| 摘要 |
PURPOSE:To enable manufacturing of a high-efficiency temperature detector, by a method wherein an acoustic resonator is filled with a material which increases a pressure through the absorption of a photo wave, and a modulation photo wave is introduced thereinto to enable it to detect a modulation frequency in which an acoustic level is maximized. CONSTITUTION:A photo wave, which is modulated by a frequency being variable-controlled, is supplied to an acoustic resonator which is provided with a material, absorbing a photo wave to increase a pressure, at its inside and resonates with an acoustic wave of a given frequency. A photo fiber acoustic wave detector detects the acoustic level of said resonator at the current time to find a modulation in which said level is maximized, and the temperature of the resonator is found from the value. For example, a modulation photo wave is fed to an acoustic resonator 1, which is filled with CH4 gas, by a modulator 6 and a wavelength sweep laser generator 5 through a photo fiber 2. An acoustic level at the current time is measured by an optical system consisting of a photo fiber phone 14 and a photo detector 8, and a modulation frequency, in which said level is maximized, is further found by a look-in amplifier 9 to perform a measurement. |
