| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrooptical light modulator capable of operating at a lower voltage than before.SOLUTION: An electrooptical crystal according to the present invention is a KTN single crystal, which is 4 mm in length and 2 mm in thickness. The thickness direction is a direction <100> of the crystal. As its phase transition temperature Tc in an electric field zero is 35°C, this KTN single crystal is used by retaining it at 40.5°C with a temperature adjuster or the like, which is a temperature little higher than that and near the critical end point. The dielectric constant in an electric field zero at this temperature is 15,000. The electrode, for both, is formed by evaporating Pt and Au in order. The KTN single crystal is temperature-controlled at 40.5°C, and further, while a 620 V bias application voltage, which is also near the critical end point, is being applied between the two electrodes, a laser beam in wavelength of 633 nm is injected in it. It was confirmed that, when an AC control voltage is superposed on the bias voltage, the intensity of light emitted from an analyzer is modulated. |
