Convert wavelength in kilometres to terahertz [THz] Online | Free frequency-wavelength Converter

Understanding Extremely Low Frequency Waves

A kilometre (km) is a unit of length equal to 1,000 metres, and in the context of electromagnetic waves, it is used to describe extremely long wavelengths, typically in the Very Low Frequency (VLF) and Extremely Low Frequency (ELF) ranges. These wavelengths correspond to very low frequencies, usually below 300 kHz, and are commonly used in long-distance radio communication, submarine communication, navigation systems, and geophysical research.

For instance, a frequency of 30 kHz has a wavelength of 10 km, while 3 kHz corresponds to a wavelength of 100 km. These long wavelengths can travel great distances, penetrate seawater, and diffuse around obstacles, making them ideal for communication with submerged submarines and in areas where traditional signals cannot reach. ELF waves, with wavelengths of hundreds to thousands of kilometres, are also used in Earth monitoring, such as detecting seismic or lightning activity.

Using kilometres to measure wavelength allows scientists and engineers to understand and design systems for global communication and natural signal monitoring. Although challenging to generate and detect, kilometre-scale wavelengths play a vital role in specialized but critical applications.

Bridging the Gap Between Microwaves and Infrared

The terahertz (THz) is a unit of frequency equal to 1 trillion hertz (10¹² Hz), or one trillion cycles per second. This frequency range lies between the microwave and infrared regions of the electromagnetic spectrum, often called the "terahertz gap" because it is challenging to generate and detect these waves efficiently.

Terahertz waves have unique properties that make them valuable for a variety of scientific, medical, and security applications. In medical imaging, terahertz radiation can penetrate clothing and other non-metallic materials without the harmful effects associated with X-rays, making it promising for non-invasive diagnostics. In security, terahertz scanners are used to detect concealed weapons and substances at airports.

In physics and material science, terahertz spectroscopy helps analyze molecular structures, chemical compositions, and semiconductor properties with high precision. The high frequency of terahertz waves also makes them useful in ultra-fast wireless communication technologies aiming to provide data transfer rates far beyond current Wi-Fi and 5G speeds.

Despite its potential, terahertz technology is still developing, with ongoing research focused on improving sources and detectors to unlock more practical and widespread applications.