JP2012181470A - Array waveguide diffraction grating type optical multiplexer/demultiplexer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized array waveguide diffraction grating type optical multiplexer/demultiplexer which allows MUX and DEMUX modules to be disposed in one package and allows an input/output fiber array to be connected to one end surface thereof.SOLUTION: A plurality of waveguides 5a are formed in an end part of a waveguide chip 15. The waveguides 5a are connected to an array waveguide 9 comprising a plurality of channel waveguides having different lengths and bending in the same direction, via a slab waveguide 7. The array waveguide 9 is connected to waveguides 5b via a slab waveguide 8. That is, the waveguides 5b are provided opposite to the waveguides 5a. The waveguides 5b provided opposite to the waveguides 15a in the waveguide chip 15 are connected to an inverting waveguide 11a formed on an inverting waveguide chip 11. The inverting waveguide 11a is approximately U-shaped so that an optical signal inputted from one end part can be outputted in a direction opposite to an input direction.

Description

  The present invention relates to a compact arrayed waveguide diffraction grating type optical multiplexer / demultiplexer that can combine and demultiplex a plurality of light beams having different wavelengths in one package.

  Conventionally, as an optical device of an arrayed waveguide grating type (AWG), a MUX module that multiplexes light of a plurality of wavelengths and a DEMUX module that demultiplexes light of a plurality of wavelengths, respectively. Such multiplexing and demultiplexing modules are individually installed and used by users.

  On the other hand, when such multiplexing and demultiplexing modules are individually installed, there is a problem that costs for two devices are generated and installation space is required. Thus, a multiplexer / demultiplexer that can perform multiplexing and demultiplexing with a single device has been proposed (for example, Patent Document 1).

JP 2008-242257 A

  In recent years, such an AWG package has been made into MSA (Multi-source agreement). Therefore, it is necessary to arrange a conventional multiplexing / demultiplexing device in a size standardized by MSA. In addition, if the light input / output surface is formed at one end of the package, it becomes easy to install the AWG package in the device. Therefore, it is desirable to form the light input / output surface at one end of the package. Yes.

  On the other hand, in the conventional multiplexer / demultiplexer as described above, since a multi-fiber array is connected to both ends thereof, it is necessary to form an optical input / output surface at one end of the package. It is necessary to bend and invert the optical fiber tape constituting the fiber array. However, it is difficult to reverse a multi-fiber optical fiber tape within a standardized package due to the rigidity of the optical fiber tape and the allowable curvature radius of the optical fiber itself.

  The present invention has been made in view of such a problem, and the MUX and DEMUX modules can be arranged in one package, and the input / output surface of light can be formed at one end of the package. An object of the present invention is to provide a small arrayed waveguide grating type optical multiplexer / demultiplexer.

  In order to achieve the above-mentioned object, the present invention is connected to a plurality of first waveguides, a first slab waveguide connected to the first waveguide, and the first slab waveguide. An arrayed waveguide composed of a plurality of channel waveguides bent in the same direction with different lengths, a second slab waveguide connected to the arrayed waveguide, and connected to the second slab waveguide A plurality of second waveguides, an inverting waveguide connected to the second waveguide, and a waveguide chip on which at least the first waveguide to the second waveguide are formed. The connection direction of the first waveguide to the connection portion opposite to the side connected to the first slab waveguide is opposite to the connection direction of the inverted waveguide to the second waveguide. The connection direction at the side connection part is formed in the same direction. Is an array waveguide diffraction grating multiplexer-demultiplexer according to symptoms.

  The waveguide chip is divided in the first slab waveguide or the second slab waveguide, and the waveguide chip divided according to temperature is moved relative to each other, and the light transmission center wavelength of the arrayed waveguide grating It is desirable to provide a compensation member that can compensate for the temperature dependent shift of the.

  The inversion waveguide is preferably a planar lightwave circuit, and a joint surface at a connection portion of the first waveguide opposite to the side connected to the first slab waveguide, and the second waveguide. A joint surface where the waveguide and the inversion waveguide are joined to each other and a joint surface of the connection portion of the inversion waveguide opposite to the side connected to the second waveguide are formed substantially in parallel. Each bonding surface may be formed obliquely with respect to a direction perpendicular to the surface of the waveguide chip.

