JP4865585B2 - Optical array - Google Patents

Description

  The present invention relates to an optical array in which rod lenses are precisely arranged.

2. Description of the Related Art Conventionally, an optical array in which a plurality of rod lenses are arranged in a horizontal direction has been used, for example, for connecting optical arrays (see, for example, Patent Document 1). FIG. 3 shows a front view of a conventional optical array. The optical array 90 is formed on two substrates 91 such that eight rod lens grooves 92 face each other. The optical array 90 is formed on two substrates 91 such that two optical fiber grooves 95 face each other. The two substrates 91 are bonded such that the rod lens 93 is sandwiched between the surfaces of the rod lens grooves 92 and the single mode optical fiber 96 is sandwiched between the surfaces of the respective optical fiber grooves 95. The optical array 90 propagates the monitoring light to the single mode optical fiber 96 and propagates the signal light to the rod lens 93 at the time of positioning.
JP-A-5-264841

  However, in the optical array 90, it is necessary to provide the rod lens groove 92 and the optical fiber groove 95 on each of the two substrates 91, and there is a problem that the manufacturing process becomes complicated.

  A typical outer diameter of the rod lens 93 is, for example, 1 mm. The standard outer diameter of the single mode optical fiber 96 is, for example, 125 μm. In this case, since the outer diameters of the rod lens 93 and the single mode optical fiber 96 are different, it is necessary to provide the rod lens groove 92 and the optical fiber groove 95 having different shapes and sizes in the substrate 91. There is a problem that the manufacturing process becomes complicated.

  An object of the present invention is to provide an optical array that has high positioning accuracy and is easy to manufacture.

  In order to solve the above problems, the optical array according to the present invention is characterized in that the shape and size of the rod lens mounting groove and the rod-shaped body mounting groove are substantially equal.

  Specifically, the optical array according to the present invention includes a rod lens mounting groove for mounting a rod lens and a flat plate provided with a rod-shaped body mounting groove for mounting a rod-shaped body on one surface; A cylindrical rod lens disposed so as to contact the surface of the groove, a cylindrical rod-shaped body disposed so as to contact the surface of the groove for mounting the rod-shaped body, and the rod lens and the rod-shaped body disposed on the flat plate. A flat plate-shaped pressing plate to be pressed, wherein the flat plate has a shape and size substantially equal to the rod lens mounting groove and the rod-shaped body mounting groove, A single-mode optical waveguide core having an outer diameter substantially equal to that of the rod lens and having a higher refractive index than the surroundings is provided at the center in the major axis direction.

  In the optical array, the rod lens and the rod-shaped body have substantially the same outer diameter. Therefore, the rod lens mounting groove and the rod-shaped body mounting groove having substantially the same shape and size as the flat plate can be provided. Easy to manufacture. Further, the optical array described above can use a plate without a groove as the pressing plate, and is easy to manufacture. Further, the optical array can be positioned with high accuracy by using the single mode optical waveguide core of the rod-shaped body.

  In the optical array according to the present invention, the pressing plate is provided with a rod lens mounting groove so as to be opposed to the rod lens mounting groove of the flat plate, and is opposed to the rod-shaped body mounting groove of the flat plate. A rod-shaped body mounting groove is provided, the rod lens is disposed so as to be in contact with the surface of the rod lens mounting groove of the pressing plate, and the rod-shaped body is used for mounting the rod-shaped body of the pressing plate. It is preferable that it is disposed so as to contact the surface of the groove.

  The optical array can fix the relative position of the flat plate and the pressing plate via the rod lens and the rod-shaped body.

  The present invention can provide an optical array that has high positioning accuracy and is easy to manufacture.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment. Moreover, the same code | symbol was attached | subjected to the same member and the same site | part.

(First embodiment)
FIG. 1 is a front view of the optical array according to the first embodiment viewed from the connection surface side. The optical array 100 includes a rod lens mounting groove 114 on which a rod lens 120 is mounted and a rod 110 mounting groove 116 on which a rod-shaped body 140 is mounted on one surface 112, and a rod lens mounting groove 114. The cylindrical rod lens 120 disposed so as to be in contact with the surface, the cylindrical rod body 140 disposed so as to be in contact with the surface of the rod-shaped body mounting groove 116, and the rod lens 120 and the rod-shaped body 140 are formed on the flat plate 110. An optical array 100 including a flat pressing plate 130 to be pressed, and the flat plate 110 has a rod lens mounting groove 114 and a rod-shaped body mounting groove 116 having substantially the same shape and size, and the rod-shaped body 140. Has a single mode optical waveguide core 142 having an outer diameter substantially equal to that of the rod lens 120 and having a higher refractive index than the surroundings at the center in the long axis direction. FIG. 1 shows a clad 144 formed around the single mode optical waveguide core 142.

