Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
  • G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
  • G02B6/12009—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides
  • G02B6/12014—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides characterised by the wavefront splitting or combining section, e.g. grooves or optical elements in a slab waveguide
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
  • G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
  • G02B6/12009—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides
  • G02B6/12026—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides characterised by means for reducing the temperature dependence
  • G02B6/1203—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides characterised by means for reducing the temperature dependence using mounting means, e.g. by using a combination of materials having different thermal expansion coefficients
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
  • G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
  • G02B6/12009—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides
  • G02B6/12033—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides characterised by means for configuring the device, e.g. moveable element for wavelength tuning

Definitions

• the present invention relates to an arrayed waveguide type diffraction grating used as an optical multiplexer / demultiplexer in, for example, wavelength division multiplexing optical communication, and a method of correcting a light transmission center wavelength thereof.
• Optical wavelength division multiplexing is, for example, multiplexing and transmitting a plurality of lights having different wavelengths.
• the light transmitting device is provided, for example, on the light receiving side, and is used to extract light for each wavelength from multiplexed light to be transmitted.
• FIG. 11 shows an example of a light transmitting device.
• This light transmitting device is an arrayed waveguide type diffraction grating (AWG; Arrayed WaveguidideGrating) of a flat plate optical waveguide circuit (PLC; P1 anarLighthtwaveCircuit).
• the array waveguide type diffraction grating is formed by forming a waveguide forming region 10 having a waveguide configuration as shown in FIG. 1 on a substrate 1 such as a silicon glass or the like.
• the waveguide configuration of the optical waveguide type diffraction grating includes one or more optical input waveguides 2 and a first slab waveguide 3 connected to the output side of the optical input waveguide 2.
• the output side of the first slab waveguide 3 is connected to an arrayed waveguide 4 composed of a plurality of arranged side-by-side channel waveguides 4a.
• the second slab waveguide 5 is connected to the exit side of the ray waveguide 4, and a plurality of juxtaposed optical output waveguides 6 are connected to the exit side of the second slab waveguide 5. .
• the array waveguide 4 transmits the light guided from the first slab waveguide 3.
• the lengths of the overlapping channel waveguides 4a are different from each other by ⁇ L.
• the optical output waveguides 6 are provided corresponding to the number of signal lights having different wavelengths to be split or multiplexed by, for example, an arrayed waveguide type diffraction grating.
• a large number of channel waveguides 4a are provided, for example, 100 lines.
• the numbers of these optical output waveguides 6, channel waveguides 4a and optical input waveguides 2 are simply shown.
• An optical fiber (not shown) on the transmission side is connected to the optical input waveguide 2 so that wavelength-division multiplexed light is introduced.
• This wavelength multiplexed light passes through the optical input waveguide 2 and enters the first slab waveguide 3.
• the wavelength multiplexed light incident on the first slab waveguide 3 spreads due to the diffraction effect of the first slab waveguide 3, enters the array waveguide 4, and propagates through the array waveguide 4.
• the light that has propagated through the array ⁇ waveguide 4 reaches the second slab waveguide 5, is further condensed on the optical output waveguide 6, and is output.
• the lengths of the adjacent channel waveguides 4 a of the array waveguide 4 are different from each other by a set amount, there is a shift in the phase of each light after propagating through the array waveguide 4.
• the wavefront of the condensed light is tilted according to the amount of deviation, and the position of condensing is determined by the tilt angle.
• the light condensing positions of the lights having different wavelengths are different from each other.
• the optical output waveguides 6 By forming the optical output waveguides 6 at the respective light condensing positions, light having different wavelengths (demultiplexed light) can be output from the different optical output waveguides 6 for each wavelength.
• the arrayed waveguide grating demultiplexes light of one or more wavelengths from the multiplexed light having a plurality of different wavelengths input from the optical input waveguide 2 and outputs the light from each optical output waveguide 6. It has an optical demultiplexing function for output.
• the center wavelength of the demultiplexed light is determined by the difference in length (AL) between the adjacent channel waveguides 4a of the array waveguide 4 and the effective refractive index (equivalent refractive index) n of the array waveguide 4. Proportional.
• the arrayed waveguide grating satisfies the relationship of (Equation 1).
• n s is the first slab waveguide and the second slab waveguide equivalent refractive Oriritsu, n. Is the equivalent refractive index of the array waveguide.
• ⁇ is the diffraction angle
• m is the diffraction order
• d is the distance between adjacent channel waveguides 4a, or the transmission center wavelength of light output from each optical output waveguide.
• the wavelength ⁇ u is generally represented by an array waveguide Is called the center wavelength of the diffraction grating.
• the arrayed waveguide type diffraction grating can be used as a wavelength division multiplexing demultiplexer for wavelength division multiplexing transmission.
• wavelength multiplexed light with wavelengths of 1, 2, 3, 2, ⁇ ⁇ - ⁇ ( ⁇ is an integer of 2 or more) is input from one optical input waveguide 2.
• the light of each of these wavelengths is spread by the first slab waveguide 3 and reaches the array 4.
• the light of each wavelength passes through the second slab waveguide 5 and is condensed at different positions depending on the wavelength as described above.
• Light of each wavelength is incident on a different optical output waveguide 6, passes through each optical output waveguide 6, and is output from the output end of the optical output waveguide 6.
• optical fibers for optical output to the emission end of each optical output waveguide 6, the light of each wavelength is extracted through this optical fiber.
• optical fibers are connected to each of the optical output waveguides 6 and the optical input waveguide 2 described above, for example, an optical fiber array in which the connection end faces of the optical fibers are arranged and fixed in a one-dimensional array is prepared. Then, this optical fiber array is fixed to the connection end face side of the optical output waveguide 6 and the optical input waveguide 2, and the optical fiber is connected to the optical output waveguide 6 and the optical input waveguide 2.
