Analysis and measurement on drive current characteristics of 905nm InGaAs pulse laser diodes

In order to realize the adjustment of pulse width and peak power of a high power 905nm InGaAs pulse laser diode, field-programmable gate array (FPGA) was adopted to generate trigger pulse, the integrated module EL7104C was used as the driver of metal oxide semiconductor field effect transistor (MOSFET) and the switching device with MOSFET as the core was used to control the charging and discharging between the high voltage module and energy storage capacitor. The pulsed laser diode driver circuit was designed. The driving current characteristics were theoretically analyzed and experimentally verified. Pulse width and peak data were obtained under different capacitance and high voltage conditions. The specific change relationship was analyzed. The spectrum and power-current characteristics were tested. The results show that, the key factors affecting the driving current pulse width and peak current were the capacitor size and charging voltage. The pulse laser diode can be controlled with peak drive current from 0A to 40A and pulse width from 20ns to 100ns. The maximum peak power output of pulsed laser diode is up to 40W. The controllable modulation of output power and pulse width of a pulsed semiconductor laser is realized. The design and analysis have practical reference significance for the controllable driving design of near infrared high power pulsed lasers.