JP5183575B2 - Method and apparatus for adjusting optical path length using magnetic field in hollow optical waveguide - Google Patents

Description

  The present invention enables continuous optical path length adjustment in an optical communication mechanism, makes it possible to ensure a sufficiently long optical path length adjustment width as compared with conventional optical path length adjustment methods, and inserts a reflector. The present invention relates to an optical path length adjusting method and apparatus using a magnetic field in a hollow optical waveguide that does not require an insertion / extraction mechanism.

  As a general optical path length adjusting method, as shown in FIG. 8, a light source 601 and a light receiving unit 602, and a reflecting unit 603 and a reflecting unit 603 in which two reflecting materials (mirrors and the like) are set at an angle of 90 degrees. Is configured to be movable in the optical axis direction. The light source 601, the light receiving unit 602, and the concave surface of the reflecting unit 603 are set to face each other, and the optical path length is adjusted by moving the stage 604 in the optical axis direction. There is a way to implement.

  Further, as described in Patent Document 1, a method has been proposed in which two reflecting materials are arranged in parallel and the number of reflections is adjusted by rotating the entire reflecting material to adjust the optical path length.

  In either method, continuous optical path length adjustment is feasible, but if the optical path length adjustment width is to be increased, the optical path length adjustment system itself must be increased. There was a problem that it could not be set large.

JP 2000-193415 A

  The present invention solves the above-described problem, and the optical path length is set to a desired value by moving the reflecting material inserted in the hollow portion of the optical waveguide in the longitudinal direction of the optical waveguide by the magnetic field generating means. By using a magnetic field in a hollow optical waveguide, a large optical path length adjustment width can be realized even with a small device without using a long reflecting material, and continuous optical path length adjustment can be performed. It is an object of the present invention to provide an optical path length adjusting method and apparatus.

  The optical path length adjusting method using a magnetic field in a hollow optical waveguide according to the present invention is such that a magnetic reflecting material is inserted in a hollow portion of a hollow optical waveguide so as to be movable in the longitudinal direction, and a magnetic field is applied to the outside of the optical waveguide. Magnetic field generating means capable of generating is installed, and the reflector is attracted to the magnetic field generated by the magnetic field generating means, thereby determining the position in the optical waveguide, and from one end of the optical waveguide to the optical waveguide The length of the optical path from the one end of the optical waveguide to the outside of the optical waveguide is reflected by the light incident on the reflecting material, and the length of the optical waveguide is reflected by the magnetic field generating means. It is characterized by adjusting by moving in the direction.

  In the optical path length adjusting method using a magnetic field in the hollow optical waveguide, the present invention is characterized in that the reflecting material can be adjusted to a position in accordance with a designated optical path length.

  An optical path length adjusting device using a magnetic field in a hollow optical waveguide according to the present invention includes a hollow optical waveguide, a magnetic reflective material inserted in a hollow portion of the optical waveguide in a longitudinal direction, Magnetic field generating means installed outside the optical waveguide and capable of generating a magnetic field that determines a position in the optical waveguide by attracting the reflecting material, and enters the optical waveguide from one end of the optical waveguide The reflected light is reflected on the end face of the reflecting material, and the optical path length from the one end of the optical waveguide to the outside of the optical waveguide is moved in the longitudinal direction of the optical waveguide by the magnetic field generating means. Means for adjusting by doing so.

  According to the present invention, in the optical path length adjusting device using a magnetic field in the hollow optical waveguide, an optical fiber having a hollow core structure is used as the optical waveguide.

  In the optical path length adjusting apparatus using a magnetic field in the hollow optical waveguide, the present invention is characterized in that a minute magnetic material or a magnetic fluid is used as the reflecting material.

  In the optical path length adjusting device using a magnetic field in the hollow optical waveguide, the present invention uses a reflective material in which the entire reflective material or a reflective material component is covered with a metal thin film having a high light reflectance as the reflective material. It is what.

  In the optical path length adjusting device using a magnetic field in the hollow optical waveguide, the position of the magnetic field generating means is fixed, and the optical waveguide itself is longitudinally moved using the winding mechanism of the optical waveguide. The distance between the one end of the optical waveguide and the reflecting material is controllable by moving to.

  According to the present invention, in the optical path length adjusting device using a magnetic field in the hollow optical waveguide, the magnetic field generating means moves in the longitudinal direction of the optical waveguide to move the position of the reflecting material. Is.

