Patent ID: 6970050

Claim:
A high-frequency superposing module for driving a laser diode, comprising: an oscillator for superposing a high-frequency current for the laser diode comprising: an oscillating active element; a capacitor connected between a feedback-signal input terminal of the oscillating active element and a ground; a first bias resistor connected between the feedback-signal input terminal and a power input terminal; and a second bias resistor connected between the feedback-signal input terminal and a control-voltage input terminal; wherein the first bias resistor and the second bias resistor have values such that when the control-voltage input terminal is grounded, the bias voltage at the feedback-signal input terminal is above the ground potential and below a threshold for continuous oscillation of the oscillating active element, and when the control-voltage input terminal is open, the bias voltage at the feedback-signal input terminal is above the threshold; a drive-signal output terminal connected to the anode of the laser diode; and an impedance matching circuit connected between the drive-signal output terminal and an output section of the oscillator.