• the light transmission characteristics of the light output from each optical output waveguide 6 that is, the wavelength characteristics of the transmitted light intensity of the array waveguide type diffraction grating are, for example, shown in FIG. It becomes as shown in. As shown in this figure, the light transmission characteristics of the light output from each light output waveguide 6 are centered on each light transmission center wavelength (for example, 1, ⁇ 2, ⁇ 3, ⁇ ⁇ ). However, the light transmission characteristic becomes smaller as the wavelength shifts from the corresponding light transmission center wavelength.
• FIG. 13 is a diagram in which examples of output spectra from the respective optical output waveguides 6 are overlapped.
• the light transmission characteristics do not always have one maximum value as shown in FIG. 12, but have two or more maximum values as shown in FIG. In some cases.
• arrayed waveguide gratings use the principle of reciprocity (reversibility) of light. Since it is used, it has the function of an optical demultiplexer as well as the function of an optical demultiplexer.
• the optical multiplexing for example, contrary to FIG. 11, light of a plurality of wavelengths different from each other is incident from each optical output waveguide 6 of the arrayed waveguide type diffraction grating for each wavelength. It is performed by.
• the light incident from each optical output waveguide 6 passes through the reverse propagation path, and is multiplexed through the second slab waveguide 5, the array waveguide 4, and the first slab waveguide 3, and The light is emitted from the optical input waveguide 2.
• the waveguide formation region of the above array waveguide type diffraction grating is originally formed mainly of a silica glass material.
• the light transmission center wavelength of the arrayed waveguide grating shifts depending on the temperature due to the temperature dependency of the quartz glass material.
• This temperature dependency is obtained by differentiating the above (Equation 2) by the temperature change amount T, where T is the temperature change amount of the arrayed waveguide grating, and is given by (Equation 3). Is shown
• Equation 3 the first term on the right side is the temperature dependence of the effective refractive index of the array waveguide 4, and the second term on the right side is the The change in length is shown.
• FIG. 14 is a diagram schematically showing the temperature dependence of the light transmission center wavelength based on the measurement results of the light transmission characteristics output from one optical output waveguide 6-shown in FIG.
• the central wavelength of light transmission shifts to the longer wavelength side as the temperature of the arrayed waveguide grating becomes lower.
• the center wavelength of light transmission shifts to ⁇ wavelength as the temperature of the array-waveguide grating decreases.
• the refractive index of the glass forming the waveguide increases, which increases the first term on the right-hand side of (Equation 3).
• the length of the array waveguide 4 becomes physically longer due to the thermal expansion of the substrate 1 and the waveguide material. That is, the second term on the right side of (Equation 3) becomes large. Therefore, when the temperature rises, the optical path length perceived by the light passing through the array waveguide 4 becomes longer, so that the light transmission center wavelength shift as described above occurs.
• FIG. 14 shows the temperature change of the transmission characteristics of the light output from one optical output waveguide 6, but in the arrayed waveguide type diffraction grating, the output from all the optical output waveguides 6 is shown.
• the transmitted light characteristic exhibits the same shift characteristic. That is, the light output from all the optical output waveguides 6 is shifted by the same shift amount in the same shift direction with the same light transmission center wavelength depending on the temperature.
• Ru n e 1 4 5 1 der at the wavelength 1 5 5 m.. .
• Array waveguide gratings currently used are often used to split or multiplex wavelength-division multiplexed light in a wavelength band centered at 1550 nm. . Therefore, the temperature dependence of the light transmission center wavelength of a conventional general array waveguide type diffraction grating in a wavelength band centered at a wavelength of 1550 nm is determined. In that case, the value of the temperature dependence of the light transmission center wavelength is about 0.01 nm ° C.
• the center wavelength of light transmitted from each optical output waveguide 6 is shifted by 0.5 nm. Also.
• the temperature of the arrayed waveguide grating was 70. If the C changes, the shift amount of the light transmission center wavelength will be 0.7 nm.
• an arrayed waveguide type diffraction grating provided with a temperature adjusting means for keeping the temperature of the arrayed waveguide type diffraction grating constant so that the light transmission center wavelength does not change with temperature
• This temperature adjusting means is provided with, for example, a Peltier element or a heater. These temperature control means control the array waveguide type diffraction grating to be maintained at a predetermined set temperature.
• FIG. 15 shows a configuration in which a Peltier element 26 is provided on the substrate 1 side of the arrayed waveguide type diffraction grating.
• the array waveguide type diffraction grating shown in the figure is for adjusting the temperature of the array waveguide type diffraction grating based on the detection temperature of the thermistor 40 so as to keep the temperature constant.
• 41 indicates a conductor
• 12 indicates a soaking plate.
• the heater is maintained at a high temperature so that the temperature of the arrayed waveguide grating is kept constant.
• the configuration in which the temperature adjusting means is provided by keeping the temperature of the arrayed waveguide diffraction grating constant, expansion and contraction of the substrate 1 and a change in the equivalent refractive index of the core due to the temperature can be suppressed. Therefore, the configuration in which the temperature adjusting means is provided can solve the problem of the temperature dependence of the light transmission center wavelength.
• thermocouple A control, a thermostat for control, and a thermocouple are required.
• the array waveguide type diffraction grating having the temperature control means cannot accurately suppress the central wavelength shift of light transmission due to misalignment of the temperature control means.
• array waveguide type diffraction gratings are extremely precise during manufacture. Is done. Therefore, in the conventional arrayed waveguide type diffraction grating, apart from the temperature dependence of the light transmission center wavelength during use, the light transmission center wavelength deviates from the set wavelength due to manufacturing errors (such as manufacturing variations). Also had the problem that Therefore, development of an inexpensive array waveguide type diffraction grating that can detect both the deviation of the light transmission center wavelength from the design wavelength and the temperature dependence has been required. Disclosure of the invention
• An arrayed waveguide type diffraction grating having a first configuration includes at least one optical input waveguide, a first slab waveguide connected to an output side of the optical input waveguide, and the first optical waveguide.