  In the optical path length adjusting device using a magnetic field in the hollow optical waveguide, the present invention is characterized in that the magnetic field generating means can be applied with an electromagnet or a permanent magnet, and can be constituted by a plurality. Is.

  The present invention controls the position of the reflecting material in the optical waveguide having a hollow structure by a magnetic field generating means installed outside the optical waveguide, thereby allowing light incident from one end of the optical waveguide to be positioned at an arbitrary position in the optical waveguide. By making the light reflected at, continuous optical path length adjustment becomes possible. Furthermore, since the present invention can use an optical fiber having a hollow core structure as the optical waveguide, it is possible to ensure a sufficiently large optical path length adjustment width as compared with the conventional method and to adjust the adjustment width. The size of the system can be reduced as compared with the conventional method.

  Furthermore, in the present invention, it is possible to make the amount of the reflective material constant regardless of the reflection position.

1 is an explanatory diagram illustrating a configuration of an optical path length adjusting device according to a first embodiment of the present invention. It is composition explanatory drawing which shows the optical path length adjustment apparatus which concerns on the 2nd Embodiment of this invention. It is composition explanatory drawing which shows the optical path length adjustment apparatus which concerns on the 3rd Embodiment of this invention. It is composition explanatory drawing which shows the optical path length adjustment apparatus which concerns on the 4th Embodiment of this invention. The 1st example of the installation method of the magnetic field generation means which concerns on embodiment of this invention is shown, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view. The 2nd example of the installation method of the magnetic field generation means which concerns on embodiment of this invention is shown, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view. It is a longitudinal cross-sectional view which shows the 3rd example of the installation method of the magnetic field generation means which concerns on embodiment of this invention. It is structure explanatory drawing which shows the conventional optical path length adjustment apparatus.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is an explanatory diagram showing a configuration of an optical path length adjusting device according to the first embodiment of the present invention. In FIG. 1, 100 is a light source, 200 is a light receiver, 300 is an optical circulator, 301 is an input port, 302 is an output port, 303 is an input / output port, and 400 is an optical waveguide. For example, an optical fiber having a hollow core structure ( For example, a photonic band gap fiber). Reference numeral 501 denotes a reflective material having magnetism, for example, a micromagnetic material or a magnetic fluid, which includes a case where the entire reflective material or a reflective material component is covered with a metal thin film having a high light reflectance. Reference numeral 502 denotes a control terminal, for example, a personal computer. Reference numeral 503 denotes a motor, and reference numeral 504 denotes magnetic field generating means capable of generating a magnetic field, for example, a permanent magnet or an electromagnet using a ferromagnetic material. Reference numeral 505 denotes a reel, 506 denotes a winding mechanism, 507 denotes a motor, 508 denotes a reel, and 509 denotes a winding mechanism.

  As shown in FIG. 1, one end of a hollow optical waveguide 400 is connected to the input / output port 303 of the optical circulator 300, the light source 100 is connected to the input port 301 of the optical circulator 300, and the output port 302 of the optical circulator 300. Is configured to connect the light receiver 200. A magnetic field generating means 504 is installed outside the optical waveguide 400, and a reflecting material 501 is inserted into the hollow portion of the optical waveguide 400 corresponding to the magnetic field generating means 504 so as to be movable in the longitudinal direction (axial direction). The motors 503 and 507 are connected to the control terminal 502.

  A winding mechanism 506 is provided between the output port 302 of the optical circulator 300 and the magnetic field generating means 504, and the winding mechanism 506 rotates the reel 505 around which the optical waveguide 400 is wound by the motor 503, whereby the optical circulator 300. The length of the optical waveguide 400 between the output port 302 and the magnetic field generating means 504 can be adjusted. A winding mechanism 509 is provided on the opposite side of the magnetic field generating means 504 from the optical circulator 300, and the winding mechanism 509 rotates the reel 508 around which the optical waveguide 400 is wound by the motor 507, thereby winding the optical waveguide 400. And send out.

  The light emitted from the light source 100 passes through the optical circulator 300, enters the optical waveguide 400 from one end of the optical waveguide 400, is reflected at the end surface of the reflecting member 501, and goes out of the optical waveguide 400 from the one end of the optical waveguide 400. The light is emitted and reaches the light receiver 200 via the optical circulator 300.

  The reflective member 501 is fixed to the position of the magnetic field generating unit 504 in the optical waveguide 400 by being attracted to the magnetic field generated by the magnetic field generating unit 504.

