초록 ▼

A reference-voltage generator controls the level of a reference voltage in dependence upon temperature, and a drive-current supply unit passes a drive current through a semiconductor laser when the voltage of an input signal is greater than (or less than) the reference voltage. Even if a threshold-v

A reference-voltage generator controls the level of a reference voltage in dependence upon temperature, and a drive-current supply unit passes a drive current through a semiconductor laser when the voltage of an input signal is greater than (or less than) the reference voltage. Even if a threshold-value current of the semiconductor laser increases owing to a rise in ambient temperature, as a result of which there is an increase in the delay time of the optical power waveform of the laser, the reference voltage declines in conformity with the temperature rise and the time at which drive current begins to flow into the semiconductor laser is made earlier. This offsets the delay time so that a stabilized optical power waveform and optical output power are generated. In addition, a drive-current controller increases the value of drive current in conformity with a rise in temperature. As a result, the drive current which flows through the semiconductor laser increases in dependence upon the temperature rise. A stabilized optical output power is thus generated.

대표청구항 ▼

A semiconductor laser drive for driving a semiconductor laser, comprising: a drive-current supply unit for receiving an input voltage and a reference voltage and for passing a drive current through the semiconductor laser when said input voltage is greater than the reference voltage and when said in

A semiconductor laser drive for driving a semiconductor laser, comprising: a drive-current supply unit for receiving an input voltage and a reference voltage and for passing a drive current through the semiconductor laser when said input voltage is greater than the reference voltage and when said input voltage is less than the reference voltage; a drive-current controller for controlling a value of the drive current: and a reference-voltage generator for generating and outputting the reference voltage and for lowering the level of the reference voltage in dependence on a rise in a temperature of the laser, wherein said reference-voltage generator includes a voltage divider circuit having a resistor and a temperature-sensitive variable resistor element.