A laser driver subsystem includes a pump diode driver, operable to generate light pulses to energize a laser, and a lithium polymer battery. The pump diode driver includes a pump diode and a switched-mode power conversion circuit at an input connected to an output of the battery and at an output connected to an anode of the pump diode. The switched-mode power conversion circuit is configured to convert an electrical voltage from a first level at the output of the battery to a second lower voltage level at the pump diode anode so as to provide the pump diode with an electrical current that enables the pump diode to generate the light pulses to operate the laser while only a fraction of that current needs to be supplied by the battery.