JP2004117449A - Wavelength selection filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wavelength selection filter which can be downsized, is produced with high mass productivity and has high reliability. <P>SOLUTION: The wavelength selection filter has an optical switch 3 with a plurality of input waveguides and a plurality of output waveguides, and an array waveguide type diffraction grating circuit 2 with an input waveguide part 7, an output waveguide part 8, light diffracting input and output side slab waveguide parts 6a, 6b and a plurality of array waveguide parts 5 held between the input and output side slab waveguide parts 6a, 6b, with an optical path difference. The wavelength selection filter in which the optical switch 3 and the array waveguide type diffraction grating circuit 2 form a plane light-wave circuit constructed with optical waveguides consisting of high refractive index cores and surrounding claddings formed on a silicon substrate 1 and the output waveguides of the optical switch 3 are individually connected to the input waveguide part 7 of the array waveguide type diffraction grating circuit 2 is provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wavelength selective filter for a wavelength division multiplexing (WDM) system.
[0002]
[Prior art]
With the explosive spread of the Internet, the capacity of communication lines has been rapidly increasing, mainly in the United States. As a key technology for increasing the capacity, a wavelength division multiplexing (WDM) system has been widely used.
[0003]
In order to construct a photonic network in which electrical processing is reduced as much as possible based on WDM, a wavelength selection filter is required. This is because it is effective as an element for switching wavelengths when path setting is performed in wavelength units. Further, by combining with a multi-wavelength light source, it is possible to configure a wavelength variable light source.
[0004]
FIG. 7 is a configuration diagram showing a conventional wavelength selection filter.
[0005]
Conventional wavelength selection filters are usually configured by combining bulk optical components such as lenses and gratings. Specifically, as shown in FIG. ₁ ~ Λ _n Input fiber 51, a collimating lens 52 disposed in front of the input fiber 51 in the traveling direction of the signal light and condensing the signal light, a bulk grating 53 further disposed in front of the collimating lens 52, and a bulk grating It is composed of a collimating lens 54 for condensing the signal light demultiplexed by 53, and an output fiber 55 for outputting the signal light condensed by the collimating lens 54.
[0006]
In the wavelength selection filter, the WDM signal λ ₁ ~ Λ _n Is condensed by the collimating lens 52 and is split by the bulk grating 53. The signal light split by the bulk grating 53 changes its diffraction direction depending on the wavelength (see Non-Patent Document 1). Therefore, by rotating the angle of the bulk grating 53, the wavelength λ of the signal light entering the output fiber 55 _i And can be operated as a wavelength selection filter.
[0007]
[Non-patent document 1]
S. V. Kartalopoulos, Introduction to DWDM Technology, p. 88-89
[0008]
[Problems to be solved by the invention]
However, the conventional wavelength selection filter shown in FIG. 7 has a drawback that it is difficult to reduce the size and has low mass productivity because it is configured by combining bulk optical components.
[0009]
Further, since wavelength selection (variable) is performed by mechanical operation, there is a disadvantage that there is a movable part and reliability is not good. Therefore, a small, low-cost, and highly reliable wavelength selection filter has not been realized until now.
[0010]
With the increase in the number of channels in a WDM system for increasing the capacity, a small-sized, low-cost, and highly reliable multi-channel wavelength selective filter is desired. In particular, in order to reduce the installation area of the system, a wavelength selection filter that can be integrated on a board (substrate) is required.
[0011]
The present invention has been made in view of the above problems, and has as its object to provide a wavelength selection filter that can be reduced in size, has high mass productivity, and has high reliability.
[0012]
[Means for Solving the Problems]
A wavelength selection filter according to claim 1 of the present invention that solves the above-mentioned problems includes an optical switch having a plurality of input waveguides, a plurality of output waveguides, a plurality of other input waveguides, and a plurality of other input waveguides. An output waveguide, an input-side slab waveguide and an output-side slab waveguide that diffract light, and a plurality of arrayed waveguides having different optical path length differences sandwiched between the input-side slab waveguide and the output-side slab waveguide. Having an arrayed waveguide type diffraction grating circuit having the optical switch and the arrayed waveguide type diffraction grating circuit, wherein the optical switch and the arrayed waveguide type diffraction grating circuit are formed of an optical waveguide including a core having a high refractive index formed on a planar substrate and a clad around the core. Wherein the output waveguide of the optical switch is connected to the other input waveguide of the arrayed waveguide grating circuit or the other output of the arrayed waveguide grating circuit. The waveguide is The input waveguide of the switch, respectively, characterized in that connected individually.
