| 摘要 |
PURPOSE:To improve precision of vibration detection and an answerig property, by a method wherein an object to be measured is irradiated with coherent light having a specified frequency, and a heterodyne detection is made on the reflection light and a reference light of a specified frequency. CONSTITUTION:Coherent light (angular frequency omegao) from a photo oscillator 4 is divided by an optical processor 5 such as half mirrors, and the one light of them is reflected by a reflecting mirror 6 and is also phase-modulated by means of a signal (omegar) to produce a reference light having an angular frequency omegao+omegar. The other light is reflected by an object A to be measured vibrated at DELTAomega to produce a reflecting light having an angular frequency omegao+DELTAomega. The reflecting light and reference light enter a collector 1 via an optical processor 5 to produce light having an angular frequency omegar+DELTAomega through interference, and a detector 2 performs a heterodyne detection through the working of an amplifier 7, a filter 8, and a high-grain amplifier 9 and by means of a signal having an angular frequency omegar from the oscillator 17. A signal of an angular frequency DELTAomega is displayed (13) through a filter 10, an amplifier 11, and a wave-form processor 13. This causes obtaining of a high vibration-detecting precision and an answering property. |