  In the case of FIG. 1, the position of the magnetic field generation means 504 itself is fixed, and therefore the position of the reflector 501 itself is also fixed. The distance between the input / output port 303 of the optical circulator 300 and the end face of the reflector 501, that is, the optical path length in the optical waveguide 400 is realized by the optical waveguide 400 itself moving back and forth in the longitudinal direction. Specifically, the optical waveguide 400 can be moved back and forth in its longitudinal direction by the operation of two winding mechanisms 506 and 509 installed at both ends of the optical waveguide 400 so as to sandwich the magnetic field generating means 504. It becomes.

  The operations of the motors 503 and 507 of the winding mechanisms 506 and 509 are controlled by the control terminal 502. For example, when the optical path length in the optical waveguide 400 is extended from the present time, the control terminal 502 causes the winding mechanism 506 on the optical circulator 300 side to start the winding operation and simultaneously sends it to the winding mechanism 509 on the opposite side. To start. When the movement length of the optical waveguide 400 reaches the set optical path length, the control terminal 502 stops the operations of the winding mechanisms 506 and 509.

  Further, for example, when the optical path length in the optical waveguide 400 is shortened from the present time, the control terminal 502 causes the winding mechanism 506 on the optical circulator 300 side to start the feeding operation and simultaneously winds the winding mechanism 509 on the opposite side. Start operation. When the movement length of the optical waveguide 400 reaches the set optical path length, the control terminal 502 stops the operations of the winding mechanisms 506 and 509.

  When the magnetic field generation means 504 is an electromagnet, the magnetic field generation means 504 is connected to the control terminal 502 via the switch 512, and the control terminal 502 controls the switch 512 and does not energize the magnetic field generation means 504. .

  That is, the reflecting material 501 is attracted to the magnetic field generated by the magnetic field generating means 504, thereby determining the position in the optical waveguide 400, and the light incident on the optical waveguide 400 from one end of the optical waveguide 400 is reflected in the reflecting material 501. The length of the optical path from the one end of the optical waveguide 400 until it is emitted outside the optical waveguide 400 can be adjusted by moving the reflector 501 in the longitudinal direction of the optical waveguide 400 by the magnetic field generation means 504. . Therefore, the reflector 501 can be adjusted to a position that matches the designated optical path length.

  FIG. 2 is an explanatory diagram showing a configuration of an optical path length adjusting device according to the second embodiment of the present invention. In FIG. 2, the magnetic field generating means 504 is an electromagnet, and a plurality of electromagnets are arranged and installed along the external longitudinal direction of the optical waveguide 400. Each electromagnet is connected to the switch 512, and the switch 512 is connected to the control terminal 502.

  One end of the hollow optical waveguide 400 is connected to the input / output port 303 of the optical circulator 300, the light source 100 is connected to the input port 301 of the optical circulator 300, and the light receiver 200 is connected to the output port 302 of the optical circulator 300. The light emitted from the light source 100 enters the optical waveguide 400 through the optical circulator 300, is reflected at the end face of the reflector 501, and reaches the light receiver 200 through the optical circulator 300.

  The reflector 501 is attracted and fixed to the position of the magnetic field generating means 504 in the optical waveguide 400 by the magnetic field generated by the magnetic field generating means 504.

  The distance between the input / output port 303 of the optical circulator 300 and the end face of the reflector 501, that is, the optical path length in the optical waveguide 400, is realized by the reflector 501 moving in the longitudinal direction in the optical waveguide 400. Specifically, the magnetic field generating means 504 energized by the switch 512 is switched one after another from the current position of the reflective material 501 toward the magnetic field generating means 504 at the designated position, thereby energizing the reflective material 501 with the magnetic field generating means 504. Is attracted by the generated magnetic field, and the longitudinal movement in the optical waveguide 400 becomes possible.

  The switch 512 switches the magnetic field generating means 504 to be energized based on control information from the control terminal 502.

  For example, when the optical path length in the optical waveguide 400 is extended from the present time, the control terminal 502 simultaneously energizes the switch 512 from the current position of the reflector 501 to the magnetic field generation means 504 adjacent in the optical path length extension direction. The magnetic field generation means 504 that has been previously energized is cut off, and this operation is repeated. When the moving length of the reflecting material 501 reaches the set optical path length, the control terminal 502 stops the operation of the switch 512.

