| 摘要 |
<p>PROBLEM TO BE SOLVED: To output a converted light of the same wavelength as a signal light. SOLUTION: Pumping light 16 and a signal light 18 are multiplexed by a WDM coupler 10 and entered into a waveguide 24 of a wavelength conversion element 12. Then, difference-frequency is generated by a pseudo phase matching, and the converted light 20 is outgone together with the pumping light and the signal light from the wavelength conversion element. The converted light is polarized in the direction of TM-polarization orthogonal to the polarization direction of the signal light when the polarization direction of the pumping light is matched with TE-polarization direction. A polarizer 22 is adjusted so that the light ray matched with the TM-polarization direction among light rays outgoing from the wavelength conversion element can be transmitted when the polarization direction of the signal light is matched with TE-polarization direction. Thus the converted light is selectively transmitted.</p> |
