APPARATUS FOR MEASURING WAVELENGTH DISPERSION OF OPTICAL COMPONENT BY USING MODE-LOCKED RING LASER

摘要

PROBLEM TO BE SOLVED: To measure the wavelength dispersion of an optical component, to be measured, whose absolute value of a dispersion value is small with high accuracy by a method wherein the wavelength dispersion characteristic of the optical component is found on the basis of a known wavelength and on the basis of a corresponding detected frequency. ;SOLUTION: A light amplifier 11 which amplifiers the amplitude of input light, a wavelength-variable filter 12 which is oscillated selectively by two kinds of known wavelengths and an intensity modulator 13 which changes the intensity of transmitted light are used, and a mode-locked ring laser ring in which light orbits is formed. An optical component 2 to be measured is inserted into the ring, a part of the light in the ring is introduced, a mode-locked oscillator is detected by a photodetector 3, and an output signal is observed by an oscilloscope 15. In addition, on the basis of the modulation frequency of the intensity modulator 13, a fundamental frequency corresponding to a certain optical wavelength, i.e., a mode-locked oscillation pulse-repetition frequency, is detected by a signal generator 14, and the wavelength-variable filter 12 changes the wavelength of light which orbits inside the ring. At this time, when a wavelength is dispersed in the optical component 2 to be measured, wavelength light is changed, the fundamental wavelength is changed, the changed fundamental wavelength is measured, and the wavelength dispersion characteristic of the optical component 2 to be measured is computed and found.;COPYRIGHT: (C)1998,JPO