| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser driving circuit which can make an eye pattern satisfy a specified eye mask by making the rising time and falling time of a waveform shorter when pulse-modulated signals are supplied to a vertical cavity surface emitting laser(VCSEL). SOLUTION: A resistor R is connected in series with a VCSEL and a direct bias current Ibias is supplied to the VCSEL and resistor R from a direct bias current supplying circuit 1 through an inductor L. Inputted data are inputted to a voltage amplifier 3 from differential inputs TX+ and TX-through a PECL(positive referenced emitted-couple logic) inputting buffer 2 and, after the voltage is amplified, the voltage is damped by means of an attenuator 7, sent to a transmission line 8 through an AC coupling capacitor C, and impressed upon the resistor R and VCSEL. The voltage amplifier 3 is constituted in such a way that the amplifier 3 has peaking in its frequency characteristic and the gain, frequency band, and peaking characteristic of the amplifier 3 can be adjusted. |
