FOURTH HARMONIC GENERATING SYSTEM USING OPTICAL CARRIER SUPPRESSED DOUBLE SIDEBAND MODULATOR

摘要

[PROBLEMS] To provide an optical modulating system for generating a signal of a frequency f₀+2f_m and a signal of a frequency f₀-2f_m and suppressing a signal of a frequency of f₀ by means of a DSB-SC modulator. [MEANS FOR SOLVING PROBLEMS] A fourth harmonic generating system for solving the above problem comprises a first DSB-SC modulator (2), a second DSB-SC modulator (3), and a signal control section (5) for controlling a modulating signal from a signal source (4) for generating modulating signals applied to the first and second DSB-SC modulators (2, 3) so that a lower sideband signal (f₀) generated by modulating the upper sideband signal of the DSB-SC modulator (2) by means of the DSB-SC modulator (3) and an upper sideband signal (f₀) generated by modulating the lower sideband signal of the DSB-SC modulator (2) by means of the DSB-SC modulator (3) cancel each other.