  In this case, a first fiber array is joined to the first waveguide, and a second fiber array is joined to the inversion waveguide, and the end face of the first fiber array and the second fiber are joined. The end surface of the array may be formed obliquely so as to correspond to the joint surface formed obliquely.

  In a connection part opposite to the side connected to the first slab waveguide of the first waveguide and a connection part opposite to the side connected to the second waveguide of the inversion waveguide In at least one of the first waveguide and the inversion waveguide, the width of the waveguide may be increased.

  The inversion waveguide is formed by bending an optical fiber tape in which a plurality of single optical fibers are integrated, and each single optical fiber constituting the optical fiber tape is individually provided in at least a part of the bending portion. It may be divided into two parts to be unintegrated.

  According to the present invention, since the inversion waveguide is connected to the second waveguide, the waveguide can be inverted with a minimum space. Therefore, since the waveguide can be inverted even in the standardized package, the light input / output terminals can be arranged on one end face side of the package.

  Further, in one of the first slab waveguide and the second slab waveguide, the waveguide chip is divided, and a compensation member is provided so as to straddle each of the divided waveguide chips (holding members for the waveguide chip). Thus, since it is possible to compensate for the temperature-dependent shift of the light transmission center wavelength of the arrayed waveguide grating, a temperature-independent arrayed waveguide grating optical multiplexer / demultiplexer can be obtained. Even in this case, the waveguide can be inverted in the package by using the inversion waveguide.

  If a planar lightwave circuit is used as the inverting waveguide, the structure is simple. In addition, a joint surface at a connection portion of the first waveguide opposite to the side connected to the first slab waveguide, a joint surface where the second waveguide and the inversion waveguide are joined, and inversion The joint surface of the connection portion on the opposite side to the side connected to the second waveguide of the waveguide is formed substantially parallel to each other, and is formed obliquely with respect to the surface direction of the waveguide chip. In the case of irradiating, it becomes possible to irradiate ultraviolet rays deeper, and since the adhesion area increases, the respective joint portions can be more reliably joined.

  At this time, the first fiber array is joined to the first waveguide, the second fiber array is joined to the inversion waveguide, and the end face of the first fiber array and the end face of the second fiber array are obliquely connected. By forming it diagonally so as to correspond to the joint surface formed on each other, each connection can be reliably performed on the joint surface.

  In addition, in the connection part opposite to the side connected to the first slab waveguide of the first waveguide and the connection part opposite to the side connected to the second waveguide of the inversion waveguide, If the width of at least one of the first waveguide and the inversion waveguide is increased, mode field matching with the fiber array can be obtained.

  Also, the inversion waveguide is formed by bending an optical fiber tape in which a plurality of single-core optical fibers are integrated, and each single-core optical fiber constituting the optical fiber tape is divided into at least a part of the bending portion. By releasing the integration, the second fiber array and the inversion waveguide can be formed integrally.

  According to the present invention, it is possible to arrange the MUX and DEMUX modules in one package, and to form an optical input / output surface at one end of the package. A waver can be provided.

1 is a schematic diagram showing an optical multiplexer / demultiplexer 1. FIG. It is a figure which shows each joining surface, (a) is the sectional view on the AA line in the D section of FIG. 1, (b) is the sectional view on the AA line in the E section, (c) is the BB line in the F section. Sectional drawing. The schematic diagram which shows the optical multiplexer / demultiplexer 1a. The schematic diagram which shows the optical multiplexer / demultiplexer 1b. The schematic diagram which shows the optical multiplexer / demultiplexer 1c. It is a figure which shows a joint surface and is the II sectional view taken on the line H of FIG. The schematic diagram which shows the optical multiplexer / demultiplexer 1d. The schematic diagram which shows the optical multiplexer / demultiplexer 1e. The schematic diagram which shows the optical multiplexer / demultiplexer 1g. The schematic diagram which shows the optical multiplexer / demultiplexer 1f.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an arrayed waveguide diffraction grating type optical multiplexer / demultiplexer 1. The optical demultiplexer 1 mainly includes waveguides 5a and 5b, slab waveguides 7 and 8, an arrayed waveguide 9, an inverting waveguide 11a, and the like.

