| 摘要 |
PROBLEM TO BE SOLVED: To provide the signal converting device which can convert the wavelength of signal light to arbitrary wavelength at a stable output level. SOLUTION: This device is equipped with a light source 2 which emits a CW light of specific wavelengths λ-1 to λn a saturable absorption type optical element 1, and a wavelength branching circuit 3 which demultiplexes the signal light emitted by the optical element 1 into a signal light of desired wavelength. Then the signal light of wavelength λs and the CW light outputted by the light source 2 are inputted to the optical element 1 so that they individually have light intensity levels lower than the threshold level of optical transmission and when there is a signal, the total light intensity level of the both is higher than the threshold level of optical transmission. |
