| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an apparatus for converting wavelengths which can realize stable wavelength conversion without depending on the polarization state of a signal light. SOLUTION: The wavelength conversion apparatus includes a multiplexer 10 which multiplexes pump light and signal light, a wavelength conversion element 1 which generates output light polarized in the x direction by converting the wavelength of a linearly polarized component in the x direction among the pump light and the signal light, an optical circulator 11 which outputs the light of the multiplexer 10 to the wavelength conversion element 1, and outputs light from the wavelength conversion element 1 to a port 11c, a reflecting mirror 20, and a Faraday rotator 22 which makes the difference of polarization directions between a light beam which goes from the wavelength conversion element 1 to the reflecting mirror 20 and a light beam which is reflected by the reflecting mirror 20 and returns to the wavelength conversion element 1, into 90 degrees. The intensity IL of output light is made constant without depending on the incident polarizing angleϕof signal lightλs.</p> |
