JPH10333105A - Wavelength variable filter with polymer optical waveguide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small-sized wavelength variable filter having a sufficiently broad wavelength selection range, capable of varying branching and joining channels, having a simple structure and ensuring low power consumption work. SOLUTION: This wavelength variable filter comprises a wavelength filter with polymer optical waveguides having a grating structure, an input-output optical circuit and a temp. regulator. Optical signals of specified wavelengths are separated and mixed by varying the set temp. of the temp. regulator. The embedded polymer optical waveguides 33 are formed on a metallic substrate with two deuterated and fluorinated polymethacrylates different from each other in refractive index by a prescribed value and different from each other in copolymn. ratio as a cladding material and a core material. The waveguide pattern has a directional coupler 32 having a prescribed coupling ratio connected to the linear waveguides. A refractive index alteration type grating 31 is written in a linear waveguide part with an electron beam lithography system to obtain the wavelength filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an add / drop multiplexer for adding an arbitrary wavelength signal to a wavelength multiplexed optical signal or extracting an arbitrary wavelength signal from the wavelength multiplexed optical signal in a wavelength multiplexed optical communication (WDM) system. The present invention relates to a polymer optical waveguide tunable filter having an (ADM) function.

[0002]

2. Description of the Related Art A WDM system is an optical communication system in which a plurality of optical signals having different wavelengths are multiplexed in a wavelength band that can be transmitted through an optical transmission line, thereby increasing a transmission capacity. In this system, an optical circuit, that is, an ADM that separates (demultiplexes) a signal (channel) of a specific wavelength from a wavelength multiplexed signal or multiplexes (combines) a specific channel is required. The function of the ADM is wavelength filtering, and the signals of the target channel and the remaining channels can be output to different ports. A wavelength filter for this purpose is required to have narrow-band wavelength selectivity in order to sufficiently reduce crosstalk from an adjacent channel. For example, in a WDM system with a wavelength band of 1.55 μm, 16 channels multiplexed at a frequency interval of 100 GHz within a transmission wavelength band of 1.543 to 1.556 μm,
A 2000 GHz 8-channel multiplex system has been actively studied. These have a wavelength interval of 0.8 n each.
m, which is 1.6 nm, and the wavelength filter needs to have a transmission band sufficiently narrower than this interval.

As candidates for such a narrow-band wavelength filter, an arrayed waveguide grating (AWG) filter, a fiber grating (FG) filter, and a dielectric multilayer filter using a quartz plate lightwave circuit (PLC) have been studied. The AWG performs wavelength separation by multiplex interference of light from an array waveguide having an optical path length difference, and has a feature that a plurality of channels can be simultaneously demultiplexed and multiplexed.
The FG filter is formed by forming a refractive index modulation type grating by irradiating ultraviolet light in an optical fiber, and a target channel signal is reflected by the grating and separated in combination with an optical coupler or an optical circulator provided outside. The dielectric multilayer filter is a film-like filter deposited on a substrate, and is used by being embedded so as to traverse the core of the optical waveguide or installed in a parallel optical path using a lens.

[0004] In order to increase the degree of freedom in WDM system design, it is necessary to use an ADM that can change the channels to be combined. In the PLC-AWG, selection of a variable channel is realized by inserting an optical switch for each separated channel. However, this configuration requires optical switches of the same number as the number of channels, and has a disadvantage that the optical circuit becomes large-scale. Further, when a thermo-optic (TO) switch of a PLC is used as an optical switch, there is an advantage that it can be manufactured relatively small on the same substrate as the AWG. However, a large-scale PL with a chip size of about 9 cm × 7 cm is still used.
C. (K. Okamoto et al., Electr
onics Letters, Vol. 32, pp. 1471-1472), and there is also a problem that the power consumption of the TO switch is large. On the other hand, in an ADM using an FG filter, the center wavelength can be changed by giving a refractive index change due to stress or temperature change to the grating portion, but the variable wavelength range is at most 2 nm, which is used for channel selection. A sufficient wavelength tunable range has not been obtained. In order to realize a variable wavelength with a dielectric multilayer filter, mechanical operations such as rotating the filter are required, and miniaturization and high-speed response are difficult.

[0005]

In order to realize a practical ADM, a wavelength filter having a sufficient wavelength selection range and a variable channel for multiplexing and demultiplexing is used. You need something to do. An object of the present invention is to provide a variable channel ADM satisfying these conditions.
(Wavelength tunable filter).