• a waveguide structure having a waveguide and a plurality of optical output waveguides connected in parallel on the emission side of the second slab waveguide, wherein the first slab waveguide and the second slab are formed.
• At least one of the waveguides is separated at an intersecting plane intersecting the light path passing through the slab waveguide to form a separated slab waveguide, and at least one side of the separated separated slab waveguide is the separation surface.
• Array-type by sliding along the temperature depending on the temperature A slide moving member for reducing the temperature dependence of the light transmission center wavelength of the folded grating is provided, and the length of the slide moving member is increased by plastic deformation in the sliding direction of the arrayed waveguide type diffraction grating.
• the array waveguide type diffraction grating of the second configuration of the present invention is characterized in that, in addition to the first configuration, Sliding movement The plastic deformation of the U material is performed by applying ⁇ stress to the sliding member.
• the plastic deformation of the slide moving member is caused by applying a tensile stress to the slide moving member. It is characterized by being applied.
• the first slab waveguide is connected to the exit side of at least one optical input waveguide, and the first slab waveguide is connected to the first slab waveguide.
• the output side is connected to a plurality of side-by-side waveguides, each of which is provided with a plurality of channel waveguides that transmit light derived from the first slab waveguide and have different lengths and are arranged side by side.
• a second slab waveguide is connected to the output side of the ray waveguide, and a plurality of optical output waveguides arranged in parallel are connected to the output side of the second slab waveguide.
• At least one of the first slab waveguide and the second slab waveguide is separated at a crossing plane intersecting a light path passing through the slab waveguide to form a separated slab waveguide; At least one side of the separated separated slab waveguide is slid along the separation surface depending on the temperature.
• a slide moving member is provided for lowering the temperature dependence of the light transmission center wavelength of the arrayed waveguide type diffraction grating by moving the slide, and the slide moving member in the slide direction of the slide moving member is provided.
• a dent or hole is formed in the displacement area, and a fitting member having a wide-diameter portion wider than the opening of the dent or hole is fitted into the dent or hole, whereby the slide is formed. It is characterized in that the length of the movable member is a length for detecting the deviation of the center wavelength of light transmission of the arrayed waveguide grating from the set wavelength.
• the array waveguide type diffraction grating of the fifth configuration of the present invention is characterized in that, in addition to the fourth configuration, the fitting member is a tapered screw whose diameter is reduced toward the distal end. I do.
• the array waveguide type diffraction grating of the sixth configuration according to the present invention is characterized in that, in addition to any one of the first to fifth configurations, the slide moving material is formed of metal. It is characterized by having. Further, the light transmission center wavelength correction method for an arrayed waveguide type diffraction grating of the seventh configuration of the present invention is characterized in that at least one optical input waveguide is contacted with the output side of the optical input waveguide.
• An array waveguide comprising: a first slab waveguide; a plurality of channel waveguides which are in contact with the emission side of the first slab waveguide and have a plurality of parallelly arranged channel waveguides having different lengths from each other; A waveguide configuration having a second slab waveguide connected to the output side of the waveguide and a plurality of optical output waveguides connected in parallel on the output side of the second slab waveguide is formed on a substrate.
• An array waveguide formed as a separated slab waveguide by separating at least one of the first slab waveguide and the second slab waveguide at an intersection plane intersecting a light path passing through the slab waveguide. At least one side of the separated separation slab waveguide to the separation surface.
• a slide moving member that reduces the temperature dependence of the light transmission center wavelength of the arrayed waveguide type diffraction grating by moving the slide depending on the temperature is provided, and the slide moving member is plastically deformed. Then, by moving at least one side of the separation slab waveguide along the separation surface, the light transmission center wavelength of the array waveguide type diffraction grating is set as a set wavelength.
• the method of correcting the light transmission center wavelength of the arrayed waveguide type diffraction grating of the eighth configuration according to the present invention may further include the plastic deformation of the slide moving member in addition to the seventh structure. It is characterized by performing by applying compressive stress.
• the method of correcting the optical transmission center wavelength of the arrayed waveguide type diffraction grating of the ninth configuration according to the present invention is characterized in that, in addition to the seventh configuration described above, the plastic deformation of the slide transfer U material is controlled by the slide movement.
• a special feature is to perform the process by applying tensile stress to the material.
• the method of correcting the light transmission center wavelength of the arrayed waveguide type diffraction grating of the tenth configuration of the present invention comprises the steps of: providing at least one optical input waveguide; A first slab waveguide connected to the first slab waveguide, and an array waveguide connected to the output side of the first slab waveguide and having a plurality of parallelly arranged channel waveguide forces having different lengths from each other; An optical waveguide having a second slab waveguide connected to the output side of the array waveguide and a plurality of optical output waveguides connected in parallel to the output side of the second slab waveguide is provided on a substrate.
• An array conductor formed as a separated slab waveguide by separating at least one of the first slab waveguide and the second slab waveguide at an intersection plane intersecting a light path passing through the slab waveguide.
• a free waveguide type diffraction grating is obtained.
• a recess or a hole is formed in a displacement region in the slide direction of the slide moving member, and a fitting member having a wider diameter than the opening of the recess or the hole is fitted into the recess or the hole.
• the method of correcting the light transmission center wavelength of the array waveguide type diffraction grating of the eleventh configuration includes the above-described array waveguide type diffraction grating in addition to any one of the seventh to tenth configurations. While monitoring the light transmission center wavelength of the diffraction grating, the slide moving material is used so that the monitored light transmission center wavelength becomes the set wavelength.
• the inventor of the present invention is characterized in that it moves along the separation plane of the slab waveguide.
