| 摘要 |
PURPOSE:To prevent generation of background light due to naturally irradiated light from a laser diode by adding a switch means operated synchronously with a transmission request signal in an optical transmitter transmitting intermittently data. CONSTITUTION:Transmission data 2 is applied to a transistor (TR)16 synchronously with a transmission request signal 15. The TRs 16, 17 form a current changeover switch. When the request signal 15 reaches a threshold voltage 18 of the TR17, an output current of a current amplifier 5 is outputted to the laser diode 4 as a bias current 6 via the TR16. On the other hand, when the request signal 15 reaches a voltage 18 or below, the output current of the amplifier 5 is outputted to a load 19 via the TR17. Through the operation above, no current flows to the diode 4 at all at the non-transmission system, then no background optical output light due to naturally irradiated light is caused. |
