A circuit for driving a semiconductor laser including a semiconductor
integrated circuit, which controls the drive of the semiconductor laser,
and is connected to one end of the semiconductor laser. Moreover, the
driving circuit incorporates a first power source +Vcc that supplies by
way of the semiconductor integrated circuit a drive voltage to one end of
the semiconductor laser and a second power source -Vcc, which is
connected to the other end of the semiconductor laser and supplies a
drive voltage to the other end. Furthermore, the drive circuit
incorporates a voltage clamp circuit, connected to a connection terminal
connecting the semiconductor laser and the semiconductor integrated
circuit, for adjusting the electric potential of the connection terminal.