| 摘要 |
PROBLEM TO BE SOLVED: To obtain an excellent optical output waveform by adding a reflection absorption circuit absorbing a reflecting wave caused around a light emitting element between the light emitting element and a drain of a field effect transistor(FET) applying a signal to the light emitting element so as to supply excellent drive current waveform to the light emitting element. SOLUTION: The transmitter is made up of an input buffer 1 of a differential configuration, FETs 2, 3 of differential configuration providing an output of a noninverting or an inverting signal, a FET 4 acting like a constant current source, an LD(laser diode) 5 as a light emitting element, an LD bias supply circuit 6 controlling a bias current of the LD5 and a reflection wave absorbing circuit 7. A drain of the FET 3 is connected to a cathode of the LD 5 as a light emitting element via the reflection wave absorbing circuit 7 to apply a desired current therethrough to light up the LD 5 and to provide an output of the optical signal. A reflected wave is caused around the LD 5 and the reflection wave absorbing circuit 7 absorbs the reflecting wave to suppress deterioration in the optical output waveform of the LD 5. |
