| 摘要 |
PURPOSE:To obtain an angular velocity meter which is not affected by variation in wavelength characteristics owing to an external factor by reading variation in the wavelength of a light source, etc., with signals obtained from the 1st and the 2nd interference means and holding it constant or making corrections. CONSTITUTION:An electric signal from a photoelectric converting circuit 21 is detected synchronously at adjacent odd- or even-numbered and mutually different frequencies of a fundamental frequency supplied to the 1st phase modulator 22 to correct the light wavelength variation of the light source with the mutual difference between the adjacent odd or even degrees of a Bessel function of the 1st kind in interference light. Further, light beams passed through the 2nd and the 3rd optical paths 33 and 34 from the 2nd light source 32 are made to interfere with each other and conversion 42 into an electric signal is performed. Then, this signal is detected synchronously at adjacent mutually different odd- or even-numbered frequencies of the fundamental frequency component supplied to the 2nd phase modulator 39 and the modulator 22 is so controlled that the Bessel functions of even or odd degrees in the detection output become equal to each other, thereby making the physical operation of the modulator 22 to the 1st optical path 16 constant. |