[0006]

The present invention realizes a variable channel ADM that satisfies the above-mentioned conditions by utilizing a large TO constant of a polymer material.

An optical waveguide made of a polymer material has a simpler manufacturing process than a light waveguide made of an inorganic glass material typified by quartz, and is easily provided with functionality such as low temperature and optical nonlinearity. It has been noted and studied. Further, since the thermo-optic (TO) constant of the polymer material is about one order of magnitude larger than that of the inorganic glass, the T
It is also noted that the O-switch operates with small temperature changes, that is, with small heating power.

However, in an optical circuit such as a wavelength filter where the absolute value of the refractive index of the optical waveguide directly determines the characteristics, a large T
The O constant is generally considered to be a drawback because its characteristics become unstable with respect to a change in environmental temperature. On the other hand, in the present invention, the fact that the center wavelength of a wavelength filter using a polymer optical waveguide having a large TO constant greatly changes due to a temperature change is used. SUMMARY OF THE INVENTION The present invention provides a WD by providing a small wavelength filter using a polymer optical waveguide grating with a temperature control device for enabling wavelength selection.
This realizes a wavelength tunable filter having a variable range large enough for channel selection of the M system.

In order to select all the channels of the WDM system, the variable wavelength range of the filter is about 13 nm, that is, about 0.8 nm of the used wavelength (1550 nm).
%is required. No matter which wavelength filter circuit is used, a temperature change of about 1000 ° C. is necessary to realize this wavelength range with the TO effect of the quartz material, which is impossible. On the other hand, in the polymer optical waveguide of the present invention, since the TO constant of the polymer material was large, a sufficient wavelength change could be obtained at about 60 ° C.

In an ADM using a combination of a quartz PLC AWG and a TO switch, both power consumption of constant temperature control for obtaining required wavelength stability and operating power of the TO switch are required. The polymer optical waveguide wavelength filter of the present invention has the same power consumption required for temperature control for tunable wavelength, but does not consume any other power. Even when a thin film heater is used as a temperature controller for tunable wavelength, its power consumption is about 100 mW, as will be described later, which is far less than the operating power (1 W or more) of a quartz PCL TO switch.

In the case where a thin film heater is used as a temperature controller for changing the wavelength in the present invention, it is possible to select a channel at high speed. The heating power and response speed required for the thin-film heater can be obtained by thermal diffusion numerical simulation. Thermal power ratio of general polymer material (0.2 Wm ^-1
K ^-1 ), specific heat (2 × 10 ⁶ JK ^-1 m ^-3 ), TO constant (1
× 10 ^-4 ° C ^-1 ), and the calculation was performed assuming that the area of the wavelength filter portion requiring heating was 30 µm x 3 mm. The heater power for providing a temperature change of 60 ° C. for obtaining a sufficient wavelength range is 110 mW, and the temperature change is 90 mW.
% Was 10 ms.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A polymer optical waveguide wavelength variable filter according to the present invention comprises a polymer optical waveguide grating, an input / output optical circuit, and a temperature controller.

As a polymer optical waveguide grating,
Both relief and refractive index modulation types can be used.

FIGS. 1A and 1B are a perspective plan view and a sectional view taken along the longitudinal direction of the core of the structure of the relief type optical waveguide grating. In the figure, reference numeral 11 denotes a relief grating, 12 denotes a core, 13 denotes a clad, 1
Reference numeral 4 denotes a substrate. The fabrication method conforms to the process of fabricating a normal buried channel waveguide by core ridge processing by thin film deposition by spin coating, photolithography, etching, or the like. The relief type grating 11 is manufactured by applying a resist after depositing the core 12 or forming the core ridge, writing a grating pattern by two-beam interference exposure or phase mask exposure or electron beam drawing, and developing and etching. it can. When a photopolymer is used as the material of the core 12, the core layer can be directly written without using a resist. As the polymer material, any material can be used as long as it can produce a thin film and is stable in a controlled temperature range. Furthermore, in the present invention, a deuterated or deuterated fluorinated acrylic polymer, a silicone resin, or a UV curable resin as the optical waveguide material satisfies the above-mentioned conditions, and has 1.31 μm and 1.55 μm.
m, which has low waveguide loss and excellent workability in the communication wavelength band of m.
It was found to be suitable for M production.

