LASER DIODE DRIVING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To suppress waveform degradation without the need of temperature control by connecting a bias circuit across a laser diode and applying a bias voltage across the laser diode when the bias circuit receives bias control signals generated a fixed time before the input of the first bit of burst signals. SOLUTION: The bias control signals are inputted through a bias resistor r3 to the base of a transistor TR3. The fixed time before the burst signals DATA are inputted to the base of the transistor TR2, the bias control signals are inputted through the bias resistor r3 to the base of the transistor TR3. Thus, a power source Vcc is applied through a diode D1 to the collector of the transistor TR3 and the laser diode LD is biased by the voltage drop of the diode D1. A normal optical output waveform without waveform degradation by the input of the burst signals DATA is obtained.