• the present inventors We focused on dispersion characteristics.
• Equation 4 L f is the focal length of the second slab waveguide, and ng is the fresh refractive index of the array waveguide. Note that the group refractive index n g of the array waveguide is given by (Equation 5) by the equivalent refractive index n c of the array waveguide.
• Equation 4 is obtained by arranging and forming the input end of the optical output waveguide at a distance dX in the X direction from the focal point ⁇ of the second slab waveguide. It means that it is possible to extract the light that has passed.
• Equation 4 the relationship of (Equation 4) is similarly established for the first slab waveguide 3.
• the center of the focal point of the first slab waveguide 3 is defined as a point ⁇ ′, and a point at a position shifted from the point 0 ′ by a distance dX ′ in the X direction is defined as a point P ′.
• the output wavelength will shift by d'.
• Equation 6 Note that, in (Equation 6), ⁇ is the focal length of the first slab waveguide. is there. This (Equation 6) is obtained by arranging the output end of the optical input waveguide at a position d X ′ away from the focal point ⁇ ′ of the first slab waveguide in the X direction, and This means that it is possible to extract light with different wavelengths by d ⁇ 'from the formed optical output waveguide.
• the deviation of the center wavelength of light transmission is corrected by the following equation. This can be achieved by shifting the position of the output end of the optical input waveguide by the distance dx ′ in the X direction. By this operation, for example, light without wavelength shift can be extracted from the optical output waveguide formed at the focal point. Further, since the above-described action similarly occurs for other optical output waveguides, the above-described optical transmission center wavelength shift ⁇ can be corrected (eliminated).
• the first slab waveguide and the second slab waveguide is separated by a plane intersecting a light path passing through the slab waveguide.
• the first slab waveguide is separated.
• the side of the separated slab waveguide (including the optical input waveguide) connected to the optical input waveguide is moved along the separation surface by a slide moving member. And slide it. Then, the respective light transmission center wavelengths can be shifted by the slide movement.
• the slide-moving member reduces the temperature-dependent variation of each of the light transmission center wavelengths so that the temperature-dependent variation (wavelength shift) ⁇ of each of the light transmission center wavelengths becomes equal to d ⁇ .
• the separation slab waveguide and the optical input waveguide are moved along the separation plane in the direction. This makes it possible to eliminate the temperature-dependent wavelength shift of the light transmission center, which is dependent on the temperature.
• the position of the output end of the optical input path is changed.
• the focal length L t ′ of light propagating in the first slab waveguide slightly changes
• the focal length of the first slab waveguide in an arrayed waveguide grating is on the order of mm.
• the amount of movement of the output end position of the optical input waveguide, which moves to correct the light transmission center wavelength of the arrayed waveguide grating is on the order of several ui to several 10 m. That is, the amount of movement of the output end position of the optical input waveguide is much smaller than the focal length of the first slab waveguide.
• Equation 3 The temperature dependence of the light transmission center wavelength (the amount of shift of the light transmission center wavelength due to temperature) is expressed by the above (Equation 3), and the temperature change amount T is used to calculate the light transmission center wavelength shift amount ⁇ . It can be expressed by (Equation 7).
• the separated slab waveguide and the light input of the first slab waveguide are moved along the separation plane by the slide moving member by the position correction amount d X ′ represented by (Equation 8).
• the waveguide is slid depending on the temperature. This slide movement makes it possible to eliminate the temperature-dependent central wavelength shift of the light transmission.
• the arrayed waveguide type diffraction grating of the present invention can be configured such that, when the separation slab waveguide side connected to the optical input waveguide is slid along the separation surface, the respective light transmission center wavelengths are obtained. Can be shifted.
• the present invention changes the length of the slide moving member in the slide moving direction by plastic deformation or the like of the slide moving member to slide the separated slab waveguide along the separation surface. I did it. Therefore, according to the present invention, the light transmission center wavelength of the arrayed waveguide diffraction grating can be shifted to the set wavelength.
• the plastic deformation of the slide moving member for example, slide it to the moving member shall be carried out or apply tension stress Hikitsu or applying a compressive stress c
• the slide moving member slides the moving direction of the The length can also be changed by fitting the fitting member into a dent or hole formed in the slide moving member.
• the arrayed waveguide type diffraction grating can be used.
• the center wavelength of the light transmission of the diffraction grating can be almost set to the set wavelength.
• the slide moving member slides the separated slab precious path depending on the temperature. Therefore, for example, by this slide transfer, the temperature of the light transmission center length of the array 3 ⁇ 4 waveguide grating ik If the performance is reduced, an excellent arrayed-waveguide grating can be obtained in which the central wavelength of light transmission becomes almost the set wavelength at any temperature within the operating temperature range.
• the arrayed waveguide grating is formed by utilizing the reciprocity of light. Therefore, the second slab waveguide side is separated, and at least one side of the separated separated slab waveguide is moved along the separation surface in a direction to reduce the temperature-dependent variation of each light transmission center wavelength. The same effect can be obtained when a slide moving member for sliding is provided.
• the light transmission center wavelength can be set to the set wavelength at any temperature within the operating temperature range.
• FIG. 1A is a plan view showing a main configuration of an array waveguide type diffraction grating according to a first embodiment of the present invention
• FIG. 1B is a side view thereof
• FIG. FIG. 1 is an explanatory view showing a plastic deformation operation of a slide moving member provided in one embodiment by a plan view
• FIG. 1D is a side view thereof
• FIG. 2 is an array of the first embodiment.
• FIG. 3 is an explanatory view schematically showing an example of a light transmission center wavelength correction step of a waveguide type diffraction grating.
• FIG. 3 is applied to correction of a light transmission center wavelength of an arrayed waveguide type diffraction grating of the first embodiment.