  Examples of the flat plate 110 include a silicon substrate, a quartz glass substrate, and a Pyrex (registered trademark) substrate. Further, the flat plate 110 needs one or more flat surfaces 112. In the flat plate 110, for example, eight rod lens mounting grooves 114 are provided on the flat surface 112. The number of rod lens mounting grooves 114 is not limited to eight, and may be one or more.

  In the flat plate 110, for example, two rod-shaped body mounting grooves 116 are provided on the flat surface 112 on both sides of the eight rod lens mounting grooves 114. The number of rod-like body mounting grooves 116 is not limited to two, and may be one or more. Further, the rod-shaped body mounting groove 116 is not limited to the both sides of the rod lens mounting groove 114, and may be provided at an arbitrary position on the flat surface 112.

  As shown in FIG. 1, the rod lens mounting groove 114 and the rod-shaped body mounting groove 116 have, for example, a V-shaped cross section. Further, the rod lens mounting groove 114 and the rod-shaped body mounting groove 116 may be U-shaped, inverted trapezoidal or rectangular in cross section (not shown). The rod lens mounting groove 114 and the rod-shaped body mounting groove 116 are provided by grinding, for example, if the flat plate 110 is a quartz glass substrate or a Pyrex (registered trademark) substrate, and etching if the flat plate 110 is a silicon substrate. Can be provided. It is preferable that all the rod lens mounting grooves 114 and the rod-shaped body mounting grooves 116 are provided substantially in parallel so that their intervals are substantially constant. As described above, the optical array 100 can be provided with the rod lens mounting groove 114 and the rod-shaped body mounting groove 116 having substantially the same shape and size, and is easy to manufacture.

  When the rod lens mounting groove 114 and the rod-shaped body mounting groove 116 have different shapes and sizes as in the conventional optical array by etching, the etching conditions such as resist material, etching solution, etching temperature and etching time are mounted on the rod lens. It is necessary to change between the groove 114 and the rod mounting groove 116. In this case, it is necessary to obtain optimum etching conditions for each of the rod lens mounting groove 114 and the rod-shaped body mounting groove 116, which makes manufacture difficult. Further, when the rod lens mounting groove 114 and the rod-shaped body mounting groove 116 are etched separately, the flat plate 110 may be damaged by a plurality of etchings. On the other hand, the optical array 100 does not have the above disadvantages.

  Further, when the rod lens mounting groove 114 and the rod-shaped body mounting groove 116 have different shapes and sizes by grinding as in the conventional optical array, the accuracy of the rod lens mounting groove 114 and the rod-shaped body mounting groove 116 is ensured. Becomes difficult. On the other hand, the optical array 100 does not have the above disadvantages.

  The rod-shaped body 140 includes, for example, a clad 144 having an outer diameter substantially equal to that of the rod lens 120 and a single mode optical waveguide core 142 having a higher refractive index than the surrounding clad 144. Moreover, the outer diameter of the rod-shaped body 140 is 1 mm, for example.

  The rod-shaped body 140 can be manufactured by combining, for example, an MCVD method or a VAD method and a drawing method.

  The manufacture of the rod-shaped body 140 by the MCVD method is as follows, for example. The quartz glass tube is heated from the outside, and a gas containing the raw material of the clad 144 and a gas containing the raw material of the single mode optical waveguide core 142 are sequentially injected and laminated on the inner side of the quartz glass tube. Thereafter, the quartz glass tube starts to collapse in the major axis direction due to the surface tension, so that the rod-shaped body 140 is manufactured by further heating to a desired outer diameter. As a raw material of the single mode optical waveguide core 142 and the clad 144, for example, an additive such as germanium, phosphorus, boron, or fluorine is added to a main raw material such as silicon dioxide, silicon tetrachloride, or germanium tetrachloride. There is something that has changed. Here, the refractive index can be increased by adding germanium or phosphorus to the main material, and the refractive index can be decreased by adding boron or fluorine to the main material. In the MCVD method, it is easy to control the concentration distribution of the additive, and the rod-shaped body 140 having a desired refractive index distribution can be easily manufactured.

  The manufacture of the rod-shaped body 140 by the VAD method is as follows, for example. The rod-shaped body 140 is manufactured by burning the material of the clad 144 and the material of the single-mode optical waveguide core 142 in a gas mixed with hydrogen and oxygen and laminating them on the rod-shaped base material. As raw materials for the single mode optical waveguide core 142 and the clad 144, main raw materials and additives similar to those in the MCVD method can be used. The VAD method can use a large base material, and can keep the manufacturing cost low.

