| 摘要 |
PURPOSE:To eliminate deterioration in transmission characteristics due to reflection and to perform multidrop transmission by coupling a laser diode with plural optical fibers so that remote distances from the laser light emission surface to end surfaces are short enough to ignore the influence of reflection. CONSTITUTION:Analog modulation is imposed upon the laser diode 2 by a signal generated by amplifying 1 a multiplex video signal. The light emission surface of the diode 2 and end surfaces of optical fibers 3a-3c are set at such a remote distance that the influence of reflection is ignored, and the diode 2 is coupled with the fibers 3a-3c. Light signals from the diode 2 transmitted by the fibers 3a-3c are converted by photodiodes 5a-5c into electric signals, which are amplified to 6a-6c. Analog modulation is imposed upon a laser diode 7 by a signal generated by the amplification 6b to reconvert into a light signal, which is transmitted by coupling the diode 7 with optical fibers 3d-3f at similar remote distances. Consequently, a reflected wave from an optical fiber end surface or in a transmission line less enters the laser diode again to prevent deterioration in transmission characteristics. |
