| 摘要 |
<p>PURPOSE:To obtain a small-sized sensor which has no natural double refraction and has a good temperature characteristic, by providing a 1/4 wavelength plate and a prism in one end of a Pockels element and using one polarizing prism as a polarizer and an analyzer. CONSTITUTION:The light from a light source 1 is led to an optical sensor 3 through an optical fiber 2 and is converted to a parallel beam by a microlens 4 and is converted to a linearly polarized wave by a polarizing beam splitter 7b. When a voltage to be measured is applied across transparent electrodes 6a and 6b, the incident light generates a phase difference in accordance with the magnitude of the applied voltage in the direction of principal oscillation by a Pockels element 5 and is changed from the linear polarized light to an elliptically polarized light. This light passes through a 1/4 wavelength plate 8b and is reflected by a prism 11 and is incident to the Pockels element 5 again and passes through a 1/4 wavelength plate 8a, the polarizing beam splitter 7b, the microlens 4, and the optical fiber 2 and is converted photoelectrically by a photodetector 10 to measure the voltage to be measured. Thus, the light passes through the Pockels element forward and backward to eliminate the natural double refraction.</p> |