  For example, when the optical path length in the optical waveguide 400 is shortened from the present time, the control terminal 502 energizes the switch 512 from the current position of the reflector 501 to the magnetic field generating means 504 adjacent in the optical path length shortening direction. At the same time, the magnetic field generation means 504 previously energized is cut off, and this operation is repeated. When the moving length of the reflecting material 501 reaches the set optical path length, the control terminal 502 stops the operation of the switch 512.

  FIG. 3 is an explanatory diagram showing a configuration of an optical path length adjusting device according to the third embodiment of the present invention. In FIG. 3, the magnetic field generating means 504 is an electromagnet, and a plurality of electromagnets are arranged on the outer periphery of a cylindrical winding frame so as to be spirally arranged at predetermined intervals. It is installed spirally along the electromagnet. Each electromagnet of the magnetic field generation means 504 is connected to the switch 512, and the switch 512 is connected to the control terminal 502.

  The structure of the optical circulator 300 after the one end of the optical waveguide 400 having the hollow structure is connected to the input / output port 303 of the optical circulator 300 is the same as that of FIG. 2, and the method of adjusting the optical path length in the optical waveguide 400 is also shown in FIG. Is the same.

  Note that the magnetic field generation means 504 and the optical waveguide 400 can be arranged in a spiral shape and in a layer shape.

  FIG. 4 is an explanatory diagram showing a configuration of an optical path length adjusting device according to the fourth embodiment of the present invention. In FIG. 4, the magnetic field generating means 504 is provided outside the optical waveguide 400 so as to be movable in the longitudinal direction, and the magnetic field generating means 504 is attached to the stage 511. The stage 511 is mounted on the shaft 510, and the shaft 510 is installed in parallel with the optical waveguide 400. One end of the shaft 510 is connected to a motor 503, and the motor 503 can rotate the shaft 510 forward and backward. A spiral groove is carved in the shaft 510, and a part of the stage 511 is engaged with the spiral groove. The stage 511 moves back and forth along the longitudinal direction of the shaft 510 in accordance with the rotational direction of the groove carved in the shaft 510. The motor 503 is connected to the control terminal 502.

  One end of the hollow optical waveguide 400 is connected to the input / output port 303 of the optical circulator 300, the light source 100 is connected to the input port 301 of the optical circulator 300, and the light receiver 200 is connected to the output port 302 of the optical circulator 300. The light emitted from the light source 100 enters the optical waveguide 400 through the optical circulator 300, is reflected at the end face of the reflector 501, and reaches the light receiver 200 through the optical circulator 300. The reflector 501 is fixed at a position in the optical waveguide 400 of the magnetic field generating means 504 by the magnetic field generated by the magnetic field generating means 504.

  In the case of FIG. 4, the distance between the input / output port 303 of the optical circulator 300 and the end face of the reflector 501, that is, the optical path length in the optical waveguide 400 is realized by the magnetic field generating means 504 moving back and forth in the longitudinal direction of the optical waveguide 400. Is done.

  The operation of the motor 503 is controlled by the control terminal 502. For example, when extending the optical path length in the optical waveguide 400 from the present time, the control terminal 502 causes the motor 503 to rotate the shaft 510 in a direction in which the stage 511 moves away from the optical circulator 300. When the movement length of the optical waveguide 400 reaches the set optical path length, the control terminal 502 stops the operation of the motor 503.

  Further, for example, when the optical path length in the optical waveguide 400 is shortened from the present time, the control terminal 502 causes the motor 503 to rotate the shaft 510 in a direction in which the stage 511 approaches the optical circulator 300. When the movement length of the optical waveguide 400 reaches the set optical path length, the control terminal 502 stops the operation of the motor 503.

  FIG. 5 shows a first example of the installation method of the magnetic field generating means according to the embodiment of the present invention. That is, this is a method of installing the magnetic field generating means 504 with respect to the optical waveguide 400. The magnetic field generating means 504 is installed so that the optical waveguide 400 is sandwiched between upper and lower positions outside the optical waveguide 400. The arrangement of the N pole and the S pole is not limited to the arrangement shown in FIG.

  FIG. 6 shows a second example of the installation method of the magnetic field generating means according to the embodiment of the present invention. In other words, the magnetic field generating means 504 is installed on the optical waveguide 400. The magnetic field generating means 504 is installed so that the optical waveguide 400 is sandwiched between the vertical position and the left and right side positions outside the optical waveguide 400, respectively. The arrangement of the N pole and the S pole is not limited to the arrangement shown in FIG.

