| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical limiter capable of limiting the power of a generated optical surge, reducing the number of parts and having high reliability as a device. SOLUTION: The optical limiter is provided with a parametric amplifier element 22 for amplifying inputted signal light S11 as an optical parameter and a wavelength selecting element 23 for removing wavelength components other than the signal light S11 of the prescribed wavelength from signal light S12 outputted from the element 22. Since the power of signal light is converted into the power of noise light of neighbor wavelength by the element 22, the width of an optical spectrum is expanded and wavelength components other than the signal light are removed by the element 23, optical surges capable of destructing/deteriorating system constitutional parts including a light receiving element can be limited. |
