| 摘要 |
PURPOSE:To make it possible to take a separate measurement of only the effect of material dispersion with high precision by causing two beams, amplitude-modulated by a single sine wave, to strike optical fiber simultaneously and by measuring the phase difference between modulated signals by selectively detecting those signals. CONSTITUTION:Light of wavelength lambdai from a light source and polarizing device 2, when passing through external modulator 3, is amplitude-modulated into a sine shape with a signal from electric signal generator 5 simultaneously with light of wavelength lambdao from single-wavelength light source 1. Two lights of lambdao and lambdai are mixed into one by synthesizer 4 before striking optical fiber 6. The light having propagated through optical fiber 6 is polarized by polarizer 7 so that light of lambdao will reach detector 8 and that of lambdai will reach detector 9. Electric signals obtained by detectors 8 and 9 are supplied to phase difference measurer 10 to measure their phase difference, on the basis of which the effect of material dispersion is found. |