  The waveguides 5a and 5b, the slab waveguides 7 and 8, the arrayed waveguide 9 and the inversion waveguide 11a are planes formed of a quartz or polymer material on a Si substrate or a quartz substrate using a known method. It is a lightwave circuit. A waveguide chip 15 having the waveguides 5a and 5b, the slab waveguides 7 and 8, and the arrayed waveguide 9 formed on the substrate, and an inverted waveguide chip 11 having the inverted waveguide 11a formed on the substrate. Call. Further, a Peltier 16 that is a temperature adjusting member is provided below a portion of the waveguide chip 15 corresponding to the arrayed waveguide 9 to keep the arrayed waveguide 9 at a constant temperature.

  A plurality of waveguides 5 a that are first waveguides are formed at the end of the waveguide chip 15. The waveguide 5a is connected to an arrayed waveguide 9 composed of a plurality of channel waveguides bent in the same direction with different lengths via a slab waveguide 7 which is a first slab waveguide. The arrayed waveguide 9 is connected to a plurality of second waveguides 5b through a slab waveguide 8 that is a second slab waveguide. That is, the waveguide 5b is provided toward the opposite side to the waveguide 5a. The waveguides 5a and 5b are each a waveguide group for inputting and outputting light.

  It is desirable that the waveguide chip 15 has a shape that follows at least the bent shape of the arrayed waveguide 9. That is, it is desirable that the waveguide chip 15 also has a bent shape. As described above, the waveguide chip 15 having a shape corresponding to the arrayed waveguide 9 can increase the number of chips taken from one wafer. However, the waveguide chip 15 is not limited to this shape.

  The waveguide 5 b provided on the opposite side of the waveguide chip 15 from the waveguide 5 a is connected to the inversion waveguide 11 a formed on the inversion waveguide chip 11. That is, the waveguide chip 15 is connected to the inversion waveguide chip 11. The inverting waveguide 11a has a substantially U-shape that can output an optical signal input from one end portion in the reverse direction toward the input direction. That is, the direction of the optical axis of the inverting waveguide 11a at the end of the waveguide 5b (for example, the input direction of the optical signal) and the direction of the optical axis at the other end (for example, the output direction of the optical signal) are inverted by 180 °. It becomes.

  A fiber array 13a that is a first fiber array is connected to the waveguide 5a. A fiber array 13b, which is a second fiber array, is connected to the end of the inversion waveguide 11a opposite to the connection with the waveguide 5b. That is, the fiber arrays 13a and 13b are formed in the same direction. The length of the inversion waveguide 11a (inversion waveguide chip 11) is set so that the fiber array 13b and the waveguide chip 15 do not interfere with each other.

  Glasses 17a and 17b are provided on the surfaces near the connection end portions of the waveguide 5a and the inversion waveguide 11a and the fiber arrays 13a and 13b. By providing the glasses 17a and 17b on the respective waveguide chips, the height (thickness) of the fiber arrays 13a and 13b connected to the waveguide 5a and the inversion waveguide 11a can be made substantially the same. Details of each joint will be described later.

  Each of the fiber arrays 13a and 13b has an optical fiber tape in which a plurality of input / output optical fibers are arranged in parallel and integrated in a tape shape. For example, when an optical signal obtained by multiplexing a plurality of optical signals having different wavelengths is input to one optical fiber of the optical fiber tape, the optical signal is input to the slab waveguide 7 through the waveguide 5a. The optical signal input to the slab waveguide 7 spreads by diffraction in the slab waveguide 7 and enters the arrayed waveguide 9. Since the waveguides of the arrayed waveguide 9 are different in length, a phase difference depending on the wavelength is generated on the output side (slab waveguide 8 side) of the arrayed waveguide 9. In the slab waveguide 8, light can be demultiplexed by being coupled to the corresponding waveguide 5 b with light of each wavelength satisfying the same phase condition due to multiple interference.

  The demultiplexed optical signal is coupled to the corresponding inversion waveguide 11a, the direction of the optical signal is inverted by the inversion waveguide 11a, and is coupled to the fiber array 13b. Therefore, the multiplexed optical signal input from the fiber array 13a can be demultiplexed and sent to the fiber array 13b.

