A system includes a high-power laser surface unit capable of generating a high-power laser beam having an output power of at least 10 kW, an optical fiber connected to the high-power laser surface unit, and at least one harvesting cell disposed around the optical fiber. The optical fiber includes an optical cladding surrounding an optical fiber core. Each harvesting cell includes an anode, a cathode, and a thermoelectric layer disposed adjacent to and electrically connected to the anode and the cathode, where the thermoelectric layer includes a polymer-based thermoelectric material.