A microwave kinetic inductance detector (MKID) is a type of detector that uses the kinetic inductance of a superconducting material to detect microwaves. The basic principle behind MKIDs is that when microwaves are incident on a superconducting material, they cause the electrons in the material to move. This movement of electrons causes a change in the magnetic field, which can be detected by an external magnetometer.
MKIDs have several advantages over traditional detectors, such as bolometers. For example, MKIDs are much more sensitive than bolometers, and can be used to detect very weak signals. In addition, MKIDs do not require cryogenic cooling, making them much more practical for use in real-world applications. Finally, MKIDs can be multiplexed, meaning that many MKIDs can be used together to create a large array of detectors.
There are two main types of MKIDs: single-pixel and multi-pixel. Single-pixel MKIDs consist of a single superconducting element, while multi-pixel MKIDs consist of an array of superconducting elements. Multi-pixel arrays offer several advantages over single-pixel arrays, such as increased sensitivity and the ability to resolve complex images.
While still in its early stages of development, microwave kinetic inductance detection has great potential for a variety of applications including astronomical observations from ground and space telescopes