[0013]
According to another aspect of the present invention, there is provided a wavelength selection filter including a plurality of the arrayed waveguide type diffraction grating circuits, wherein the arrayed waveguide type diffraction grating circuits are connected in multiple stages. .
[0014]
According to a third aspect of the present invention, there is provided a wavelength selection filter according to the third aspect, wherein the optical switch is a thermo-optical switch, and the arrayed waveguide type diffraction grating circuit and the thermo-optical switch are separately manufactured, and each of them is connected to each other. It is characterized by being directly connected at the end face of the wave path.
[0015]
According to a fourth aspect of the present invention, there is provided a wavelength selective filter, wherein at least one of the optical switch and the arrayed waveguide type diffraction grating circuit is made of a silica-based optical waveguide, and the optical switch and the arrayed waveguide type diffraction grating circuit are formed at the end faces of the waveguides. It is characterized by being directly connected.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram illustrating a basic configuration example of an embodiment of the present invention.
[0017]
As shown in FIG. 1, a wavelength selection filter according to the present invention includes a Si substrate 1 which is a planar substrate, an arrayed waveguide grating multiplexer / demultiplexer (hereinafter, AWG) 2 provided on the Si substrate, and An M × N optical switch 3 provided on the substrate 1 and having M inputs as a plurality of input waveguides and N outputs (M and N are positive integers) as a plurality of output waveguides is provided. are doing. FIG. 1 illustrates a 1 × 8 optical switch as an example of the M × N optical switch 3.
[0018]
The M × N optical switch 3 is configured by connecting a plurality of optical switches in multiple stages. FIG. 1 illustrates an MZI (Mach-Zehnder interferometer) type thermo-optic switch (hereinafter, TOSW) 3a as an optical switch. One TOSW 3a has two 3-dB directional couplers, two arm waveguides of substantially equal length sandwiched therebetween, and a thin-film heater 4 formed on one of the arm waveguides. ing. By heating the heater 4, the phase of the signal light of one of the arm waveguides is controlled to perform a switching operation.
[0019]
The AWG 2 includes an arrayed waveguide section 5 including a plurality of optical waveguides having different lengths (optical path lengths), an input side slab waveguide section 6a arranged to sandwich the arrayed waveguide section 5, and an output side slab waveguide section. 6b, an input waveguide section 7 connected to the slab waveguide sections 6a and 6b, and an output waveguide section 8 having a plurality of optical waveguides. Note that, depending on the configuration of the wavelength selection filter, the number of the waveguides of the output waveguide unit 8 may not be plural.
[0020]
The waveguide on the output side of the M × N optical switch 3 is connected to the individual waveguides of the input waveguide unit 7 of the AWG 2, respectively, so that the M × N optical switch 3 and the AWG 2 are combined with each other to select a wavelength. It will function as a filter. Note that the connection direction does not necessarily need to be connected from the M × N optical switch 3 to the AWG 2, but may be connected from the AWG 2 to the M × N optical switch 3, as a wavelength selection filter having the same function. Operate.
[0021]
A planar lightwave circuit (hereinafter, PLC) is formed by depositing a high-refractive-index core such as quartz and a clad around it on a planar substrate such as silicon (Si) or quartz and integrating them as an optical waveguide circuit. . An arrayed waveguide grating multiplexer / demultiplexer (AWG) is a type of PLC, and an optical switch can also be formed by PLC. Therefore, both can be integrated and manufactured on the same substrate, and connection with each other is easy. Become. In addition, since the PLC can use the microfabrication technology of LSI manufacturing, a highly accurate and highly reliable PLC can be formed. Note that the arrayed waveguide grating multiplexer / demultiplexer (AWG) and the optical switch are not formed on the same substrate but are separately manufactured, and the end faces of the respective waveguides are directly joined to connect the respective optical waveguides. You may. In the case where an arrayed waveguide grating multiplexer / demultiplexer (AWG) and an optical switch are individually manufactured, it is not always necessary that both are constituted by a silica-based optical waveguide, and at least one is constituted by a quartz-based optical waveguide. The other side may be made of, for example, a polymer optical waveguide. By individually manufacturing the arrayed waveguide grating multiplexer / demultiplexer (AWG) and the optical switch, the yield of each of the arrayed waveguide type diffraction grating circuit and the thermo-optic switch having different fabrication processes can be improved, and further, By freely combining an arrayed waveguide type diffraction grating circuit and a thermo-optic switch that are individually manufactured, the degree of freedom in design can be increased, and a flexible configuration according to the network can be achieved.
