THz vs. FSO: An Outage Probability and Channel Capacity Performance Comparison Study

The main subject of this work is to make a detailed comparison between the performance of free-space optical (FSO) and terahertz (THz) links under different conditions. To this end, we first perform a detailed modeling of the FSO and THz channels, taking into account all real channel parameters. Then we compare the performance of THz and FSO links using two important wireless communication performance metrics, i.e., channel capacity and outage probability. We mathematically show that, unlike FSO links, the pointing errors of THz links are not function of linklength. Finally, by examining the strengths and weaknesses of both technologies, we show that increasing the linklength has a more destructive effect on FSO links compared to the THz links. For shorter linklength, FSO links have better performance, however, with the increase in linklength, THz has the ability to reach higher capacity than FSO links.