| 摘要 |
<p>PURPOSE: To ensure high accuracy of measurement through operating point control by an arrangement wherein one or more element of a piezoelectric modulator is made of a material having same geometrical profile and crystal arrangement as a sensor element. CONSTITUTION: A piezoelectric modulator 5 comprises a plurality of modulator elements including at least one element made of a material having same geometrical profile and crystal arrangement as a sensor element 3. Total optical phase shift due to variation in the length of a sensor fiber 2 is compensated by a modulator 5 having same geometrical profile as the sensor element 3. The modulator elements and the sensor element 3 are arranged to have substantially identical temperature and thereby the temperature error is substantially eliminated from the control signal for the modulator elements. The signal and the temperature drift are compensated individually. A PI controller 9a and an amplifier 10 are provided for temperature drift compensation.</p> |