[0022]
Next, the operation of the waveguide type wavelength selection filter shown in FIG. 1 will be described. The wavelength λ is applied to the input side of the M × N optical switch 3. ₁ ~ Λ _n Is input. The output of the M × N optical switch 3 is switched and introduced to a specific port (optical waveguide) of the AWG 2. The wavelength selected at the output port depends on the port of AWG2. Thus, by switching the output port of the M × N optical switch 3, the wavelength can be selected.
[0023]
The wavelength selection filter having the above structure according to the present invention is a planar lightwave filter fabricated on a flat substrate such as a Si substrate in order to overcome the drawbacks of the conventional wavelength selection filter such as difficulty in downsizing and low mass productivity. A wavelength selection filter was configured using a circuit (PLC). By using the PLC, a highly reliable wavelength selection filter having no moving parts can be formed, and downsizing, integration, and mass production, which are characteristics of the PLC, can be achieved. That is, in the present invention, an optical switch and an AWG are formed by a PLC, and the optical switch and the AWG are combined and integrated to constitute a wavelength selection filter, thereby providing a small, low-cost, and highly reliable wavelength selection filter. It has been realized.
[0024]
Further, by using the PLC, the AWG and the optical switch can be manufactured by the same process, the mass productivity can be further improved, and the large-scale channel can be easily formed. Furthermore, LN (LiNbO) is used as an optical switch. ₃ Using a (waveguide) type optical switch also enables high-speed switching.
[0025]
Hereinafter, specific examples of the embodiment of the present invention will be described in detail with reference to the drawings (FIGS. 2 to 6).
[0026]
(Example 1)
FIG. 2 shows an example of an embodiment of the present invention, and is a configuration diagram of an eight-channel wavelength selection filter.
[0027]
The eight-channel wavelength selection filter of the present embodiment is formed of a quartz PLC formed on a Si substrate, and is formed by directly joining the optical switches and the AWGs which are individually formed. Produced.
[0028]
As shown in FIG. 2, the wavelength selection filter of the present embodiment is formed on a Si substrate, and an athermal type AWG 12 of eight channels composed of a silica-based glass waveguide. It has a 1 × 8 (one input and eight outputs) optical switch 13 composed of a glass waveguide. The size of the core of the silica-based waveguide was 6 × 6 μm, the relative refractive index difference between the core and the clad was 0.75%, and the thickness of the Si substrate 1 was 1.0 mm.
[0029]
The 1 × 8 optical switch 13 has a configuration in which a plurality of MZI (Mach-Zehnder interferometer) type thermo-optical switches (hereinafter, TOSW) 13a are connected in a multi-tiered tree shape, and has a chip size of 10 × 40 mm. One TOSW 13a has two 3-dB directional couplers, two arm waveguides of substantially equal length sandwiched therebetween, and a thin-film heater 14 formed on one of the arm waveguides. ing. The PLC chip of the 1 × 8 optical switch 13 was mounted on a package with electrodes, and electrical wiring on the PLC was connected to electrode pads of the package by wire bonding.
[0030]
The athermal type AWG 12 includes an array waveguide section 15 including a plurality of optical waveguides having different lengths (optical path lengths), an input side slab waveguide section 16 a arranged so as to sandwich the array waveguide section 15, and an output side slab waveguide. It has a waveguide section 16b, and an input waveguide section 17 and an output waveguide section 18 connected to the respective slab waveguide sections 16a and 16b. The array waveguide section 15 is provided with an insertion groove into which the athermalizing polymer 19 is inserted, and the athermalizing polymer 19 is inserted to make it an athermal type. By using the athermal polymer 19, the influence of thermal crosstalk can be avoided. As the athermal polymer, for example, a silicone resin is used. The athermal AWG 12 had a size of 25 × 30 mm and a wavelength interval of 100 GHz.
