| 摘要 |
<p>A wavelength dispersion measuring method for measuring the group velocity dispersion of an optical element, e.g. an optical fiber, directly. The group velocity dispersion is measured using a light subjected simultaneously to optical frequency modulation and intensity modulation and utilizing a fact that an optical frequency modulated component appears as variation in the phase of intensity modulated component. Dispersion can thereby be measured with high accuracy with no effect of drift in the group delay time caused by variation of external environment. Accuracy and dynamic range do not deteriorate even in the vicinity of zero dispersion. Since the waveform of a frequency modulated signal can be made asymmetric, the code of a wavelength dispersion value can be reproduced. Wavelength dispersion can be subjected to in-service-monitoring using a digital data signal as the intensity modulated signal.</p> |
