What is submilimeter wave?

The word "submillimeter" is prefixed with sub- which means "below", "less than", or "under something". (For example, subzero: "below zero" (temperature), or submarine: "under water".) So submillimeter wave wavelengths are slightly smaller than millimeters, presenting electromagnetic waves between 0.3 to 1 millimeters.

On the electromagnetic spectrum, the submillimeter band is between infrared and microwave, with a frequency of 300-900 GHz.

Image credits: ALMA/ ASIAA, illustration by Frannerd,

Chinese characters were handwritten by Anchi Shen 

edited by Lauren