  Conversely, when a plurality of optical signals having different wavelengths are input to the plurality of optical fibers of the fiber array 13a, they are input to the slab waveguide 7 via the waveguide 5a and enter the arrayed waveguide 9. On the output side of the arrayed waveguide 9 (the slab waveguide 8 side), a phase difference depending on the wavelength is generated, so that it can be coupled to, for example, one optical fiber of the corresponding waveguide 5b.

  If an optical signal is input from the fiber array 13b side, multiplexing / demultiplexing can be similarly performed on the fiber array 13a side.

  Next, the details of the joint portion of each configuration will be described. 2 is an enlarged cross-sectional view of each joint, FIG. 2 (a) is a cross-sectional view taken along the line AA in the D part of FIG. 1, and FIG. 2 (b) is a cross-sectional view taken along the AA line in the E part of FIG. FIG. 2 and FIG. 2C are cross-sectional views taken along the line BB in the F part of FIG.

  As shown in FIG. 2A, the waveguide chip 15 includes a substrate 6b, a lower cladding layer 12a, a waveguide 5a, and an upper cladding layer 14a from the bottom. As described above, the waveguide chip 15 is formed on the waveguide chip 15. Is provided with a glass 17a.

  On the other hand, the optical fiber array 13a includes an optical fiber tape 10a that accommodates a plurality of optical fibers and a fiber fixing portion that fixes each optical fiber 10, and the fiber fixing portion has a V-shaped cross section on the surface thereof. It consists of a substrate 6a in which V-shaped grooves are formed in parallel, and an upper lid 4a located on the substrate 6a. And the said optical fiber 10 is accommodated in the V-shaped groove | channel of the board | substrate 6a, and the board | substrate 6a and the upper cover 4a are adhere | attached and fixed with the adhesive agent in this state. The substrate 6a and the upper lid 4a can be formed of Si, glass, resin, or the like. Further, the shape of the groove for accommodating the optical fiber 10 is not limited to the V-shaped cross section, and may be a round hole, a square groove, or the like.

  The joint surface 21a between the fiber array 13a, the waveguide chip 15 and the glass 17a is formed obliquely at a predetermined angle with respect to a direction (vertical direction in the drawing) perpendicular to the surface of the waveguide chip 15. As described above, since the glass 17a is provided on the waveguide 5a in the vicinity of the bonding surface 21a, the thickness with the fiber array 13a can be matched. That is, it is possible to perform bonding with the same thickness in a state where the optical axes of the waveguide 5a and the fiber core 19a of the optical fiber 10 are aligned.

  For the bonding surface 21a, an ultraviolet curing / thermosetting adhesive that is not shown can be used. For example, when an adhesive is provided on the bonding surface 21a and ultraviolet rays are irradiated from above and below (G direction in the figure), the glass 17a transmits light. For this reason, by forming the joint surface 21a between the fiber array 13a and the waveguide chip 15 diagonally, it is possible to irradiate ultraviolet rays deeper and to cure the adhesive reliably.

  When the substrate 6b of the waveguide chip 15 is formed of Si, the Si substrate does not transmit light, so that a portion that does not sufficiently transmit ultraviolet rays is generated. However, even in this case, bonding is performed due to the effect of the thermosetting adhesive. The surface 21a can be adhered. Even in this case, since the bonding surface 21a is inclined, the bonding area can be increased, and bonding can be performed reliably. The above effect can be obtained if the angle of the bonding surface is slightly inclined with respect to the surface of the chip. However, in consideration of manufacturability and light loss, the angle is about 5 ° to 10 °. It is desirable that Further, the direction in which the joint surface is inclined may be opposite to that shown in the figure.

  As shown in FIG. 2B, the bonding surface 21b between the waveguide chip 15 and the inversion waveguide chip 11 is also perpendicular to the surface of the waveguide chip 15 (upper and lower in the figure), like the bonding surface 21a. It is formed obliquely at a predetermined angle with respect to (direction). Here, the angles of the joining surfaces of the joining surface 21a and the joining surface 21b are substantially the same. Therefore, the joining surfaces 21a and 21b are formed substantially in parallel. The joining method is the same as the method described above.