  FIG. 7 shows a third example of the installation method of the magnetic field generating means according to the embodiment of the present invention. In other words, the magnetic field generating means 504 is installed on the optical waveguide 400. The magnetic field generating means 504 is installed so as to surround the outer periphery of the optical waveguide 400. The arrangement of the N pole and the S pole is not limited to the arrangement shown in FIG.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  DESCRIPTION OF SYMBOLS 100 ... Light source, 200 ... Light receiver, 300 ... Optical circulator, 301 ... Input port, 302 ... Output port, 303 ... Input / output port, 400 ... Optical waveguide, 501 ... Reflective material, 502 ... Control terminal, 503 ... Motor, 504 ... Magnetic field generating means, 505 ... reel, 506 ... winding mechanism, 507 ... motor, 508 ... reel, 509 ... winding mechanism, 510 ... shaft, 511 ... stage, 512 ... switch, 601 ... light source, 602 ... light receiving section, 603: Reflection unit, 604: Stage.

Claims (9)

A reflecting member having magnetism is inserted into a hollow portion of the optical waveguide having a hollow structure so as to be movable in the longitudinal direction, and a magnetic field generating means capable of generating a magnetic field is installed outside the optical waveguide. By being attracted to the magnetic field generated by the magnetic field generating means, the position in the optical waveguide is determined,
The light that has entered the optical waveguide from one end of the optical waveguide is reflected on the end surface of the reflective material, and the optical path length from the one end of the optical waveguide to the outside of the optical waveguide is determined by using the reflective material. An optical path length adjustment method using a magnetic field in a hollow optical waveguide, wherein the adjustment is performed by moving in a longitudinal direction of the optical waveguide by a magnetic field generating means.   2. The optical path length adjusting method using a magnetic field in a hollow optical waveguide according to claim 1, wherein the reflecting material can be adjusted to a position according to a specified optical path length. Method for adjusting the optical path length using a magnetic field. A hollow optical waveguide;
A reflective member having magnetism inserted into the hollow portion of the optical waveguide in a movable manner in the longitudinal direction;
A magnetic field generating means installed outside the optical waveguide and capable of generating a magnetic field for determining a position in the optical waveguide by attracting the reflecting material;
The light that has entered the optical waveguide from one end of the optical waveguide is reflected on the end surface of the reflective material, and the optical path length from the one end of the optical waveguide to the outside of the optical waveguide is determined by using the reflective material. An optical path length adjusting device using a magnetic field in a hollow optical waveguide, characterized by comprising: a magnetic field generating means for adjusting by moving in a longitudinal direction of the optical waveguide.   4. The optical path length adjusting device using a magnetic field in the hollow optical waveguide according to claim 3, wherein an optical fiber having a hollow core structure is used as the optical waveguide. .   5. The optical path length adjusting device using a magnetic field in a hollow optical waveguide according to claim 3 or 4, wherein a micro magnetic material or a magnetic fluid is used as the reflecting material. Adjustment device.   6. The optical path length adjusting device using a magnetic field in the hollow optical waveguide according to claim 3, wherein the reflecting material is a reflecting material in which the entire reflecting material or the reflecting material component is covered with a metal thin film having high light reflectivity. An optical path length adjusting device using a magnetic field in a hollow optical waveguide.   7. The optical path length adjusting device using a magnetic field in a hollow optical waveguide according to claim 3, wherein the position of the magnetic field generating means is fixed, and the optical waveguide is wound by using a winding mechanism of the optical waveguide. An optical path length adjusting device using a magnetic field in a hollow optical waveguide, wherein the distance between the one end of the optical waveguide and the reflecting material can be controlled by moving the waveguide itself in the longitudinal direction.   7. The optical path length adjusting device using a magnetic field in a hollow optical waveguide according to claim 3, wherein the magnetic field generating means moves in the longitudinal direction of the optical waveguide, thereby moving the position of the reflecting material. An optical path length adjusting device using a magnetic field in a hollow optical waveguide.   9. The optical path length adjusting device using a magnetic field in a hollow optical waveguide according to claim 3, wherein said magnetic field generating means can be applied with an electromagnet or a permanent magnet, and can be constituted by a plurality. An optical path length adjusting device using a magnetic field in a hollow optical waveguide.

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