| 摘要 |
PURPOSE:To reduce the distortion of a pulse waveform of a laser output by branching a current flowing to a laser diode at the time of non light emission by a resistor having a negative temperature coefficient. CONSTITUTION:Part of a laser light output radiated from a laser diode 1 is detected by a driving power source 3 to supply a driving current 4 to the diode 1 so that its optical output becomes constant, and the current 4 is branched to a resistor 2 and the diode 1 when a pulse modulator 5 is closed. In this case, when a negative characteristic thermistor having a negative temperature coefficient is employed as the resistor 2, the resistance value of the resistor 2 is reduced due to a temperature rise, the current value flowing to the diode 1 may become constant for the threshold value of the diode even when the modulator 5 is closed. Thus, a laser device can be so obtained that the output waveform of the laser is not deformed. |
