Terahertz radiation does have a relatively short wavelength compared to other regions of the electromagnetic spectrum. It falls between the microwave and infrared regions and spans frequencies from around 0.1 to 10 terahertz (10^12 Hz). The corresponding wavelengths range from approximately 30 micrometers to 3 millimeters.
In terms of technology and sources, generating and manipulating terahertz radiation has posed some challenges, particularly in the past. However, significant progress has been made in recent years, and there has been a growing interest in terahertz technology.
Historically, developing efficient and practical terahertz sources and detectors has been more challenging compared to other regions of the electromagnetic spectrum. This was due to the lack of suitable semiconductor materials and devices that can operate in the terahertz frequency range. Additionally, terahertz waves are strongly absorbed by water vapor, making it difficult to transmit them over long distances through the atmosphere.
However, advancements in semiconductor technology, such as the development of high-speed electronics and compact solid-state devices, have facilitated the generation and manipulation of terahertz waves. Today, there are various methods and technologies available for generating terahertz radiation, including optical rectification, quantum cascade lasers, and terahertz time-domain spectroscopy systems.
Terahertz technology has found applications in fields such as imaging, spectroscopy, communications, and security screening. With ongoing research and technological advancements, the use of terahertz radiation is expected to continue expanding, enabling new possibilities and applications in the future.