[0031]
The wavelength selection filter was configured by connecting the 1 × 8 optical switch 13 and the athermal type AWG 12 to each other at the end faces (PLC end faces) of the respective waveguides. The output fiber of the 1 × 8 optical switch 13 was connected to the input waveguide 17 one core at a time.
[0032]
FIG. 3 is a graph showing the optical characteristics of the wavelength selection filter having the above configuration evaluated by driving the 1 × 8 optical switch 13. The spectrum was measured using an ASE (Amplified Spontaneous Emission) light source of an EDFA (Erbium Doped Fiber Amplifier) and a spectrum analyzer. In FIG. 3, the spectrum measured in each channel is shown in one graph.
[0033]
As is clear from FIG. 3, good spectra were obtained for each channel, low loss and low crosstalk were realized, and the effectiveness of the present invention was confirmed.
[0034]
(Example 2)
FIG. 4 shows another example of the embodiment of the present invention, and is a configuration diagram of a 32-channel wavelength selection filter.
[0035]
The 32-channel wavelength selection filter of this embodiment is one in which an optical switch and an AWG are both formed on a single Si substrate by PLC. In this embodiment, the AWG has a revolving 32 channel output port.
[0036]
As shown in FIG. 4, the wavelength selection filter of the present embodiment is formed on a Si substrate and has a 32-channel orbiting AWG 22 formed of a silica-based glass waveguide. It has a 1 × 32 (one input and 32 outputs) optical switch 23 composed of a glass waveguide. These are fabricated on one substrate, the size of the core of the quartz-based waveguide is 4.5 × 4.5 μm, the relative refractive index difference between the core and the clad is 1.5%, and the thickness of the Si substrate is The length was 1.0 mm.
[0037]
The 1 × 32 optical switch 23 has a configuration in which a plurality of MZI (Mach-Zehnder interferometer) -type thermo-optical switches (hereinafter, “TOSW”) 23 a are connected in multiple stages in a tree shape. One TOSW 23a is composed of two 3 dB directional couplers, two arm waveguides interposed therebetween and having substantially the same length, and a thin film heater 24 for driving a switch formed on one arm waveguide. And In FIG. 4, the 1 × 32 optical switch 23 is illustrated in a simplified manner. However, actually, a 32-channel waveguide is connected between the 1 × 32 optical switch 23 and the orbiting AWG 22.
[0038]
The orbiting AWG 22 includes an arrayed waveguide section 25 composed of a plurality of optical waveguides having different lengths (optical path lengths), an input slab waveguide section 26a arranged so as to sandwich the arrayed waveguide section 25, and an output slab waveguide section. It has a waveguide section 26b, and an input waveguide section 27 and an output waveguide section 28 connected to the respective slab waveguide sections 26a and 26b. In the circular AWG 22 having 32 channels, the wavelength of the output port sequentially and periodically changes depending on the input port. That is, by changing the input port, the output port can be changed depending on the wavelength. Therefore, when the port input to the recirculating AWG 22 is changed by the 1 × 32 optical switch 23, the output of 32 wavelengths is separated, and the position of the output port is sequentially changed. The substrate size of the wavelength selection filter was 70 × 30 mm, and the wavelength interval was 100 GHz.
[0039]
One input fiber and 32 output fibers were connected to the wavelength selection filter. The PLC chip was mounted on a package with electrodes, and electric wiring on the PLC was connected to electrode pads of the package by wire bonding.
[0040]
The optical characteristics of the wavelength selection filter having the above configuration were evaluated using a high-band light source and a spectrum analyzer. By driving the 1 × 32 optical switch 23 to change the input port, it was confirmed that each output port sequentially moved. In addition, low loss and low crosstalk were realized in each channel, and the effectiveness of the present invention was confirmed.
