Terafar science is the study of generating terahertz electromagnetic waves (femtosecond lasers) using femtosecond lasers, analyzing their characteristics, and applying them to physics, chemistry, biology, and electronics. In this laboratory, the output of a femtosecond Ti: sapphire laser pumped by a diode-pumped green laser is incident on a photoconductor composed of semiconductors, etc. to generate terahr waves, and photoconductive sampling or electro-optical sampling - optic sampling). The characteristics of this terra wave are analyzed not only by experiment but also by theoretical tools such as FD-TD, space and time. Typical applications of teraflas in this laboratory include solid-state femtosecond time-varying physical properties of semiconductors, analysis of harmful environmental gases such as dioxins, and teraphor imaging. In the future, we will expand the field of research to the research and production of various teraflop devices that can realize terahertz communication.