  The manufacture of the rod-shaped body 140 by the drawing method is as follows, for example. The manufactured preform (base material) is vertically arranged inside the electric furnace. When the lower end portion of the preform is heated to about 2000 ° C. or more, the preform is dissolved, and the preform hangs down into a linear shape due to its own weight. The rod-shaped body 140 can be manufactured by pulling the portion of the preform that hangs down in a linear shape to have a desired outer diameter.

  Further, as the rod-like body 140, for example, a single mode optical fiber may be inserted in the center of a cylindrical glass, zirconia or plastic resin rod having an outer diameter substantially equal to that of the rod lens 120 (not shown). Alternatively, the rod-shaped body 140 may be manufactured by inserting a single mode optical fiber into a glass rod having an inner diameter larger than the outer diameter of the single mode optical fiber and collapsing.

  Examples of the rod lens 120 include a gradient index rod lens and a convex rod lens. The outer diameter of the rod lens 120 is 1 mm, for example.

  Examples of the pressing plate 130 include a silicon substrate, a quartz glass substrate, and a Pyrex (registered trademark) substrate. Further, the pressing plate 130 is bonded to the flat plate 110, the rod lens 120, and the rod-shaped body 140 using an adhesive such as an ultraviolet adhesive (UV adhesive) that is cured by irradiating ultraviolet rays or a silicon resin adhesive. Is done. As described above, the optical array 100 can be easily manufactured because a plate without grooves can be used as the pressing plate 130.

  In the optical array according to the first embodiment, it is preferable that the connection surface of the optical array 100 is inclined by a predetermined angle from a surface perpendicular to the optical axes of the rod lens 120 and the rod-shaped body 140 (not shown). For example, the connection surface of the optical array 100 is inclined by 8 degrees from a surface perpendicular to the optical axes of the rod lens 120 and the rod-shaped body 140. Thereby, the optical array 100 can increase the return loss.

  Here, the connection surface is a surface on the side connected to another optical element such as a rod lens array. The end surfaces of the flat plate 110, the rod lens 120, the pressing plate 130, and the rod-shaped body 140 are preferably located on the connection surface. If the end surfaces of the flat plate 110, the rod lens 120, the pressing plate 130, and the rod-shaped body 140 are not positioned on the connection surface, the cause of the poor connection of the optical array 100 and the insertion loss of the rod lens 120 and the rod-shaped body 140 may occur. Causes to increase.

  In the optical array according to the first embodiment, it is preferable that the difference between the thermal expansion coefficients of the flat plate 110, the rod lens 120, the pressing plate 130, and the rod-shaped body 140 is small, and the flat plate 110, the rod lens 120, the pressing plate 130, and the rod-shaped member. More preferably, the thermal expansion coefficient of the body 140 is substantially equal. If the difference in coefficient of thermal expansion among the flat plate 110, the rod lens 120, the pressing plate 130, and the rod-shaped body 140 is large, a strong stress is applied to the optical array 100 as the temperature changes, and the optical array 100 is likely to be damaged. Become. Further, when stress is applied to the rod lens 120 and the rod-shaped body 140, the refractive index changes, which causes the optical characteristics of the optical array 100 to deteriorate.

  The optical array 100 can be used by connecting the connection surface to another optical element. Hereinafter, the positioning of the optical array 100 will be described using the case where the optical arrays 100 of FIG. 1 are connected to each other as an example. The two optical arrays 100 are connected so that the connecting surfaces face each other and the optical axes of the rod lens 120 and the rod-shaped body 140 coincide. When the optical arrays 100 are connected to each other, monitor light having a predetermined intensity is input to the single mode optical waveguide core 142 of the rod-shaped body 140 of one optical array 100 and the single-mode optical waveguide of the rod-shaped body 140 of the other optical array 100 is input. The intensity of the monitor light output from the wave core 142 is measured. The insertion loss of the rod-shaped body 140 can be obtained from the difference between the intensity of the input monitor light and the intensity of the output monitor light. It is preferable to adjust the position of the optical array 100 so that the insertion loss of the rod-shaped body 140 is reduced. As described above, the optical array 100 can be positioned with high accuracy by using the single mode optical waveguide core 142 of the rod-shaped body 140. Here, if the rod-shaped body 140 is disposed at both ends, the positioning accuracy can be further increased.

