GAIN REDUCTION COMPENSATING CIRCUIT OF LASER DIODE

摘要

PURPOSE: A circuit for compensating for a reduction of a gain of a laser diode is provided to compensate for a reduction of a radio frequency gain by moving a direct current bias point according to the increase of a peripheral temperature of the laser diode. CONSTITUTION: A capacitor(20) receives a radio frequency signal. A resistor(21) performs 50 ohm impedance matching together with an automatic power circuit. The capacitor(20) intercepts a direct current component of a received radio frequency signal and outputs an alternating current component thereof. A laser diode(22) converts and transmits an input current into a light. A monitoring photo diode(23) senses amount of the light and converts the light into the current. Amplifiers(24,25) amplify an input little current. A diode(26) performs a function of controlling an amplification when an input becomes a predetermined voltage. An inductor(27) removes an alternating current component and provides a direct current component from an input signal.