A system is provided that includes a gateway node and terminal node. The gateway node includes an actuator configured to produce a light beam for propagation through a fluid, and a sensor configured to detect a reflection of the light beam. The terminal node is disposed within the fluid and includes an energy source and a photovoltaic layer adjacent to a reflective layer. The photovoltaic layer is switchably controlled between two modes, to convey a data stream associated with the reflected light beam to the sensor of the gateway node, the two modes including: a transmission mode wherein the light beam is transmitted through the photovoltaic layer and reflected by the adjacent reflective layer to the sensor of the gateway node, and a recharging mode wherein the photovoltaic layer is configured to capture photonic energy from the light beam for storage in the energy source.