[0041]
(Example 3)
FIG. 5 shows another example of the embodiment of the present invention, and is a configuration of a wavelength selection filter of 64 channels.
[0042]
In this example, a 64-channel wavelength selective filter composed of PLC was fabricated on a Si substrate. Further, the wavelength selection filter of 64 channels has a plurality of AWGs in order to reduce crosstalk, and has a configuration in which the AWGs are connected in multiple stages. In the present embodiment, a two-stage configuration is used as an example.
[0043]
As shown in FIG. 5, the wavelength selection filter of the present embodiment is formed on a Si substrate and has a 64-channel AWG 32 formed of a silica glass waveguide, and also formed on a Si substrate, and has a quartz glass conductor. It has a 1 × 64 (one input and 64 outputs) optical switch 33 constituted by a wave path, and further has 64 1 × 1 bandpass AWGs 39. Sixty-four 1 × 1 bandpass AWGs 39 and 64 channel AWGs 32 are fabricated on one substrate, and the 1 × 64 optical switch 33 is connected to each other at PLC end faces. The size of the core of the silica-based waveguide was 4.5 × 4.5 μm, the relative refractive index difference between the core and the clad was 1.5%, and the thickness of the Si substrate was 1.0 mm. The substrate size of the wavelength selection filter was 70 × 30 mm, and the wavelength interval was 100 GHz.
[0044]
The 1 × 64 optical switch 33 has a configuration in which a plurality of MZI (Mach-Zehnder interferometer) type thermo-optic switches (hereinafter, TOSW) 33a are connected in a multi-tiered tree shape. One TOSW 33a includes two 3-dB directional couplers, two arm waveguides sandwiched between the two waveguides, and a thin-film heater 34 for driving a switch formed on one of the arm waveguides. And In FIG. 5, the 1 × 64 optical switch 33 is illustrated in a simplified manner, but actually, a waveguide of 64 channels is connected between the 1 × 64 optical switch 33 and the AWG 32.
[0045]
The AWG 32 includes an arrayed waveguide section 35 including a plurality of optical waveguides having different lengths (optical path lengths), an input-side slab waveguide section 36a disposed so as to sandwich the arrayed waveguide section 35, and an output-side slab waveguide section. 36b, and an input waveguide 37 and an output waveguide 38 connected to the respective slab waveguides 36a and 36b. The AWG 32 has a band pass AWG 39 added to each input port for the purpose of reducing crosstalk. As a result, it is possible to realize crosstalk with improved characteristics twice as compared with the related art. Therefore, even if the number of channels is increased, good crosstalk characteristics can be maintained, and a device having no practical problem can be manufactured.
[0046]
One input fiber and one output fiber were connected to the wavelength selection filter. The PLC chip was mounted on a package with electrodes, and electric wiring on the PLC was connected to electrode pads of the package by wire bonding.
[0047]
The optical characteristics of the wavelength selection filter having the above configuration were evaluated using a high-band light source and a spectrum analyzer. The input port was changed by driving the 1 × 64 optical switch 33, and very good crosstalk of 80 dB or less was confirmed at each output port. In addition, low loss was realized in each channel, and the effectiveness of the present invention was confirmed.
[0048]
(Example 4)
FIG. 6 shows another example of the embodiment of the present invention, which is a configuration of a four-channel wavelength selection filter.
[0049]
The four-channel wavelength selection filter of this embodiment is composed of individually formed PLC type AWG and LiNbO. ₃ This is constituted by a waveguide (LN) type optical switch. In the wavelength selection filter of this embodiment, the wavelength selection can be switched at high speed by using the LN type optical switch.
[0050]
As shown in FIG. 6, the wavelength selection filter of the present embodiment is formed on a Si substrate, and is formed on a 4-channel athermal type AWG 42 composed of a silica-based glass waveguide. It has a 1 × 4 (one input and four outputs) optical switch 43 composed of a waveguide.
[0051]
The 1 × 4 optical switch 43 has a configuration in which a plurality of MZI (Mach-Zehnder interferometer) type LN optical switches 43a are connected in a multi-tiered tree shape. One LN-type optical switch 43a is composed of two 3 dB directional couplers, two arm waveguides sandwiched therebetween having substantially the same length, and a switch driving switch formed on one of the arm waveguides. And an electrode 44. The electrode gives an electro-optic effect to the optical waveguide, thereby causing a modulation of the refractive index to change the phase. This LN type 1 × 4 optical switch 43 is characterized in that the speed can be increased.
