| 摘要 |
PURPOSE: To accurately and stably measure by controlling an electric field applied to an electrooptical element in response to the temperature of the element. CONSTITUTION: The temperatures of electrooptical elements 15a, 15b are detected by a temperature detector 20 provided at a thermal conductor 19, and the information is input to a CPU 22 via an A-D converter 21. The CPU 22 obtains a serrodyne voltage for maintaining the phase change of a light per unit time from the Pockels constants of the elements 15a, 15b for storing it and the temperature dependency of the refractive index. The CPU 22 obtains the multiple of the obtained driving voltage to the standard driving voltage, and inputs it to a multiplier 25 via an D-A converter 23. The multiplier 25 multiplies the multiple by the predetermined serrodyne waveform generated from a serrodyne waveform generator 24, and serrodyne drives the elements 15a, 15b by the voltage. Thus, the elements 15a, 15b are temperature compensated. |
