Standard high-frequency signal generator and the standard high-frequency signal generating method

摘要

PROBLEM TO BE SOLVED: To set the line width of a beat signal to be a few tens of kHz or less which is stable and to make it possible to set the frequency thereof as desired, in a single laser light source.;SOLUTION: CW light from a CW laser light source 16 is inputted into an electroabsorption modulator 17 to which a sine wave electrical signal is applied. A modulation sideband which consists of line spectra at separations equal to the modulation frequency is generated from the electroabsorption modulator 17. An optical fiber 19 for higher-order soliton compression broadens the optical spectrum width, and increases the number of line spectra. A tunable wavelength filtering device which consists of optical fiber gratings 20-1 and 20-2 and optical circulators 21-1 and 21-2 chooses two of the line spectra, which are combined by an optical coupler 11-2 with their beat signal being heterodyne wave detected by a photo-detector 12.;COPYRIGHT: (C)2004,JPO