Extender apparatus for an optical network includes first and second extender units having an network-facing port for connection to a backhaul fiber and a subscriber-facing port for connection to a feeder fiber. Specifically, the power supply circuitry may include a first power supply circuit, which may be a switching power supply circuit, a second power supply circuit, which may be a linear power supply circuit and may include the energy storage element, and control circuitry to facilitate efficient power transfer. Each of the heat exchangers is in fluid communication with one of the chambers.