| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical modulator, in which insertion loss and polarization dependence are reduced. SOLUTION: Input signal light is introduced via an optical multiplexer 1 and an optical isolator into an Er-doped amplifying optical fiber 3. Outgoing signal light from the amplifying optical fiber 3 passes through an optical multiplexer 4 and an optical isolator 5. The optical multiplexer 1 has one input end which is introduced with signal light and the other input, end being introduced with pumping light from a pumping laser light source 6. Similarly, the optical multiplexer 4 has one input end being introduced with signal light and the other input end being introduced with a pumping light from a pumping laser light source 7. Drive current of these pumping laser light sources 6, 7 is subjected to modulation control at a prescribed frequency by means of a modulation control oscillator 8. |
