device characterized in that K ports on the output side of the M × K optical switch are connected to K ports on the input side of the (K + L) × N optical switch. The optical switch device according to claim 4,
If J is an integer greater than or equal to 2,
The N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, and the K × M optical switch are each a 1 × J distribution selection type optical switch having a 1 × J port configuration. Is composed of at least one 1 × J distribution selection type optical switch,
The 1 × J distribution selection type optical switch comprises a 1 × J optical coupler and J light absorption gates. The optical switch device according to claim 4,
If J is an integer greater than or equal to 2,
The N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, and the K × M optical switch are each a 1 × 2 Mach-Zehnder interferometer or a plurality of 2 × 2 Mach-Zehnder interferometers. A 1 × J optical switch having a 1 × J port configuration consisting of: 1 × 2 Mach-Zehnder interferometer or at least one 1 × J optical switch,
The 1 × J optical switch connects one of two ports on the input side of the subsequent 2 × 2 Mach-Zehnder interferometer to each of the two ports on the output side of the previous 2 × 2 Mach-Zehnder interferometer, An optical switching device characterized in that a plurality of the 2 × 2 Mach-Zehnder interferometers are connected in a tree shape in multiple stages. The optical switch device according to any one of claims 4 to 6,
An optical switch device characterized in that a light absorption gate is provided after the N × (K + L) optical switch. In the optical switch device according to any one of claims 4 to 7,
Between the N × (K + L) optical switch and the (K + L) × N optical switch, between the N × (K + L) optical switch and the K × M optical switch, and between the M × K optical switch and the (K + L) × N optical switches are connected to each other by an optical waveguide, and an optical waveguide having an intersection with another optical waveguide is used in some of the optical waveguides.
The light characterized in that the N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, the K × M optical switch, and the optical waveguide are monolithically integrated on the same chip. Switch device. In the optical switch device according to any one of claims 4 to 7,
Between the N × (K + L) optical switch and the (K + L) × N optical switch, between the N × (K + L) optical switch and the K × M optical switch, and between the M × K optical switch and the The (K + L) × N optical switch is connected to each other by an optical waveguide, and the N × (K + L) optical switch and the (K + L) × N optical switch are arranged so that all the optical waveguides do not cross each other. , Arranging the M × K optical switch and the K × M optical switch,
The light characterized in that the N × (K + L) optical switch, the (K + L) × N optical switch, the M × K optical switch, the K × M optical switch, and the optical waveguide are monolithically integrated on the same chip. Switch device. In the optical switch device according to claim 8 or 9,
An optical switch device characterized in that all of the optical input port and the optical output port of the optical switch device are arranged at one end of the chip.

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