Wireless communication can occur through various methods such as infrared, ultraviolet, and free-space optical links. Several papers are cited that evaluate the performance of non-line-of-sight ultraviolet and free-space optical communication systems over turbulence channels. Experimental results on ultraviolet systems demonstrate their effectiveness in short-range applications. Models for dichroic mirrors in antennas and techniques like using a reference continuous wave light are discussed to improve the error rate performance and capacity of free-space optical transmission systems.