| 摘要 |
PURPOSE:To obtain a high frequency superposing device for a multi-beam optical head which can obtain an amplitude of a necessary high frequency signal without reducing the amplitude of the signal to be superposed and applied to a semiconductor laser element for constituting the head to suppress return light noise even if output beams of differential amplifiers are coupled due to electromagnetic induction and can stably reproduce it by suppressing a decrease in S/N at the time of reproducing by the head. CONSTITUTION:One semiconductor laser element 2 of a multi-beam semiconductor laser 1 is connected to one semiconductor laser driving circuit 3, and an oscillation output of a high frequency oscillator 4 is distributed to differential amplifiers 8 for a buffer through a distributing differential amplifier 7 in an equilibrated differential manner. A high frequency signal is so applied to a DC current of the element 2 that the signal to be applied and superposed to the adjacent element 2 becomes a reverse phase. |
