| 摘要 |
PURPOSE:To enable setting of the polarization angle of extraordinary light at a large angle by providing an optical medium which changes the polarization angle of incident light by the heat generation of a heating element and forming the optical medium of SrxBa1-xNb2O6. CONSTITUTION:The optical deflecting element 10 has the planar optical medium 11 consisting of the SrxBa1-xNb2O6 which is a ferroelectric crystal having a solid soln. compsn. region and the heating element 12. The value of X is preferably set at nearly a 0.25<=X<=0.5 range. The reason for setting the value of X in such range lies in that the Curie temp. of the SrxBa1-xNb2O6 when the value of x is set at about 0.25 is 200 deg.C and the Curie temp. when the value of X is set at nearly 0.5 is 130 deg.C and, therefore, the transformation from the ferroelectric crystal to an ordinary electric crystal does not arise at the ordinary environmental temp. at which the element is used (for example, the temp. at the time of heat generation of the heating element). A temp. gradient is generated in the thickness direction of the optical medium 11 by the heat generation in the heating element 12 with such constitution, by which a refractive index gradient is generated and the extraordinary ray is deflected in the a-axis direction and outputted. |