[0052]
The athermal type AWG 42 includes an array waveguide section 45 composed of a plurality of optical waveguides having different lengths (optical path lengths), an input side slab waveguide section 46a disposed so as to sandwich the array waveguide section 45, and an output side slab waveguide. It has a waveguide section 46b and an input waveguide section 47 and an output waveguide section 48 connected to the respective slab waveguide sections 46a and 46b. The array waveguide section 45 is provided with an insertion groove into which the athermalizing polymer 49 is inserted, and the athermal type polymer 49 is inserted to make the array waveguide section 45 an athermal type. By using the athermal polymer 19, the influence of thermal crosstalk can be avoided. As the athermal polymer, for example, a silicone resin is used.
[0053]
The LN-type 1 × 4 optical switch 43 and the athermal-type AWG 42 were connected to each other at their end faces by a UV curing adhesive. The size of the LN type quartz waveguide was 3 × 15 mm, and the substrate thickness was 0.25 mm. The size of the AWG was 10 × 20 mm, and the thickness of the Si substrate was 1.0 mm. The entire size of the wavelength selection filter was as small as 10 × 35 mm, and the wavelength interval was 100 GHz.
[0054]
One input fiber and one output fiber were connected to the wavelength selection filter. A chip in which the LN type 1 × 4 optical switch 43 and the athermal type AWG 42 were connected was mounted on a package with electrodes, and electric wiring on the chip and electrode pads of the package were connected by wire bonding.
[0055]
The optical characteristics of the wavelength selection filter having the above configuration were evaluated using a WDM light source having a high-bandwidth light source of 4 ch and a high-speed detector. The 1 × 4 optical switch 43 was driven at high speed to change the input port, and extremely high-speed switching of about 1 ns was confirmed at each output port, confirming the effectiveness of the present invention.
[0056]
【The invention's effect】
According to the invention according to claim 1, the wavelength selection filter includes an optical switch having a plurality of input waveguides, a plurality of output waveguides, a plurality of other input waveguides, and a plurality of other output waveguides. An array having an input slab waveguide and an output slab waveguide for diffracting light, and a plurality of array waveguides sandwiched between the input slab waveguide and the output slab waveguide and having different optical path length differences. A waveguide type diffraction grating circuit, wherein the optical switch and the arrayed waveguide type diffraction grating circuit are configured by an optical waveguide including a core having a high refractive index formed on a flat substrate and a clad around the core. A planar lightwave circuit, wherein the output waveguide of the optical switch is the other input waveguide of the arrayed waveguide grating circuit, or the other output waveguide of the arrayed waveguide grating circuit is Of the optical switch The Chikarashirube waveguides, since each individually connected to the movable portion and the waste can be reduced in size and high wavelength selective filter reliability at low cost. In addition, if a planar lightwave circuit (PLC) is used, the arrayed waveguide type diffraction grating circuit and the optical switch can be manufactured by the same process, and mass productivity can be further improved. In particular, the thermo-optic switch (TOSW) has been realized up to 128 channels, and it is easy to make it small and large-scale. Furthermore, as an optical switch, LN (LiNbO ₃ If a (waveguide) type optical switch is used, high-speed switching becomes possible.
[0057]
According to the second aspect of the present invention, a plurality of the arrayed waveguide type diffraction grating circuits are provided, and the arrayed waveguide type diffraction grating circuit is connected in multiple stages, thereby realizing a small-sized and large-scale channel wavelength selection filter. As well as low crosstalk.
[0058]
According to the invention according to claim 3, the optical switch is a thermo-optical switch, the arrayed waveguide type diffraction grating circuit and the thermo-optical switch are separately manufactured, and the optical waveguides are directly connected at the end face of the waveguide. Therefore, the yield can be improved by separately manufacturing the arrayed waveguide type diffraction grating circuit and the thermo-optic switch having different manufacturing processes, and furthermore, the individually manufactured arrayed waveguide type diffraction grating circuit By freely combining with the thermo-optic switch, the degree of freedom in design can be increased, and a flexible configuration according to the network can be obtained.