A perspective plan view and a sectional view taken along the longitudinal direction of the core of the structure of the refractive index modulation type optical waveguide grating are shown in FIG.
These are shown in FIGS. In the figure, reference numeral 21 denotes a refractive index modulation type grating, 22 denotes a core, 23 denotes a clad, 24 denotes a substrate, and 25 denotes a portion of the core to which a change in the refractive index is given. The core 22 can be manufactured by writing a grating pattern as a refractive index change by two-beam interference exposure, phase mask exposure, or electron beam drawing using a material whose refractive index changes by light or electron beam irradiation. For example, an acrylic polymer has an increased refractive index upon irradiation with an electron beam, and a benzene ring-containing silicone polymer has a UV index.
Since the refractive index is reduced by light irradiation, it is possible to manufacture a refractive index modulation type optical waveguide grating.

Since the optical waveguide grating 21 reflects light having a predetermined wavelength, an optical circuit for separating the reflected light is required to realize the function of the ADM.

FIG. 3 shows an ADM using a directional coupler of a polymer optical waveguide manufactured simultaneously with the grating. In the figure, reference numeral 30 denotes a tunable filter, 31 denotes a grating (wavelength filter), 32 denotes a directional coupler,
Reference numeral 33 denotes an input / output optical waveguide. A is an input port,
B indicates a drop port, and C indicates an add port. The symbols of these ports indicate the same ports in the following drawings. In the following figures, D indicates an output port.

On the other hand, FIGS. 4A and 4B show an ADM using an optical circulator connected outside the polymer waveguide grating. In the drawing, reference numeral 41 denotes a grating (wavelength filter), 42 denotes a clad, 43 denotes a thin film heater, 44 denotes a substrate, 45 denotes a heat insulating layer, and 46 denotes an optical circulator.

FIG. 5 shows the structure of an ADM for simultaneously multiplexing and demultiplexing a selected channel (wavelength λ _i ). In the figure, reference numeral 51 denotes a grating (wavelength filter), 52 denotes a directional coupler, 53 denotes an input / output optical waveguide,
Reference numeral 54 denotes a wavelength variable thin film heater, and 55 denotes a trimming thin film heater. In the ADM having the structure shown in FIG. 5, a grating wavelength filter 54 is formed in two arms of a Mach-Zehnder interferometer (MZI), and the entire structure has a symmetric structure. For demultiplexing, only the wavelength lambda _i of the two wavelength-multiplexed signal light separated by the directional coupler 52 is reflected by the two gratings 51, are output to the drop port B through the directional coupler 52. By inputting the optical signal of the wavelength lambda _i to the multiplexing also add port C on the same principle, performed at the same time. Here, it is necessary that the optical path length of the two arms and the position of the grating 51 be exactly symmetrical in the MZI. Therefore, the thin-film heater 55 for trimming is installed to correct the symmetry of the optical path length by the TO effect. I have.

The temperature control device is required to have a variable range of about 60 ° C. necessary for channel selection and temperature stability for obtaining wavelength stability. In order to keep the stability of the selected wavelength within 5% of the channel interval, the AD of 16 channels is required.
Temperature control of ± 0.1 ° C. at M is required. When controlling the temperature of the entire polymer optical waveguide, the optical waveguide is surrounded by a suitable heat insulating agent, and a heater or a piezo element in contact with the substrate and a feedback control by a temperature measuring element are used to control the temperature of ± 0.0.
Accuracy of 1 ° C can be realized. When the temperature of only the grating portion is controlled using a thin film heater, the stability of the wavelength can be realized by either of the following two methods. That is, the first method is a method in which the substrate temperature is kept constant by the same substrate temperature control system as described above, and a constant heating power depending on the selected channel is applied to the thin film heater. Second
In the method (1), a temperature measuring element such as a thermocouple is incorporated in a substrate, and a thin-film heater heating power required to obtain a target center wavelength is measured in advance as a function of the substrate temperature.
When operating, the heating power calculated from the two values of the substrate temperature and the wavelength setting is applied to the thin film heater.

Now, the present invention will be described in further detail with reference to Examples. The following examples are only preferred examples illustrating the present invention and do not limit the present invention.

