| 摘要 |
PURPOSE:To separate and detect multiple light signals of different wavelengths at high efficiency by cascade-arraying photo detecting elements of different wavelength dependencies of absorption coefficients. CONSTITUTION:When the light waves of wavelengths lambda1(0.8mum, etc.), lambda2(1.3mum, etc.) emitted from an optical fiber 15 are collected at a silicon photo diode 18 by a light-beam-forcusing lens 16, the light wave of the wavelength lambda1 is absorbed by this and is converted to an electric signal which is then detected in a detecting circuit 20. The light wave of the wavelength lambda2 transmits through the diode 18 and is collected at a germanium photo diode 19 by a light-beam-focusing lens 17 and is converted to an electric signal which is then detected in a detecting circuit 21. In this way, the multiple light signals of different wavelengths may be separated and detected at high efficiency. |
