JP3293910B2 - Sensing fiber structure for optical fiber gyro - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensing fiber structure for an optical fiber gyro, and more particularly, to a novel optical fiber gyro which is inexpensive and has low drift by applying pressure from outside to suppress fluctuations in the polarization plane. Regarding improvements.

[0002]

2. Description of the Related Art The structure shown in FIG. 4 is generally employed as a sensing fiber structure for an optical fiber gyro which has been conventionally used. That is, FIG.
Is a bobbin having a ring shape, and a sensing fiber 2 is wound around the outer periphery of the bobbin 1.

[0003]

The conventional sensing fiber structure for an optical fiber gyro has the following problems because it has been configured as described above. In other words, in order to reduce the price of the optical fiber gyro itself, instead of using an expensive polarization-maintaining fiber, a low-priced single-mode fiber that is generally used for communication and the like is used. The gyro output drifted due to the change (rotation) of the polarization plane.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In particular, it is an object of the present invention to provide an inexpensive, low-drift optical fiber gyro by applying pressure from the outside to suppress fluctuations in the polarization plane. Aim.

[0005]

A sensing fiber structure for an optical fiber gyro according to the present invention is a sensing fiber structure for an optical fiber gyro having a sensing fiber wound around an annular bobbin for detecting an angular velocity input in the optical fiber gyro. , with the addition of pressure from the outside to the sensing fiber by belt member provided on the outer periphery of the sensing fiber, the band portion
The material is in the form of a thin ohmic plate, the ends of which are
And the sensor is tightened by the fastening screw.
Freely adjust the pressure from outside the single fiber
This is a configuration that can be performed .

[0006]

[0007]

In the sensing fiber structure for an optical fiber gyro according to the present invention, pressure is applied from outside the sensing fiber. The output plane can be reduced without the polarization plane becoming unstable due to the influence of the magnetic field, the temperature, and the like.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a sensing fiber structure for an optical fiber gyro according to the present invention will be described below in detail with reference to the drawings. The same or equivalent parts as those in the conventional example will be described with the same reference numerals. 1 to 3 show a sensing fiber structure for an optical fiber gyro according to the present invention. FIG. 1 is a perspective view, FIG. 2 is a perspective view of a band member, and FIG. 3 is a schematic configuration diagram showing an optical fiber gyro. .

In FIG. 1, reference numeral 1 denotes a ring-shaped bobbin. A sensing fiber 2 composed of a single mode fiber is wound around the outer periphery of the ring-shaped bobbin 1 as in the conventional structure. A belt member 3 having the configuration shown in FIG.

The band member 3 is formed in a thin ohmic shape, and its both ends 3a and 3b are connected by connecting screws 4, and the pressure from the outside of the sensing fiber 2 can be freely adjusted by the tightening of the connecting screws 4. It is configured to be able to.

[0011] Sensing fiber 2 having the above configuration
Is applied to an optical fiber gyro 10 shown in FIG. 3, and the sensing fiber 2 is connected to a second coupler 14 from a first coupler 12 and a polarizer 13 via a phase modulator 11. Light source 15 and detector 1
6 are connected.

In the above-described configuration, by applying pressure to the outer periphery of the sensing fiber 2 via the band member 3, the polarization plane is preserved by the same operation as that of the polarization plane preserving fiber, and the bidirectional light interferes. The output drift due to the rotation of the polarization plane is eliminated, and a highly accurate optical fiber gyro can be obtained.

[0013]

As described above, the sensing fiber structure for an optical fiber gyro according to the present invention has the following effects. That is, by applying pressure from the outside to the sensing fiber, the rotation of the polarization plane can be suppressed, the polarization planes of the left and right circling lights coincide, stable interference is obtained, and the drift of the output of the gyro is suppressed. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a sensing fiber structure for an optical fiber gyro according to the present invention.

FIG. 2 is a perspective view showing the band member of FIG. 1;

FIG. 3 is a configuration diagram showing an optical fiber gyro.

FIG. 4 is a perspective view showing a conventional sensing fiber structure.

[Explanation of symbols]

 Reference Signs List 1 annular bobbin 2 sensing fiber 3 band member 10 optical fiber gyro

Claims (1)

(57) [Claims] 1. A sensing fiber structure for an optical fiber gyro having a sensing fiber (2) wound around an annular bobbin (1) for detecting an angular velocity input in the optical fiber gyro (10), wherein the sensing fiber
A pressure is applied to the sensing fiber (2) from the outside by a band member (3) provided on the outer periphery of (2), and the band is applied to the sensing fiber (2).
The member (3) is in the form of a thin ohm, and its ends (3a, 3b) are
Combined by a set screw (4) and a fastener for said set screw (4)
Pressure from the outside of the sensing fiber (2)
The sensing fiber structure for an optical fiber gyro, characterized in that it is possible to freely adjust the distance.