[0022]

【Example】

Example 1 A tunable filter having the structure shown in FIG. 3 was manufactured. Two kinds of deuterated and fluorinated polymethacrylates having different copolymerization ratios prepared so as to have a refractive index difference of 0.3% (see JP-A-2-257865, "Plate-type plastic waveguide") are used as cladding materials. , As core material,
A buried polymer optical waveguide 33 was fabricated on a metal substrate. The cross-sectional size of the core was 8 μm × 8 μm, and the waveguide pattern was formed by connecting a directional coupler 32 having a coupling ratio of 50% and a straight waveguide. Using an electron beam lithography system, a refractive index difference of 2 × 10 ⁻⁴ and a period of 0.43 μm were formed on the straight waveguide portion.
A refractive index modulation type grating 31 having a length of 2 mm and a length of 2 mm was written to obtain a wavelength filter. The optical waveguide substrate was fixed to an aluminum block whose temperature was electronically controlled using a thermocouple and a piezo element.

The output of the LED light source in the 1.31 μm band was made incident on the input port A of the variable wavelength filter shown in FIG. 3 through an optical fiber, and the wavelength characteristic of the output of the drop port B was measured using an optical spectrum analyzer. 25 substrates
The transmission characteristics to the port B when controlled at 0 ° C. were as follows: center wavelength 1320 nm, bandwidth 0.5 nm, insertion loss 9 dB,
The extinction ratio was 18 dB. If the substrate temperature is 80 ° C,
The center wavelength was 1310 nm, and it was confirmed that this device operated as a wavelength tunable filter, and that the variable wavelength range was sufficiently large for ADM applications.

Example 2 A tunable filter having an ADM structure shown in FIG. 4 was prepared. It was adjusted so as to have a refractive index difference of 0.3%. Silicone polymer (Japanese Patent Application No. 7-859)
No. 79, "Polymer optical material and optical waveguide using the same") as a material of the clad 42 and a core material,
An embedded polymer optical waveguide was formed on the metal substrate 44. The cross-sectional size of the core was 8 μm × 8 μm, and the waveguide pattern was a straight line. This optical waveguide is irradiated with UV light having passed through a phase mask to obtain a refractive index difference of 5 × 10 ^-4 and a period of 0.1.
51 μm, 2 mm long refractive index modulated grating 4
I wrote 1. A metal thin film was deposited, and a thin film heater 43 was formed on the grating 41 by using photolithography and dry etching. Here, the width of the heater 43 was 30 μm and the length was 3 mm. Further, the same material as that of the clad 42 was further deposited to form a heat insulating layer 45. The wavelength filter optical circuit board was fixed to an aluminum block whose temperature was electronically controlled using a thermocouple and a piezo element. This wavelength tunable filter was connected to the optical circulator 46.

The output of the variable wavelength laser diode light source in the 1.55 μm band was incident on the input port A shown in FIG. 4 through an optical fiber, and the wavelength dependence of the output of the drop port B was measured. When the substrate is controlled at 25 ° C. and the thin-film heater 43 is not heated, the transmission characteristic to the port B has a center wavelength of 1
The wavelength was 560 nm, the bandwidth was 0.4 nm, the insertion loss was 4 dB, and the extinction ratio was 20 dB. When the thin film heater 43 was heated, the transmission center wavelength shifted to a shorter wavelength. The relationship between the heating power and the center wavelength at this time is shown in the graph of FIG. Further, the response time from when the heating power was changed on the step to when the light of a specific wavelength was transmitted and the light output was stabilized was measured and found to be 10 ms. It was confirmed that this device operated as a tunable filter, the tunable wavelength range was sufficiently large as an ADM, and the response speed was sufficiently fast.

Example 3 A wavelength variable filter having an ADM structure shown in FIG. 5 was prepared.

After depositing a lower cladding layer and a core layer on a metal substrate using the same materials as in Example 2, a resist is applied, and a grating pattern having a period of 0.51 μm and a length of 1 mm is formed using an electron beam lithography apparatus. Written in several places. After resist development, dry etching, core layer 0.8μ depth
m, a relief type grating 51 was prepared. After removing the resist, the core pattern is changed to M
A buried optical waveguide of ZI was manufactured. The position of the two gratings 51 was set at the center of the two arms of the MZI. A metal thin film was deposited, and a thin film heater 54 having the pattern shown in FIG. 5 was formed by using photolithography and dry etching. Here, the width of the wavelength selecting thin film heater 54 was 30 μm and the length was 2 mm. Further, the same material as the clad was further deposited to form a heat insulating layer. The wavelength filter optical circuit board was fixed to an aluminum block whose temperature was electronically controlled using a thermocouple and a piezo element.

