| 摘要 |
PURPOSE:To make it possible to measure the physical force to be measured among various physical forces without receiving the effect of the other physical forces, by directly connecting a compensation constant polarization optical fiber, which has a characteristic substantially equal to that of a sensor constant polarization optical fiber, to the sensor constant polarization optical fiber. CONSTITUTION:A polarizer 3 is arranged with respect to a compensation constant polarization optical fiber 2 so that linear polarized light is excited in a ratio of 1:1 to the X'- and Y'- directions of a constant polarization optical fiber 2. The constant polarization optical fiber 1 and the constant polarization optical fiber 2 are constituted so as to be made substantially equal in a double refraction index characteristic and same in phase difference. The main axes of both optical fibers are mutually rotated by 90 deg. to be connected so as to be crossed at right angles so that the linear polarized light propagated through the constant polarization optical fiber 2 in the X'-direction is propagated to a Y-direction in the constant polarization optical fiber 1 and that propagated through the constant polarization optical fiber 2 in the Y'-direction is propagated to an X-direction in the constant polarization optical fiber 1 to an X-direction. By this method, when the same temp. is imparted to both of the constant polarization optical fibers 1, 2, the phase difference generated between the polarizations of the sensor constant polarization optical fiber 1 in the X- and Y-directions is cancelled out by that generated between the polarizations of the compensation constant polarization optical fiber 2 in the X'- and Y'-directions. |
