| 摘要 |
PURPOSE:To obtain transmission of a multiple wavelength signal over a wide wavelength band by converting an optical long wavelength in a long wavelength band for which a photoelectric element is low in sensitivity into a optical short wavelength band for which its sensitivity is high. CONSTITUTION:When optical signals of three kinds, lambdaS1, lambdaS2, lambdaS3, of wavelength are sent through optical fiber 1, optical beams of lambdaS2, lambdaS3 is separated to the right and that of lambdaS1 is separated downward in a branching filter 2. Optical beams of lambdaS2 and lambdaS3 is separated in a branching filter 3 and converted respectively to electric signals in photodetectors 82, 83. The optical beam of lambdaS1 is combined with optical wavelength lambdaP of exciting light source 5 by a combining device 4, passes through a non-linear medium 6 such as an optical fiber etc., and converted into optical short wavelength lambdaS1. Then, other optical wavelength is removed by a bandpass filter, and converted to electric signal by a photodetector 81. |