The interval between 1543 nm and 1555 nm is 0.
An optical signal of 16 channels multiplexed at 8 nm was input to the input port A shown in FIG. The heating power and insertion loss of the thin film heater 54 when each channel signal was output to the drop port B, and the crosstalk from the non-selected channel were measured. At this time, the substrate was controlled at 25 ° C., and the thin-film heater for trimming 55 was controlled so that the output of the selected channel was maximized. FIG. 7 shows the heating power and insertion loss of the thin-film heater 54. The crosstalk was -20 dB or less in each case. Also,
A signal of the selected wavelength was input to the add port C, and it was confirmed that an insertion loss similar to the above-described drop characteristic was output to the output port D.

From the above, it was confirmed that the present device has practical characteristics as a 16-channel ADM.

Example 4 A wavelength tunable filter having the filter structure shown in FIG. 5 and having the overall structure shown in FIG. 8 was produced. 8, reference numeral 81 denotes an MZI type tunable filter, 82 denotes a heater control microcomputer, 83 denotes a DA converter, and 84 denotes an AD converter.

Adjusted so that the refractive index difference becomes 0.3% 2
After depositing a lower cladding layer and a core layer on a metal substrate using a kind of fluorinated UV resin (see JP-A-2-688, "Adhesive composition"), a resist is applied, and an electron beam lithography apparatus is used. A grating pattern having a period of 0.51 μm and a length of 1 mm was written in two places. After development of the resist, a relief type grating 51 having a depth of 0.8 μm was formed on the core layer by dry etching. Example 2 after removing the resist
A buried optical waveguide having a core pattern of MZI was manufactured in the same manner as in the above. The position of the two gratings 51 was set at the center of the two arms of the MZI. A thin film heater 54 similar to that of Example 3 was formed. further,
The same material as the clad was further deposited to form a heat insulating layer.
A wavelength filter optical circuit board was fixed to an aluminum block incorporating a thermocouple, and a device for controlling the heating power from the thermocouple output and the wavelength setting signal was fabricated. 1543nm to 1
The relationship between the heating power of the thin-film heater 54 and the substrate temperature when a 16-channel optical signal wavelength-division multiplexed to 555 nm at an interval of 0.8 nm was output to the drop port B was incorporated into a control microcomputer program.

The interval from 1543 nm to 1555 nm is 0.
When an optical signal of 16 channels wavelength-multiplexed at 8 nm was input and the wavelength setting signals were set to channels 1 to 16, it was confirmed that only the signal of the corresponding wavelength was output to the drop port. At this time, the maximum loss was 6 dB, and the crosstalk was -20 dB or less.

From the above, it has been confirmed that the present apparatus has practical characteristics as a 16CH ADM.

Example 5 A tunable filter using a polymer optical fiber grating having the structure shown in FIGS. 9A and 9B was manufactured. In the figure, reference numeral 91 is a polymer optical fiber grating, 92 is a refractive index modulation type fiber grating, 93 is a thin film heater, 94 is a pad for heater wiring, 95 is a metal substrate with a V groove, 96 is a holding plate with a thin film heater, and 97 is 3 shows a fixing adhesive.

Polymer optical fiber grating 91
Is an optical fiber made of acrylic resin (refractive index difference 0.3%,
A part of an outer diameter of 200 μm and a core system of 9 μm) was irradiated with UV light through a phase mask to write a refractive index modulation type grating 92 having a period of 0.60 μm and a length of 2 mm. A metal thin film is deposited on an acrylic substrate (1 mm thick), a thin film heater 93 having a length of 2.5 mm and a width of 50 μm and a wiring pad 94 are formed by photolithography and dry etching, and a pressing plate 96 is formed. did. As shown in FIG. 9B, a metal substrate 9 having a V-shaped groove
The above-mentioned polymer optical fiber grating 91 was placed on 5, sandwiched between holding plates 96, and fixed with an adhesive 97.

The output of the 1.55 μm band variable wavelength laser diode light source was incident on this polymer optical fiber, and the reflection loss characteristics were measured. When the metal substrate is controlled at 25 ° C. and the thin-film heater is not heated, the reflection characteristic has a center wavelength of 1
560 nm, bandwidth 0.4 nm, insertion loss 1.9 dB
Met. When the thin film heater was heated, the central reflection wavelength shifted to a shorter wavelength. When a maximum of 250 mW was applied, the reflection center wavelength was 1540 nm. Furthermore, the response time from when the heating power was changed stepwise until light of a specific wavelength was transmitted and the light output was stabilized was measured.
It was 0 ms. It was confirmed that this device operated as a tunable filter, and the tunable wavelength range was sufficiently large as ADM and low loss.

