| 摘要 |
PURPOSE:To gain a photocurrent corresponding to a received wave length by a method wherein a device making use of the photosensitivity of a chemical semiconductor surface and the character of selectively receiving certain light wave lengths of a semiconductor structure and is directly coupled with the output surface of an optical fiber unit. CONSTITUTION:A Cr deped semi-insulator GaAs substrate 8 is covered by a GaAs1-xPx(X=0-1) layer 9 that is selectively and epitaxially formed, constituting a light receiving layer. A source 10, a drain 12, a gate oxide film and gate electrode 11, and a CVD SiO2 separating layer 13 are provided, thereby constituting a wave length multiplex light receiving device that can handle 4 wave lengths. When a reverse bias is applied to the gate 11, no current is outputted to reach the drain 12 thanks to a space charge layer 14. Exposure to a light beam 15 with energy larger than that of the band gap causes a channel 16 to open, the channel 16 responding selectively to the length of light supplied. By merely coupling this receiving device, consisting of a multiplicity of photodetecting cells on a single substrate, to an optical fiber unit, a light beam with a multiplicity of wave lengths may be divided by length and detected, thereby eliminating the need for spectral dividers. |
