To transmit a high capacity over 100 Tbps/fiber and long-haul transmission, the multiplexing techniques that are needed to break this bottleneck/capacity limit are termed space-division multiplexing, which uses single mode fiber (SMF) and multicore fiber (MCF). In my previous blogs, I discussed various ways to improve the data transmission capacity of optical fiber networks given the unrelenting pace at which bandwidth demand is forecast to grow over the next decade (~40 percent/year). There are different multiplexing techniques like frequency-division multiplexing (FDM), time-division multiplexing (TDM), wavelength division. This essay explores the various techniques and technologies employed to increase fiber optic capacity, examining the underlying principles, practical implementations, and future trends. Most long-distance fiber optic communication relies on single-mode fiber (SMF). single-mode optical fiber has increased by a staggering 10 000 times.