• FIG. 4 is an explanatory view showing an example of a jig.Fig. 4 shows a state before the light transmission center wavelength of the arrayed waveguide type diffraction element of the first embodiment is corrected, and a state when a stress for performing the correction is applied.
• 7 is a graph showing light transmission characteristics after correction of the light transmission center wavelength.
• FIG. 5A is a plan view showing a main configuration of a second embodiment of the arrayed waveguide type diffraction grating according to the present invention
• FIG. 5B is a side view thereof
• FIG. FIG. 5D is an explanatory diagram showing the plastic deformation operation of the slide transfer member provided in the second embodiment by a plane m
• FIG. 5D is a side view thereof
• FIG. 7A is an explanatory diagram schematically showing an example of a light transmission center wavelength correcting step of an arrayed waveguide type diffraction grating according to a second embodiment.
• FIG. 7A is a diagram showing an arrayed waveguide type diffraction grating of the present invention.
• FIG. 7A is a diagram showing an arrayed waveguide type diffraction grating of the present invention.
• FIG. 7B is a plan view showing a main part configuration of another embodiment, FIG. 7B is a side view thereof, and FIG. 7C is provided in the embodiment shown in FIGS. 7A and 7B.
• FIG. 7D is an explanatory view showing, by a plan view, a plastic deformation operation of the slide moving member, and FIG. 7D is a side view thereof.
• FIG. 8A is a plan view showing a main configuration of another embodiment of the arrayed waveguide type diffraction grating of the present invention
• FIG. 8B is a side view thereof
• FIG. 8A and 8B are explanatory views showing a plastic deformation operation of a slide moving member provided in the embodiment shown in FIG. 8B by a plan view
• FIG. 8D is a side view thereof
• FIG. FIG. A is a plan view showing the configuration of a main part of another embodiment of the arrayed waveguide grating of the present invention
• FIG. 9B is a side view thereof
• FIG. 9A and 9B are explanatory views showing a plastic deformation operation of a slide moving member provided in the embodiment shown in FIGS. 9A and 9B by a plan view
• FIG. 9D is a side view thereof.
• FIG. 10 is an explanatory diagram showing the relationship between the light transmission center wavelength shift and the positions of the optical input waveguide and the optical output waveguide in the arrayed waveguide type diffraction grating
• FIG. FIG. 12A is an explanatory diagram showing a ray waveguide type diffraction grating
• FIG. 12A is a graph showing an example of light transmission characteristics of light output from one optical output waveguide of the ray waveguide type diffraction grating
• FIG. 12B is a graph showing another example of the light transmission characteristics of light output from one optical output waveguide of the arrayed waveguide grating.
• FIG. 13 is a graph in which light transmission characteristics of light output from the optical output waveguides of the array waveguide type diffraction grating are superimposed.
• FIG. 14 is a graph showing the array waveguide type diffraction grating.
• FIG. 15 is a graph showing an example of a shift in light transmission characteristics of light output from one optical output waveguide of a diffraction grating depending on temperature.
• FIG. 4 is an explanatory diagram showing an arrayed waveguide diffraction grating configured by providing an element. BEST MODE FOR CARRYING OUT THE INVENTION
• FIG. 1A and 1B schematically show a schematic view of a first embodiment of an arrayed waveguide grating according to the present invention.
• Figure 1 1 is a plan view and Figure 1B is a side view.
• the arrayed waveguide type diffraction grating of the first embodiment also has a core waveguide configuration formed on the substrate 1 like the arrayed waveguide type diffraction grating of the conventional example.
• the first slab waveguide 3 is a cross-separation plane of a plane (separation plane) intersecting a light path passing through the first slab waveguide 3. Separated by eight.
• the cross separation surface 8 is provided from one end side (left end side in the figure) of the waveguide forming region 10 to a middle part of the waveguide forming region.
• a non-intersecting separating surface 18 that does not intersect with the first slab waveguide 3 is formed so as to communicate with the intersecting separating surface 8.
• the non-intersecting separating surface 18 is provided to be orthogonal to the intersecting separating surface 8, but the non-intersecting separating surface 18 may not be orthogonal to the intersecting separating surface 8.
• FIG. 1A describes an embodiment in which the non-intersecting separating plane 18 and the intersecting separating plane 8 are orthogonal to each other.
• the crossing separation plane 8 and the non-crossing separation plane 18 form a waveguide formation area 10, a first waveguide formation area 10 a including the separation slab waveguide 3 a on one side, and a separation on the other side. It is separated into a second waveguide forming region 10b including the slab waveguide 3b.
• the interval between the portions A (the interval between the non-intersecting separation planes 18) shown in FIG. 1A is: about L0m, and the interval between the B cities shown in FIG. Is about 25 m.
• the first waveguide formation I region 10a is cross-separated from the second waveguide formation region 10b depending on the temperature of the arrayed waveguide type diffraction grating.
• a slide moving member 17 that moves along the surface 8 is provided. The slide moving member 17 is configured to perform this slide movement in a direction to reduce the temperature dependence of the light transmission center wavelength of the arrayed waveguide type diffraction grating.
• the slide moving member 17 is formed of a copper plate which is a metal having a higher coefficient of thermal expansion than the substrate 1. Thermal expansion coefficient of copper is 1. 6 5 X 1 0- 5 (1 / K).
• the adhesive 30 is provided below the slide moving member 17, and the slide moving member 17 is fixed to a fixing portion of the waveguide forming regions 10 a and 10 b.
• each parameter in the waveguide configuration is configured as follows.
• the focal length L i ′ of the first slab waveguide 3 is equal to the focal length L f .
• the second slab waveguide 5 is 9 mm (900 m).
• the equivalent refractive index of the first slab waveguide 3 and the equivalent refractive index of the second slab waveguide 5 are both n s , and the value is equal to the wavelength of 1.5501.
• it is 1.4.53.
