This disclosure is directed to, among other things, techniques to quickly replenish a capacitance of a laser diode driver circuit after an optical pulse, which can enable a burst of pulses (more than one pulse), such as to enable pulse coding. An energy reservoir circuit can be coupled to a laser diode driver circuit and to a power supply circuit and configured to store enough energy to fire the RD laser diode driver more than once. The energy reservoir circuit can act as an intermediate interface between the RD laser diode driver and the power supply circuit to better optimize the current requirements of each block.