JPH0459612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a polarization angle adjustment device that can perform simple and precise position adjustment of the angle of a polarization plane of an optical fiber.

(b) Problems with the Prior Art A conventional polarization angle adjustment device is shown in the side view in FIG. 1a and the front view in FIG. 1b. That is, a sleeve-shaped adapter 4 having a linear circular hole, a pair of cores 2 and 3 fitted and inserted on the same axis with a predetermined interval D in the circular hole of this adapter 4, and this pair. An optical fiber 1 made of one piece of quartz glass is continuously inserted into the center hole of the cores 2 and 3 and fixed to each of the cores 2 and 3, and the tip of the movable member 5 is opposite to each other on both sides. The first and second electromagnets 6 and 7 which attract and tilt the movable member 5 of the lever in the directions of arrows A and B are
They are arranged one by one at intervals.

One of the cores is a fixed core 2 fixed to the adapter 4, and the other is a movable core 2 which is rotatable relative to the adapter 4 and has a movable member 5 provided outside the adapter 4 and extending in a radial direction. Child 3.

Note that the movable member 5 is made of a magnetic material, such as iron. The first and second electromagnets 6, 7 are connected to a power supply circuit, that is, to a power supply 8, 8 via a power switch 9, 9, respectively.

With the above configuration, the switch 9 on the first electromagnet 6 side
When the is turned on and the first electromagnet 6 is energized, the movable member 5 is attracted in the direction of arrow A and is tilted around the movable core 3. As a result, an angle based on this tilt angle is given to the movable core 3. , the optical fiber 1 is twisted at the distance D in the adapter 4, so that stress is generated inside the optical fiber 1, and the stress changes the plane of polarization of the transmitted light depending on the optical rotation of the optical fiber 1. The angle is rotated in the direction of twisting the optical fiber 1. In this way, twisting an optical fiber in the circumferential direction to rotate the angle of the plane of polarization of the optical transmission wave propagating within the optical fiber depending on the optical rotation of the optical fiber is described in the literature. It is also described on pages 151 to 178 of the 1st edition of "Hikari Fiber" published by Ohmsha Co., Ltd. on April 30, 1980, by Kazuo Hotate.

The switch 9 of the power circuit of the second electromagnet 7 may be turned OFF at a desired angle while monitoring this state with a measuring device (not shown). However, if the angle exceeds the desired angle, the switch 9 of the power circuit of the second electromagnet 7 When turned on, the movable member 5 is attracted and tilted in the opposite direction of arrow B, so repeat the operation of turning off the power circuit of the second electromagnet 7 at the desired angle while monitoring with the measuring instrument, and then Controls the wave angle.

The above-mentioned conventional device has a complicated device configuration and uses many electromagnets, which requires a large amount of power.The movable material uses a material with relatively high magnetic resistance, such as iron, so the movable material generates heat. Curve. Further, there were other problems such as difficulty in finely adjusting the angle.

(c) Purpose of the Invention In view of the above conventional problems, the present invention provides an optical fiber polarization angle adjustment device that has a simple structure, is small, consumes little power, and can finely adjust the rotation angle of the polarization plane. The purpose is to provide.

(d) Configuration of the Invention In order to achieve the above object, the configuration of the present invention includes an adapter having a linear circular hole, and an adapter that is fitted and inserted on the same axis with a predetermined facing interval in the circular hole of the adapter. a pair of cores, one optical fiber continuously inserted into the center hole of the pair of cores and fixed to each core; one of the cores is fixed to an adapter and the other is fixed to the adapter. The core is rotatable with respect to the adapter, and has a movable member provided extending in a radial direction outside the adapter, and a movable member facing the tip of the movable member so as to rotate the core. The current control means comprises electromagnetic means for attracting, spring means for biasing the movable member in a direction opposite to the attracting direction of the electromagnetic means, and current control means for adjusting the current supplied to the electromagnetic means. The optical fiber is twisted in accordance with the rotation angle of the movable core with respect to the fixed optical fiber in conjunction with the tilting angle of the movable member based on the attraction force of the electromagnet by the control amount. The purpose is to enable the polarization angle to be adjusted to a desired position.

(e) Embodiments of the Invention Hereinafter, embodiments of the optical fiber polarization angle adjusting device of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a side cross-sectional view of a first embodiment of the apparatus of the present invention, and a front view shows its basic configuration in b.
Note that parts equivalent to those in FIG. 1 are given the same reference numerals. An adapter 4 having a linear circular hole, a pair of cores 2 and 3 fitted and inserted on the same axis with a predetermined opposing interval D in the circular hole of this adapter 4, and this pair of cores. An optical fiber 1 made of quartz glass is continuously inserted into the center holes 2 and 3 and fixed to each core 2 and 3, and a coiled spring (compression spring) is attached to one side of the tip of the movable member 5. Electromagnets 10 are arranged to face each other via a coil spring 11.

One of the cores is a fixed core 2 fixed to the adapter 4, and the other core is rotatable about an axis relative to the adapter 4 and includes a movable member 5 provided extending in the radial direction outside the adapter 4. This is a movable core 3.