[0059]
According to the invention according to claim 4, at least one of the optical switch and the arrayed waveguide type diffraction grating circuit is made of a silica-based optical waveguide, and the optical waveguides are directly connected to each other at an end face of the waveguide. By freely combining the individually fabricated arrayed waveguide type diffraction grating circuit and the thermo-optic switch, the degree of design freedom can be increased, and a flexible configuration according to the network can be achieved.
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram of a wavelength selection filter according to the present invention.
FIG. 2 is a configuration diagram of an eight-channel wavelength selection filter showing an example of an embodiment of the present invention.
FIG. 3 is a graph showing a spectrum of a wavelength selection filter showing an example of an embodiment of the present invention.
FIG. 4 is a configuration diagram of a 32-channel wavelength selection filter showing another example of the embodiment of the present invention.
FIG. 5 is a configuration diagram of a 64-channel wavelength selection filter showing another example of the embodiment of the present invention.
FIG. 6 is a configuration diagram of a four-channel wavelength selection filter showing another example of the embodiment of the present invention.
FIG. 7 is a structural diagram of a conventional wavelength selection filter.
[Explanation of symbols]
1 Si substrate
2 AWG
3 M × N optical switch
3a Thermo-optical switch (TOSW)
4 heater
5 Array waveguide
6a Slab waveguide on input side
6b Output side slab waveguide
7 Input waveguide
8 Output waveguide
12 Athermal AWG
13 1 × 8 optical switch
13a Thermo-optic switch (TOSW)
14 heater
15 Array waveguide
16a Input side slab waveguide
16b Output side slab waveguide
17 Input waveguide
18 Output waveguide
19 Polymer for athermalization
22 Orbiting AWG
23 1x32 optical switch
23a Thermo-optic switch (TOSW)
24 heater
25 Array Waveguide
26a Input side slab waveguide
26b Slab waveguide on output side
27 Input waveguide
28 Output waveguide
32 AWG
331 1x64 optical switch
33a Thermo-optic switch (TOSW)
34 heater
35 Array Waveguide
36a Input side slab waveguide
36b Output side slab waveguide
37 Input waveguide
38 Output waveguide
39 Band Pass AWG
42 Athermal AWG
43 1 × 4 Optical Switch
43a LN type optical switch
44 electrodes
45 Array waveguide
46 Slab waveguide
46a Input side slab waveguide
46b Output side slab waveguide
47 Input waveguide
48 Output waveguide
49 Polymer for athermalization

Claims (4)

An optical switch having a plurality of input waveguides and a plurality of output waveguides,
A plurality of other input waveguides, a plurality of other output waveguides, an input slab waveguide and an output slab waveguide that diffract light, and are sandwiched between the input slab waveguide and the output slab waveguide. Having an arrayed waveguide type diffraction grating circuit having a plurality of arrayed waveguides having different optical path length differences,
The optical switch and the arrayed waveguide type diffraction grating circuit is a planar lightwave circuit composed of an optical waveguide composed of a high refractive index core formed on a planar substrate and a clad around the core,
The output waveguide of the optical switch is connected to the other input waveguide of the arrayed waveguide grating circuit, or the other output waveguide of the arrayed waveguide grating circuit is connected to the input waveguide of the optical switch. Wavelength selective filters each individually connected to a wave path. The wavelength selection filter according to claim 1,
A wavelength selection filter comprising a plurality of the arrayed waveguide type diffraction grating circuits, wherein the arrayed waveguide type diffraction grating circuits are connected in multiple stages. The wavelength selection filter according to claim 1 or 2,
A wavelength selection filter, wherein the optical switch is a thermo-optic switch, and the arrayed waveguide type diffraction grating circuit and the thermo-optic switch are separately manufactured, and are directly connected at end faces of the respective waveguides. The wavelength selection filter according to any one of claims 1 to 3,
A wavelength selective filter, wherein at least one of the optical switch and the arrayed waveguide type diffraction grating circuit is made of a silica-based optical waveguide, and is directly connected at an end face of each waveguide.

Images