[0037]

According to the present invention, it is possible to manufacture an ADM having a simple structure, small size, low power consumption operation, and high speed response. This A
The use of DM enables the WDM system to be reduced in size and cost.

[Brief description of the drawings]

FIG. 1 shows a wavelength tunable filter of the present invention having a relief type grating structure, wherein (a) is a plan view,
(B) is a cross-sectional view along the longitudinal direction of the core.

FIGS. 2A and 2B show a wavelength tunable filter of the present invention having a refractive index modulation type grating structure, wherein FIG. 2A is a plan view and FIG. 2B is a cross-sectional view along a longitudinal direction of a core.

FIG. 3 is a plan view showing the configuration of a wavelength tunable filter of the present invention having an optical waveguide grating and a directional coupler.

4A and 4B show a wavelength tunable filter of the present invention having an optical waveguide grating and an optical circulator, wherein FIG. 4A is a plan view and FIG. 4B is a cross-sectional view along the optical grating.

FIG. 5 is a plan view of a tunable filter of the present invention having an optical waveguide grating and a Mach-Zehnder interferometer.

FIG. 6 is a graph showing the relationship between the heating power of a thin film heater and the center wavelength of demultiplexing in a tunable filter.

FIG. 7 is a graph showing a relationship between a channel number, a heating power of a thin film heater, and an insertion loss when each channel is demultiplexed in a wavelength tunable filter. This graph also shows the wavelength of each channel.

FIG. 8 is a block diagram showing an overall configuration of a wavelength tunable filter of the present invention including a wavelength setting device.

FIG. 9 shows a wavelength tunable filter of the present invention having an optical fiber grating and a heating device.
(A) is a side sectional view along an optical fiber grating, and (b) is a longitudinal sectional view perpendicular to (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Relief type grating 12 Core 13 Cladding 14 Substrate 21 Refractive index modulation type grating 22 Core 23 Cladding 24 Substrate 25 Portion of core which gave refractive index change 30 Wavelength variable filter 31 Grating (wavelength filter) 32 Directional coupler 33 Input / output optical waveguide 41 Grating (wavelength filter) 42 Cladding 43 Thin film heater 44 Substrate 45 Heat insulation layer 46 Optical circulator 51 Grating (wavelength filter) 52 Directional coupler 53 Input / output optical waveguide 54 Wavelength variable thin film heater 55 Trimming thin film heater 81 MZI type tunable filter 82 Heater control microcomputer 83 DA converter 84 A / D converter 91 Polymer optical fiber grating 92 Refractive index change Type fiber grating 93 thin film heaters 94 Heater wiring pads 95 V grooved metal substrate 96 with a thin film heater pressing plate 97 fixing adhesive A input port B drop port C add port D output port

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Tamamura 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Tetsuyoshi Ishii 3-19, Nishishinjuku, Shinjuku-ku, Tokyo No. 2 Nippon Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. A wavelength filter comprising a polymer optical waveguide or a polymer optical fiber having a grating structure, an optical circuit connected to the wavelength filter for inputting / outputting, multiplexing, or separating an optical signal; In a wavelength tunable filter including a temperature control device for arbitrarily controlling a temperature, a polymer optical waveguide characterized in that an optical signal of a specific wavelength is separated or mixed by changing a set temperature of the temperature control device. Tunable filter. 2. A local temperature control device which is close to a polymer optical waveguide or a polymer optical fiber having the grating structure, and which heats only the vicinity of the polymer optical waveguide or the polymer optical fiber having the grating structure. 2. The heater according to claim 1, wherein the heater is a heater.
4. The tunable polymer optical waveguide filter according to item 1. 3. The optical waveguide according to claim 1, wherein the polymer optical waveguide having the grating structure is an optical waveguide using a deuterated or deuterated fluorinated acrylic polymer, a silicone resin, or a UV-curable resin. Polymer optical waveguide wavelength tunable filter. 4. The optical waveguide according to claim 2, wherein the polymer optical waveguide having the grating structure is an optical waveguide using a deuterated or deuterated fluorinated acrylic polymer, a silicone resin, or a UV-curable resin. Polymer optical waveguide tunable filter.