Single-mode research focuses on the study of optical fibers that have the ability to transmit light in a single mode or path. This allows for more precise and efficient transmission of signals, particularly in telecommunications and data transmission applications. Single-mode fibers have a smaller core size compared to multi-mode fibers, which results in less dispersion and attenuation of the light signal. Researchers in this area work on improving the performance and characteristics of single-mode fibers, as well as developing new technologies and applications for their use.