(Second Embodiment)
The difference between the optical array according to the second embodiment and the optical array according to the first embodiment will be mainly described. FIG. 2 shows a front view of the optical array according to the second embodiment viewed from the connection surface side. In the optical array 100, the pressing plate 130 is provided with a rod lens mounting groove 134 so as to face the rod lens mounting groove 114 of the flat plate 110, and has a rod shape so as to face the rod-shaped body mounting groove 116 of the flat plate 110. A body mounting groove 136 is provided, the rod lens 120 is disposed in contact with the surface of the rod lens mounting groove 134 of the pressing plate 130, and the rod-shaped body 140 is a rod-shaped body mounting groove 136 of the pressing plate 130. It is preferable to arrange | position so that the surface of this may be touched.

  The cross-sectional shape of the rod lens mounting groove 134 and the rod-shaped body mounting groove 136 is, for example, V-shaped, U-shaped (not shown), inverted trapezoidal shape (not shown), or rectangular shape (not shown). There is. The rod lens mounting groove 134 and the rod-shaped body mounting groove 136 are provided by grinding, for example, if the pressing plate 130 is a quartz glass substrate or a Pyrex (registered trademark) substrate, and the pressing plate 130 is a silicon substrate. If there is, it can be provided by etching. Since all the rod lens mounting grooves 134 and the rod-shaped body mounting grooves 136 have substantially the same shape and size, the pressing plate 130 can be easily manufactured. Further, the rod lens mounting groove 134 and the rod-shaped body mounting groove 136 are provided, for example, approximately in parallel so that the distance between them is substantially constant. The number of rod lens mounting grooves 114 and rod lens mounting grooves 134 are preferably the same, and the number of rod-shaped body mounting grooves 116 and the number of rod-shaped body mounting grooves 136 are preferably the same. The number of rod lens mounting grooves 134 is not limited to eight, and may be one or more. Furthermore, the number of rod-shaped body mounting grooves 136 is not limited to two, and may be one or more.

  Further, in the optical array 100, the bonding surface of the pressing plate 130 can be widened by providing the rod lens mounting groove 134 and the rod-shaped body mounting groove 136 on the pressing plate 130, and the pressing plate 130 bonded to the flat plate 110. Is difficult to peel off.

  The optical array 100 can fix the relative position of the flat plate 110 and the pressing plate 130 via the rod lens 120 and the rod-shaped body 140. For this reason, if a set of the same number of flat plates 110 and pressing plates 130 is prepared, the optical array 100 can be stacked to easily produce a two-dimensional optical array. Further, if the relative positions of the flat plate 110 and the pressing plate 130 of the stacked optical arrays 100 are fixed, positioning can be facilitated, and a highly accurate two-dimensional optical array can be provided.

  The optical array according to the present invention can be used as a waveguide splitter, AWG, optical switch, rod lens array, and collimator array.

It is the front view seen from the connection surface side of the optical array which concerns on 1st Embodiment. It is the front view seen from the connection surface side of the optical array which concerns on 2nd Embodiment. It is a front view of the conventional optical array.

Explanation of symbols

91 Substrate 92 Rod lens groove 95 Optical fiber groove 96 Single mode optical fiber 90, 100 Optical array 110 Flat plate 112 Surface 114, 134 Rod lens mounting groove 116, 136 Rod-shaped body mounting groove 93, 120 Rod lens 130 Pushing Plate 140 rod-like body 142 single mode optical waveguide core 144 clad

Claims (2)

A rod lens mounting groove for mounting a rod lens and a rod-shaped body mounting groove for mounting a rod-shaped body are provided on one side of a flat plate, and a cylindrical shape disposed so as to be in contact with the surface of the rod lens mounting groove An optical system comprising: a rod lens; a columnar rod-shaped body disposed so as to be in contact with the surface of the rod-shaped body mounting groove; and a flat plate-shaped pressing plate that presses the rod lens and the rod-shaped body against the flat plate. An array,
The flat plate has substantially the same shape and size as the rod lens mounting groove and the rod-shaped body mounting groove,
An optical array, wherein the rod-shaped body has a single mode optical waveguide core having an outer diameter substantially equal to that of the rod lens and having a higher refractive index than the surroundings at the center in the major axis direction. The pressing plate is provided with a rod lens mounting groove so as to face the rod lens mounting groove of the flat plate, and a rod-shaped body mounting groove is provided so as to face the rod-shaped body mounting groove of the flat plate. And
The rod lens is disposed so as to contact the surface of the rod lens mounting groove of the pressing plate,
The optical array according to claim 1, wherein the rod-shaped body is disposed so as to be in contact with a surface of the rod-shaped body mounting groove of the pressing plate.

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