In this paper we propose an in-depth investigation on energy harvesting solutions from THz to DC, deploying a dedicated laser source in the infrared (IR) region. Planar bow-tie nano-antennas with misaligned monopoles are arranged in both an array and a multi-element architecture, and combined with tunnel diodes for rectification. A highly directive IR laser is adopted as the 84-THz source, and the receiving antennas are arranged in such a way to cover an area comparable to that illuminated by the laser beam. A theoretical estimation of the overall system performance in terms of achievable DC power is provided by means of an accurate circuit/electromagnetic co-simulation.