  Further, as shown in FIG. 2C, the joint surface 21c between the inverted waveguide chip 11 and the glass 17b and the fiber array 13b is also perpendicular to the surface of the waveguide chip 15 (see FIG. 2). It is formed obliquely at a predetermined angle with respect to the (medium up and down direction). Here, the angles of the joining surfaces of the joining surface 21a and the joining surface 21c are substantially the same. Therefore, the joining surfaces 21a, 21b, and 21c are formed substantially in parallel. That is, the joint surface side ends of the fiber arrays 13a and 13b with the waveguide chip 15 and the inversion waveguide chip 11 have inclined shapes in the same direction. Therefore, it is not necessary to change the shape of the fiber array connected to the waveguide chip 15 and the shape of the fiber array connected to the inversion waveguide chip 11, and the same one can be used.

  In addition, although illustration is abbreviate | omitted, the edge part (joint surface side edge part with the fiber array 13a) of the waveguide 5a is formed so that the diameter of a waveguide may be expanded a little toward an edge part. Similarly, the end of the inversion waveguide 11a (the end on the side of the joint surface with the fiber array 13b) is also formed with the width of the waveguide slightly increased toward the end. By appropriately setting the width of the waveguide, the waveguide 5a and the inversion waveguide 11a also have a function of mode field matching with each optical fiber (single mode fiber) of the fiber array.

  As described above, according to the present embodiment, an extremely compact arrayed waveguide diffraction grating type optical multiplexer / demultiplexer can be obtained. In particular, since the inversion waveguide 11a is formed in the inversion waveguide chip 11, it is not necessary to bend and invert the optical fiber tape or the like in the package, and a large bending radius due to the rigidity of the optical fiber tape is unnecessary.

  Also, the input / output fiber array can be formed in the same direction of the package, and the light input / output surface can be formed at one end of the package.

  In addition, since the bonding surfaces 21a, 21b, and 21c are formed obliquely with respect to the surface direction of the chip, the depth of ultraviolet irradiation can be increased, and the bonding area can be increased. More reliable joining can be obtained.

  Next, a second embodiment will be described. FIG. 3 is a schematic diagram illustrating an optical multiplexer / demultiplexer 1a according to the second embodiment. Note that in the following embodiments, the same reference numerals as those in FIG. 1 are given to configurations having the same functions as those of the optical multiplexer / demultiplexer 1, and duplicate descriptions are omitted.

  The optical multiplexer / demultiplexer 1a has substantially the same configuration as the optical multiplexer / demultiplexer 1, except that the waveguide chips 15a and 15b are fixed on the glass plate 3, the slab waveguide is divided, and a compensation member The difference is that 23 is provided and the Peltier 16 is not provided. The slab waveguide and the waveguide chip are divided into slab waveguides 7a and 7b and waveguide chips 15a and 15b. The division positions of the waveguide chips 15a and 15b substantially coincide with the division positions of the slab waveguides 17a and 17b. The glass plate is also divided into glass plates 3a and 3b corresponding to the division of the waveguide chips 15a and 15b.

  The compensation member 23 is a metal plate-like member, and is joined across the glass plates 3a and 3b. Although not shown in the drawings, convex portions are provided in the thickness direction at both ends of the compensation plate 23, and the compensation plate 23 is fixed to the glass plates 3a and 3b with an adhesive at the convex portions. Is done. In addition, as the compensation member 23, the thing made from copper or pure aluminum (JIS A1050) can be used, for example.

  The longitudinal direction of the compensation member 23 is arranged so as to be parallel to the dividing surface of the slab waveguides 7a and 7b (waveguide chips 15a and 15b). The length of the compensation member 23 (the length of the free expansion / contraction part excluding the adhesive part) is calculated from the circuit parameters of the arrayed waveguide diffraction grating.

  Next, the function of the compensation member 23 will be described. When the environmental temperature of the optical multiplexer / demultiplexer 1a changes, the condensing position by the slab waveguide 7 (7a, 7b) changes. On the other hand, when the compensation member 23 expands and contracts due to a temperature change, the glass plates 3 a and 3 b relatively move in the longitudinal direction of the compensation member 23. Therefore, the waveguide chips 15a and 15b and the slab waveguides 7a and 7b relatively move along their dividing surfaces. That is, if the material and length of the compensation member are set so that the amount of displacement corresponds to the change in the condensing position due to the temperature change, the change in the condensing position of the slab waveguide 7 due to the temperature can be corrected.