Note that the movable member 5 is made of a magnetic material, such as iron. The electromagnet 10 is connected to a power supply circuit consisting of a DC power supply 12 via a switch 13 and a current controller 14. The relationship between the electromagnet 10 and the coil spring 11 with respect to the movable member 5 is such that the electromagnet 10 attracts and tilts the movable member 5 in the direction of arrow C, and the coil spring 11 presses and tilts it in the opposite direction of arrow D. Of course, these tilting movements are performed around the movable core 3.

With the above configuration, turn on switch 13 of the power supply circuit.
When the electromagnet 10 is excited, the movable member 5 is attracted to the electromagnet 10 against the repulsive force of the coiled spring 11.
It is tilted in the direction of arrow C. As a result of the angle given to the movable core 3 based on this tilting angle, the optical fiber 1 is twisted at the distance D within the adapter 4, thereby generating stress inside the optical fiber 1.
Due to this internal stress, the angle of the plane of polarization of the transmitted light is rotated in the direction in which the optical fiber is twisted, depending on the optical rotation of the optical fiber 1.

The excitation attraction force of the electromagnet 10 can be controlled by adjusting the current controller 14 to change the amount of current supplied. Therefore, while monitoring the amount of rotation angle of the plane of polarization using a measuring device (not shown), the amount of current may be increased so as to reach a desired angle. However, if the desired rotation angle is exceeded, the attractive force of the electromagnet 10 is reduced by adjusting the amount of current to decrease, and the repulsive force of the coiled spring 11 is accordingly balanced with the attractive force. Since the movable member 5 is pushed back into position, the desired angular position can be achieved. This can be done arbitrarily by monitoring the measuring device. The operation of the current controller 14 may be stopped after the angular position is determined, or the movable member 5 may be fixed at that position by a fixing means (not shown) and the switch 13 may be turned off.

FIG. 3 shows the principal structure of a second embodiment of the present invention in a front view, and the same parts as in FIG. 2 are given the same reference numerals. In this embodiment, electromagnets 15 are arranged at predetermined intervals on one side of the movable member 5, a power supply circuit consisting of a switch 13, a current controller 14, and a DC power source 12 is connected to the electromagnets 15, and A coiled spring (in this case, a tension coil spring) 11
is engaged. One end of the coiled spring 11 is engaged with the movable member 5 and the other end is engaged with a fixed part, thereby biasing the movable member 5 in the direction of arrow D in FIG. It is configured to attract Therefore, the current regulator 14
By tilting the movable member 5 to a desired angle, the optical fiber 1 can be twisted and adjusted.

FIG. 4 is a side view illustrating a third embodiment of the device of the present invention, in which the same parts as in FIG. 2 are given the same reference numerals. The adapter 4 is further fitted on the left side of the fixed core 2 in the illustrated direction of FIG. A movable member 5 extending from the child 3 has a spring means and an electromagnet 10 arranged at the tip.

As described above, by providing two rotation angle adjustment parts in series, the
The angle can be adjusted twice as much. In this case, the movable members 5, 5 need to be able to tilt in opposite directions. Of course, it is also possible to combine it with the one shown in FIG.

In the above embodiments, the spring means is a coiled spring, but the spring means is not limited to this, and any arbitrary spring such as a torsion spring or a leaf spring can be used.

(f) Effects of the Invention As detailed above, the optical fiber polarization angle adjustment device according to the present invention has a simple configuration, is compact, consumes little power, and has no risk of generating heat, so it is easy to avoid deformation of the movable member. In addition to eliminating obstacles to
The practical effects are remarkable, such as being able to finely adjust the twisting rotation angle.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional device, b is a front view, Fig. 2 is a side view of a first embodiment of the inventive device, b is a front view, and Fig. 3 is a front view of the inventive device. FIG. 4 is a front view of the main parts of the second embodiment of the present invention, and FIG. 4 is a front view of the main parts of the third embodiment of the apparatus of the present invention. Symbols in each figure: 1 is an optical fiber, 2 is a fixed core, 3 is a movable core, 4 is an adapter, 5 is a movable member,
6, 7, 10, 15 are electromagnets, 8 is a power supply, 9, 1
3 is a switch, 11 is a coiled spring, 12 is a DC power supply, and 14 is a current controller.

Claims (1)

[Claims] 1. An adapter having a linear circular hole, a pair of cores that are fitted and inserted on the same axis with a predetermined opposing interval in the circular hole of the adapter, and a core that is continuous to the center hole of the pair of cores. One optical fiber is inserted through the cores and fixed to each core, one of the cores is fixed to the adapter, and the other core is rotatable relative to the adapter and radially outside the adapter. A movable member extending from the movable member, an electromagnetic means that faces the tip of the movable member and attracts the movable member so as to rotate the core, and a direction in which the electromagnetic means attracts the movable member. It consists of a spring means that biases in the opposite direction, and a current control means that adjusts the current supplied to the electromagnet means, and the tilting angle of the movable member is determined based on the attractive force of the electromagnet by the control amount of the current control means. It is characterized in that the angle of the polarization plane of the optical fiber can be adjusted to a desired position by twisting the optical fiber in accordance with the rotation angle of the core on the movable side with respect to the optical fiber on the fixed side. Optical fiber polarization angle adjustment device.