Terahertz is a unique frequency domain since it lies between the regimes of electronics and photonics and there has been intense activity from both electronics and photonics route to bridge the so-called “Terahertz gap” between the microwaves and optical spectrum. While the 1970s belonged to microwaves followed by optical fiber-based internet era developed by photonics, the future belongs to terahertz waves that hold the potential for key technologies such as 6G wireless communications, smart sensors, homeland security and cancer treatment with tera-medicines. The futuristic terahertz technologies are based on material response to terahertz fields that would enable terahertz multifunctional and disruptive devices.