• the optical path length difference ⁇ L of the array waveguide 4 is 65.2 um, and the distance d between the arrayed waveguides 4 is 15 ⁇ m.
• the diffraction order m of the array waveguide type diffraction grating is 61, and the array conductivity:
• the equivalent bending and bending factor n L of the waveguide 4 is 1.451 for light with a wavelength of 1.55 ⁇ m.
• the group refractive index n ⁇ of the ray waveguide 4 is hand :! 4 7 5.
• the amount of movement of the output end of the optical input waveguide 2 accompanying the movement of the separated slab waveguide 3a is denoted by d X.
• dX ' 25.6 d ⁇ '. Therefore, in order to change the light transmission center wavelength by 0.1 ⁇ , it is sufficient to change the length of the thermal expansion coefficient utilization region in the longitudinal direction of the slide moving member 17 by 2.56 am. .
• the coefficient of thermal expansion of the substrate 1 is much smaller than the coefficient of thermal expansion of the slide moving member 17, it is ignored and the temperature dependence of the center wavelength of the optical waveguide type diffraction grating is 0.0.
• the optimal value of the fixed position interval (J in the figure) of the slide moving member 17 was found by experiments, and it was found that the value should be 20 nm. Do you get it. Therefore, in the first embodiment, the total length of the slide moving member 17 and the length of the fixed position interval are determined so that the length J is 20 mm, and an array waveguide type diffraction grating is manufactured. did.
• holes 38 and 39 are provided in the slide moving member 17. Then, as shown by arrows E in FIGS. 1C and 1D, a tensile stress is applied to the slide moving member 17 to move the sliding member 17 in the above-described sliding direction (see FIG. X direction).
• the slide moving member 17 is provided with a hole 39 so that it can be easily deformed. Also, the position of the hole 39 is in the slide moving material 17. Since it is the center, the sliding member 17 can be expanded and contracted while maintaining the strength in the bending direction of the sliding member 17.
• FIGS. 1C and ID show exaggerated changes in the length of the sliding moving material 17. That is, the amount of change in the interval between the non-intersecting separation planes 18 is exaggerated. However, this change is actually much smaller than the amount shown in these figures.
• the plastic deformation of the slide moving material 17 is performed, for example, by a vise 49 as a stress applying means shown in FIG. That is, the adjustment of the tensile stress applied to the slide moving member 17 is performed by inserting the pins 55, 56 provided in the vice 49 into the holes 38 of the slide moving member 17, respectively. . Adjustment of the tensile stress applied to the slide moving material 17 is performed by adjusting the position of the pin 56 by operating the knobs 57 and 56 with the pins 55 and 56 inserted. Done.
• a semiconductor optical amplifier (ASE) is connected to the optical input waveguide 2 of the arrayed waveguide type diffraction grating. ) 4 2 was connected.
• an optical spectrum analyzer 43 was connected to one of the optical output waveguides 6 of the array waveguide type diffraction grating. Then, while monitoring the light transmission center wavelength of the arrayed waveguide type diffraction grating with the optical spectrum analyzer 43, a tension force of 1% is applied to the slide moving member 17 in the direction shown by the arrow in the figure. Then, plastic deformation of the sliding moving material 17 was performed.
• the characteristic line a in Fig. 4 shows the light transmission loss characteristics (light transmission spectrum) of the arrayed waveguide type diffraction grating before the application of the tensile stress to the member 17). ing.
• the tensile force is released when the center wavelength of light transmission of the arrayed waveguide type diffraction grating changes by about 0.5 nm. Then, the vise 49 was removed from the slide moving member 17. Further, the light transmission spectrum of the arrayed waveguide grating after the release of the tensile stress was measured, and the result indicated by the characteristic line c in the figure was obtained.
• the light transmission spectrum at the time of the application of the tensile stress or after the release of the tensile stress has a shift in the central wavelength of light transmission as compared to before the application of the tensile stress.
• the optical characteristics there was no change in the optical characteristics.
• the center wavelength shift of light transmission when the tensile stress was released was shifted.
• the sample volume was 0.1 nm. This means that the slide moving member 17 has been plastically deformed by 0.1 nm in terms of the light transmission center wavelength shift amount of the arrayed waveguide type diffraction grating. It also means that the light transmission center wavelength shift amount (change amount) combining this plastic deformation and elastic deformation during tension was -0.5 nin.
• the array waveguides in order to obtain a desired amount of change in the center wavelength of light transmission, the array waveguides must be applied when the tensile stress is applied to the slide moving material 17 and when the tensile stress is released.
• the amount of change from the initial value of the light transmission center wavelength of the diffraction grating may be obtained in advance.
• the light transmission center wavelength can be set to the dalit wavelength.
• the array waveguide type diffraction grating T- has the same temperature dependence of the wavelength (light transmission center wavelength) of the light output from each optical output waveguide 6. Therefore, as described above, when the central wavelength of light transmission from one optical output waveguide 6 is a grid wavelength, the central wavelength of light transmission from another optical output waveguide 6 is also a grid wavelength. .
• the first embodiment is configured as described above, and as shown by an arrow E in FIGS. 1C and 1D, a slide stress is applied to the slide moving member 17 by applying a tensile stress. Plastic deformation.
• the length of the slide moving member 17 is set to the length for detecting the deviation of the center wavelength of the light transmission of the arrayed waveguide grating from the set wavelength. did. Therefore, in the first embodiment, the light transmission center wavelength of the arrayed waveguide grating can be set to the set wavelength (grid wavelength) with a very simple configuration.
• the slide moving member 17 expands and contracts depending on the temperature. Due to this expansion and contraction, the separation slab waveguide 3a slides along the separation surface 8 in a direction to reduce the temperature-dependent variation of the optical transmission center wavelength of the arrayed waveguide type diffraction grating.
