| 摘要 |
PURPOSE:To attain stable transmission/reception based on an electric signal of a nearly constant level at each terminal equipment by providing a signal coupler having two directional optoelectric signal converting circuits between an optical fiber transmission line and each terminal equipment respectively. CONSTITUTION:Plural terminal equipments 2 are connected to the optical fiber transmission line l via a signal coupler 4 respectively and the coupler 4 has two directional photoelectric signal conversion circuits comprising electrooptic converters 7-L,7-R and photoelectric converters 8-L,8-R. Thus, the optical signal in wavelength lambda1 or lambda2 sent in right or left direction on the transmission line l is received by each equipment 2 in a form of an electric signal via the coupler 4 and the transmission optical signal to the right or left adjacent equipment 2 is generated newly. Thus, the output light power of the converters 7-L,7-R is enough to be a level sent to the adjacent coupler 4 and each equipment 2 makes stable transmission/ reception based on an electric signal of nearly constant level to improve the reliability. |