  Therefore, as described above, it is possible to reliably multiplex optical signals having a plurality of wavelengths input from the respective directions, and to reliably demultiplex the multiplexed optical signals into optical signals of the respective wavelengths. can do. That is, a temperature-independent optical multiplexer / demultiplexer can be obtained.

  According to the second embodiment, the same effect as the optical multiplexer / demultiplexer 1 can be obtained. Further, even a temperature-independent optical multiplexer / demultiplexer provided with the compensation member 23 can achieve downsizing. Even if the compensation member 23 (dividing surface) is formed between the waveguides 5a and 5b, it is possible to reliably invert the waveguide and provide an input / output fiber array on the same end surface side of the package. is there.

  Next, a third embodiment will be described. FIG. 4 is a diagram showing the optical multiplexer / demultiplexer 1b. In the following embodiment, an example in which the compensation member 23 is provided is shown, but a configuration similar to that of the optical multiplexer / demultiplexer 1 may be employed. The optical multiplexer / demultiplexer 1b is substantially the same as the optical multiplexer / demultiplexer 1a, but the connection direction of the inverting waveguide chip 11 is different. That is, in the optical multiplexer / demultiplexer 1 (1a), the inverting waveguide 11a is formed from the connection portion with the waveguide 5b toward the bending direction of the arrayed waveguide 9, and is connected to the inverting waveguide 11a. Are arranged above the arrayed waveguide 9 (in the drawing).

  On the other hand, in the optical multiplexer / demultiplexer 1b, the inverting waveguide 11a is formed in the direction opposite to the bending direction of the arrayed waveguide 9 from the connection portion with the waveguide 5b, and is connected to the inverting waveguide 11a. The fiber array 13b is disposed below the arrayed waveguide 9. In this case, the length of the inversion waveguide 11a (inversion waveguide chip 11) is set so that the fiber array 13b does not interfere with the glass plates 3a, 3b (including the moving region due to temperature change) or the waveguide chip 15. Should be set.

  According to the third embodiment, the same effect as the optical multiplexer / demultiplexer 1 can be obtained. In addition, by setting the direction of forming the inversion waveguide 11a to be opposite to the bending direction of the arrayed waveguide 9, the inversion waveguide chip 11 can be shortened depending on the layout of the glass plate, the waveguide chip, or the like. .

  Next, a fourth embodiment will be described. FIG. 5 is a diagram illustrating the optical multiplexer / demultiplexer 1c. The optical multiplexer / demultiplexer 1c is substantially the same as the optical multiplexer / demultiplexer 1a, but the connection form of the inverting waveguide chip 11 is different. That is, in the optical multiplexer / demultiplexer 1c, the inverting waveguide chip 11a and the waveguide chip 15 are connected upside down.

  FIG. 6 is a cross-sectional view taken along the line II in the H portion of FIG. 5 and shows details of the connecting portion. On the upper surface of the waveguide chip 15, a glass plate 17 c that is transparent to the ultraviolet light bonded and fixed is provided. The glass plate 17 c is provided so that the end surface thereof coincides with the end surface of the waveguide chip 15.

  In addition, a glass plate 17d that is transparent to ultraviolet light bonded and fixed is provided on the upper surface of the inversion waveguide chip 11a. With the inverted waveguide chip 11a upside down with respect to the waveguide chip 15, the end surface of the glass plate 17c on the waveguide chip 15 and the end surface of the glass plate 17d on the inverted waveguide chip 11a are UV-cured. By bonding with an adhesive, ultraviolet rays are transmitted through the entire bonding surface, and the chips are bonded more firmly. The inversion waveguide 11a may be formed in the bending direction of the arrayed waveguide 9 as shown in the figure, or may be formed toward the lower side of the arrayed waveguide 9 as shown in FIG. Also good.

  According to the fourth embodiment, the same effect as the optical multiplexer / demultiplexer 1 can be obtained. Moreover, since ultraviolet rays can be transmitted through all the regions in the thickness direction at the junction, an ultraviolet curable resin can be used effectively, and the waveguide chips can be reliably joined together.