• the direction in which the temperature dependence of each light transmission center wavelength is reduced is the direction of arrow C or the direction of arrow D in FIGS. 1A and 1B.
• the first embodiment can be a so-called temperature-independent array waveguide type diffraction grating that does not depend on temperature.
• the first embodiment can be an excellent array waveguide type diffraction grating in which the light transmission center wavelength becomes the set wavelength (grid wavelength) at any temperature within the operating temperature range.
• the optical transmission center wave was measured.
• the amount of shift (shift) of the length was about 0.01 nm or less.
• the optical transmission center wavelength hardly shifts, and the optical waveguide type diffraction grating of the first embodiment does not shift. It was confirmed that this was an excellent array waveguide type diffraction grating whose center wavelength was always the grid wavelength.
• FIGS. 5A and 5B schematically show schematic diagrams of a second embodiment of the arrayed waveguide grating according to the present invention.
• the second embodiment is configured in substantially the same manner as the first embodiment, and in the description of the second embodiment, the overlapping description with the first embodiment will be omitted or simplified.
• the second embodiment is different from the first embodiment in that a compressive stress is applied to the sliding member 17 so that the sliding member 17 is moved in the sliding direction. (X direction in the figure). This compressive stress is applied by sandwiching the sliding member 17 from the left and right sides as shown in FIGS. 5C and 5D, and applying a stress in the direction indicated by arrow E in these figures. .
• the slide moving member 17 is not provided with the holes 38, 39.
• the length of the slide moving member 17 is changed by a plastic deformation in the slide moving direction to reduce the deviation of the light transmission center wavelength of the array waveguide type diffraction grating from the set wavelength to a long wavelength.
• the length to be captured on the side is set.
• the length change amount of the slide moving member 17 is exaggerated. That is, the amount of change in the spacing between the non-intersecting separation planes 18 is exaggerated. However, the amount of change in the length of the slide moving member 17 is sometimes much smaller than the amount shown in FIG.
• the plastic deformation is performed by means of a compressive stress applying means 45 such as a vise.
• the compressive force applying means 45 includes a guide 47 for regulating the deformation of the slide moving member 17 and a compressive force applied to the slide moving member 17. It has a holding jig 48 that changes the length of the slide moving member 17 in the longitudinal direction with high accuracy by applying force.
• the optical spectrum analyzer 43 when compressive stress is applied to the slide moving member 17, the optical spectrum analyzer 43 is applied to the optical spectrum analyzer 43 as shown in FIG. The center wavelength of light transmission of the arrayed waveguide grating was monitored. Then, the slide moving member 17 was plastically deformed so that the monitored light transmission center wavelength became the set wavelength.
• the inventor of the present invention outputs the light from the eighth optical output waveguide 6, which is the eighth port of the arrayed waveguide type diffraction grating.
• the light transmission center wavelength of the moving light was measured before the plastic deformation of the slide moving member 17.
• the value of the light transmission center wavelength was 1550.2 Onm.
• the slide moving member 17 is plastically deformed in the slide moving direction by the above method, and the eighth wavelength of the light transmission center wavelength of the arrayed waveguide type diffraction grating is the grid wavelength. The value was changed to 150.0.116 nm.
• the central wavelength of light transmission from one optical output waveguide 6 is a grid wavelength
• the central wavelength of light transmission from another optical output waveguide 6 can also be a dalit wavelength.
• the second embodiment can also achieve the same effects as the first embodiment.
• the present invention is not limited to the above embodiments, but can take various forms.
• the plastic deformation of the slide moving member 17 was performed by applying a tensile I force to the slide moving member 17.
• a compressive stress can be applied to the slide moving member 17.
• the light transmission center wavelength of the arrayed waveguide grating can be changed to the longer wavelength side.
• the sliding member 17 may be formed by providing a locking recess 32 of a pulling jig on the surface side. .
• plastic deformation of the slide moving member 17 can be performed by applying a tensile stress.
• the application of the tensile stress is performed by, for example, a pulling jig 33 as shown in FIG. 7D.
• the slide moving member 17 is plastically deformed in the slide moving direction, so that the center wavelength of the light transmission center wavelength of the arrayed waveguide diffraction grating is reduced. Can be corrected to the shorter wavelength side.
• the slide moving member 17 forms a dent or hole 34 in a displacement area in the slide direction (an area indicated by J in the figure). You may. Then, as shown in FIGS. 8C and 8D, the wedge member 35 serving as a fitting member having a wider diameter than the opening of the recess or hole 34 is inserted into the recess or the recess. It may be fitted in hole 34. Also in this case, by fitting the wedge member 35 into the recess or the hole 34, the length of the slide moving member 17 can be corrected from the set wavelength of the light transmission center wavelength of the arrayed waveguide type diffraction grating. Length. Then, the same effect as in the first embodiment can be obtained.
• the configuration shown in FIGS. 8C and 8D does not necessarily move the slide moving member 17 due to the deformation of the sliding member 17 due to the fitting of the wedge member 35 into the recess or the hole 34. It does not have to be plastically deformed. In other words, when the wedge member 35 is fitted into the recess or hole 34, when the wedge member 35 is removed from the recess or hole 34, the length of the slide moving member 17 becomes the original length. Returning to the so-called “Sexual Marauder”
• the arrayed waveguide type diffraction grating of the present invention is, for example, shown in FIG.
• the configuration shown in FIG. B, FIG. 9C, and FIG. 9D may be adopted.
• a screw hole 36 as a depression or hole is formed in the displacement area (the area indicated by J in the figure) of the slide moving member 17 in the slide direction, and the screw hole 36 is formed in the screw hole 36.
• Taber screw 37 as a fitting member is fitted.
• the taper screw 37 has a wide-diameter portion wider than the opening of the screw hole 36, and the diameter of the taper screw becomes smaller toward the distal end.
