A laser diode drive circuit includes a first transistor having a collector connected to an anode of a laser diode; a second transistor having a collector connected to a cathode of the laser diode; a constant current circuit connected between a ground point and emitters of the first and second transistors; a first high-pass filter connected between the base and the collector of the first transistor; and a second high-pass filter connected between the base and the collector of the second transistor.