  Next, a fifth embodiment will be described. FIG. 7 is a diagram illustrating the optical multiplexer / demultiplexer 1d. The optical multiplexer / demultiplexer 1d is substantially the same as the optical multiplexer / demultiplexer 1a, but the position where the inverting waveguide chip 11 is arranged is different. That is, in the optical multiplexer / demultiplexer 1d, the inverting waveguide 11a and the waveguide 5a are connected.

  That is, the inversion waveguide 11a may be connected to the divided waveguide 5a on the slab waveguide side. The inversion waveguide 11a may be formed in the bending direction of the arrayed waveguide 9 as shown in the figure, or may be formed toward the lower side of the arrayed waveguide 9 as shown in FIG. Also good.

  According to the fifth embodiment, the same effect as the optical multiplexer / demultiplexer 1 can be obtained. In addition, when a temperature-independent optical multiplexer / demultiplexer is used, the layout flexibility of the inverting waveguide is high.

  Next, a sixth embodiment will be described. FIG. 8 is a diagram illustrating the optical multiplexer / demultiplexer 1e. The optical multiplexer / demultiplexer 1e is substantially the same as the optical multiplexer / demultiplexer 1a, but is different in that the inverting waveguide chip 11 and the waveguide chip 15b are composed of one chip. That is, in the optical multiplexer / demultiplexer 1e, the inversion waveguide 11a, the waveguide 5b, and the like are formed on the same substrate.

  According to the sixth embodiment, the same effect as the optical multiplexer / demultiplexer 1 can be obtained. Further, it is not necessary to join the waveguide chips.

  Next, a seventh embodiment will be described. FIG. 9 is a diagram illustrating the optical multiplexer / demultiplexer 1g. The optical multiplexer / demultiplexer 1g is substantially the same as the optical multiplexer / demultiplexer 1 except that the optical multiplexer / demultiplexer 1g does not have the Peltier 16 and is provided with a groove 18 in the slab waveguide 7 so as to intersect the light traveling direction. . The groove 18 is filled with a material having a refractive index temperature coefficient with a sign different from that of the effective refractive index of the waveguide (hereinafter referred to as “temperature compensation material”). The groove 18 may be provided not on the slab waveguide 7 but on the arrayed waveguide 9.

  The size of the groove 18 is calculated from the refractive index temperature coefficient of the temperature compensation material and the circuit parameters of the arrayed waveguide diffraction grating. Thus, by providing the waveguide 18 with the groove 18 filled with the temperature compensation material, a temperature-independent optical multiplexer / demultiplexer can be obtained.

  According to the seventh embodiment, the same effect as the optical multiplexer / demultiplexer 1 can be obtained.

  Next, an eighth embodiment will be described. FIG. 10 is a diagram illustrating the optical multiplexer / demultiplexer 1f. The optical multiplexer / demultiplexer 1f is substantially the same as the optical multiplexer / demultiplexer 1a, but differs in that the inverting waveguide 11b is not a planar lightwave circuit formed on the inverting waveguide chip 11, but is formed by an optical fiber tape. .

  The optical fiber tape (inverted waveguide 11b) is formed by arranging a plurality of optical fibers in parallel and integrating them in a tape shape. An optical fiber tape integrated in a tape shape has high rigidity, and is difficult to bend as it is, and requires a very large bending radius.

  On the other hand, in the optical multiplexer / demultiplexer 1f, in the fiber array 13b connected to the waveguide 5b, the portion corresponding to the inversion waveguide 11b, that is, at least part of the curved portion is untaped, and the optical fiber tape Are separated and separated by a single-core optical fiber. Therefore, the bending radius of each optical fiber can be reduced with respect to the state of the optical fiber tape, and the entire optical fiber can be inverted (bent at 180 °) with a small bending radius.

  That is, the optical fiber tape can be taken out in the same direction of the package by inverting the optical fiber tape in a small package. Note that the inversion waveguide 11b may be formed in the bending direction of the arrayed waveguide 9 as shown in the figure, or formed toward the lower side of the arrayed waveguide 9 as shown in FIG. Also good.

  According to the eighth embodiment, the same effect as that of the optical multiplexer / demultiplexer 1 can be obtained. In addition, it is possible to provide an optical multiplexer / demultiplexer that does not require the inverting waveguide 11 and is low in cost.