• the length of the slide moving member 17 is corrected from the set wavelength of the optical transmission center wavelength of the arrayed waveguide type diffraction grating by fitting the taper screw 37 into the screw hole 36.
• the same effect can be obtained by setting the length to be the same.
• the deformation of the slide moving member 17 due to the fitting of the taper screw 37 into the screw hole 36 may be in the elastic deformation range. Further, this configuration makes it very easy to finely adjust the amount of deformation of the slide moving member 17 depending on the insertion depth of the taper screw 37.
• this configuration can increase or decrease the length of the slide moving member 17 by adjusting the amount of tightening of the taper screw 37. Therefore, this configuration can be configured so that the central wavelength of light transmission can be finely adjusted to both the long wavelength side and the short wavelength side.
• the tightening amount of the tapered screw 37 is adjusted, for example, as follows. First, the slide moving member 17 in a state where the screw 37 is inserted halfway through the screw hole 36 is fixed to the arrayed waveguide type diffraction grating. Thereafter, if it is desired to shift the center wavelength of light transmission of the arrayed waveguide type diffraction grating to the shorter wavelength side, the penetration depth of the threaded screw 37 into the screw hole 36 is increased, and Increase the length of 17 To correct the light transmission center wavelength of the arrayed waveguide grating to the longer wavelength side, reduce the insertion depth of the taper screw 37 into the screw hole 36 or remove the taper screw 37. To shorten the length of the slide moving member 17.
• a compressive stress in the X direction in FIG. 5C was applied to the sliding material 17.
• the configuration of the second embodiment is changed so that the length of the slide moving member 17 in the slide moving direction becomes longer, for example, by applying a compressive stress in the Y direction in FIG. 5C. It can also be done.
• the slide moving direction of the slide moving member 17 is the X direction in FIGS. 5A and 5C.
• the deformation method of the slide moving member 17 is not particularly limited, and is appropriately set. That is, the important point is that the slide moving member 17 is deformed in the slide moving direction, and the length of the slide moving member 17 is set to the light transmission center wavelength of the array waveguide type diffraction grating. This is the length that corrects the deviation from the wavelength.
• the arrayed waveguide type diffraction grating in which the length of the slide moving member 17 is adjusted can provide the same effects as those of the above embodiments.
• the deformation of the slide moving member 17 is caused by the light transmission center of the arrayed waveguide type diffraction grating. It is recommended to monitor while monitoring the wavelength. In other words, it is preferable to move the separated slab waveguide along the separation surface of the separated slab waveguide by the slide moving member 17 so that the monitored light transmission center wavelength becomes the set wavelength.
• the first slab waveguide 3 is separated, but the second slab waveguide 5 may be separated. That is, since the arrayed waveguide type diffraction grating is formed by utilizing the reciprocity of light, even if the second slab waveguide 5 is separated, the same effect as in the above embodiment can be obtained. Can be
• the sliding movable material 17 is plastically deformed. After that, at least one side of the separated separated slab waveguide was
• the slide is moved along the surface in a direction to reduce the temperature-dependent excitation of the respective light transmission center wavelengths.
• the second slab 3 ⁇ 4 wave path 5 The configuration in which the sides are separated can also obtain the same effects as those of the above-described embodiments and examples, and can eliminate the temperature-dependent fluctuation of the respective light transmission center wavelengths.
• the separation plane (intersection separation plane) 8 of the first slab waveguide 3 and the second slab waveguide 5 is not necessarily a plane substantially parallel to the X-axis as in the above embodiments.
• the cross separation plane 8 may be a plane oblique to the X axis.
• the cross separation surface 8 may be any surface that intersects the path of light passing through the slab waveguide to be separated and is a surface that separates the slab waveguide.
• the slide moving member 17 that slides the separation slab waveguide 3 a side along the separation surface 8 is provided with the first and second waveguide forming regions 10. a, 10b.
• the arrangement form of the sliding movable city material 17 is not particularly limited, and is appropriately set.
• a base of an arrayed waveguide type diffraction grating is provided, the second waveguide forming region 10b is fixed to the base, and the first waveguide forming region 10a is slidable with respect to the base. I do. Then, one end of the slide moving member 17 is used as a base, and the other end is fixed to the first waveguide formation region 10a.
• the first waveguide formation region 10 a may be slid along the separation surface 8 depending on the temperature.
• the slide moving member 17 is formed of metal copper, but the slide moving member 17 may be formed of a metal other than copper. Further, the slide moving material 17 may be formed of a material other than a metal having a larger thermal expansion coefficient than the tomb plate and the waveguide forming region of the arrayed waveguide type diffraction grating.
• metal can be easily processed such as plastic deformation, if the metal is used as the slide moving member 17, there is an advantage that the array waveguide type diffraction grating can be easily manufactured. Further, the slide moving member 17 does not have to be configured to move the separated slab waveguide by utilizing expansion and contraction due to heat as described above.
• the separation slab waveguide is moved, for example, by mechanically moving one end of the slide moving member 17 to the separation slab waveguide and moving the separation slab waveguide to the other end of the slide moving member 17. It can be performed even if at least one of the moving means and the electric moving means is provided.
• the arrayed waveguide type diffraction grating according to the present invention can set the light transmission center wavelength substantially at the set wavelength, for example, at any temperature within the operating temperature range. Suitable for light transmission devices.

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• 2001
  • 2001-10-11 CN CN01802959A patent/CN1392961A/zh active Pending
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  • 2001-10-11 EP EP01976666A patent/EP1260837A4/en not_active Withdrawn
  • 2001-10-11 WO PCT/JP2001/008944 patent/WO2002033462A1/ja not_active Application Discontinuation
  • 2001-10-11 KR KR1020027007549A patent/KR20020070459A/ko not_active Application Discontinuation
• 2002
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