In a temperature-independent device as shown in FIGS. 3 to 8, a part of the substrate (chip) is divided and a compensation member for compensating the temperature is formed on the substrate, so that the fiber array is inverted. It is difficult to take up the space to be managed.
Moreover, in such a temperature-independent device, since it is necessary to fill the package with resin, high airtightness in the package is required. In order to easily obtain high airtightness at the exit of the optical fiber, it is preferable to form a light input / output surface at one end of the package. Therefore, the present invention can be particularly suitably used in such a temperature-independent device.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1, 1a, 1b, 1c, 1d, 1e, 1f .... Optical multiplexer / demultiplexer 3a, 3b ......... Glass plate 4a, 4b ......... Top cover 5a, 5b ......... Waveguide 6a, 6b, 6c, 6d ......... Substrate 7, 7a, 7b ......... Slab waveguide 8 ......... Slab waveguide 9 ......... Array waveguide 10 ......... Optical fiber 10a, 10b ......... Optical fiber tape 11, 11a ......... Inverted waveguide chips 11a, 11b ......... Inverted waveguides 12a, 12b, 12c ......... Lower cladding layers 13a, 13b ......... Fiber arrays 14a, 14b, 14c ......... Lower cladding layers 15, 15a, 15b ... ... Waveguide chip 16 ......... Peltier 17a, 17b ......... Glass 18 ......... Grooves 19a, 19b ......... Fiber cores 21a, 21b, 21c, 21d ......... Junction surface 23 ......... Compensation member

Claims (7)

A plurality of first waveguides;
A first slab waveguide connected to the first waveguide;
An arrayed waveguide comprising a plurality of channel waveguides connected to the first slab waveguide and bent in the same direction with different lengths;
A second slab waveguide connected to the arrayed waveguide;
A plurality of second waveguides connected to the second slab waveguide;
An inverting waveguide connected to the second waveguide;
A waveguide chip formed from at least the first waveguide to the second waveguide;
Comprising
The connection direction of the first waveguide in the connection portion opposite to the side connected to the first slab waveguide and the side of the inversion waveguide opposite to the side connected to the second waveguide. An arrayed waveguide diffraction grating type optical multiplexer / demultiplexer, wherein the connecting direction in the connecting portion is formed in the same direction. The waveguide chip is divided in the first slab waveguide or the second slab waveguide;
The compensation member capable of relatively moving the waveguide chip divided by temperature and compensating for the temperature-dependent shift of the light transmission center wavelength of the arrayed waveguide grating is provided. Array waveguide diffraction grating type optical multiplexer / demultiplexer.   3. The arrayed waveguide grating optical multiplexer / demultiplexer according to claim 1, wherein the inversion waveguide is a planar lightwave circuit. A joint surface at a connection portion of the first waveguide opposite to the side connected to the first slab waveguide;
A bonding surface on which the second waveguide and the inversion waveguide are bonded;
The joint surface at the connection portion opposite to the side connected to the second waveguide of the inversion waveguide is formed substantially parallel to each other,
4. The arrayed waveguide grating optical multiplexer / demultiplexer according to claim 3, wherein each joint surface is formed obliquely with respect to a direction perpendicular to the surface of the waveguide chip.   A first fiber array is joined to the first waveguide, and a second fiber array is joined to the inversion waveguide, and an end face of the first fiber array and an end face of the second fiber array 5. The arrayed waveguide diffraction grating type optical multiplexer / demultiplexer according to claim 4, wherein the optical waveguide is formed obliquely so as to correspond to the joint surface formed obliquely.   In a connection part opposite to the side connected to the first slab waveguide of the first waveguide and a connection part opposite to the side connected to the second waveguide of the inversion waveguide 6. The arrayed waveguide diffraction grating according to claim 3, wherein at least one of the first waveguide and the inversion waveguide has a width of the waveguide expanded. Type optical multiplexer / demultiplexer.   The inversion waveguide is formed by bending an optical fiber tape in which a plurality of single optical fibers are integrated, and each single optical fiber constituting the optical fiber tape is individually provided in at least a part of the bending portion. 3. The arrayed waveguide grating optical multiplexer / demultiplexer according to claim 1 or 2, wherein the integration is broken by dividing into two.

Images