YAG

Yttrium Aluminum Garnet. A type of glass used as the lasing medium of high-power, optically pumped lasers. Also refers to a laser of this type. The YAG material must be doped with a rare earth element – most often neodymium (Nd), but sometimes erbium (Er), ytterbium (Yb), holmium (Ho), or even thulium (Tm). These lasers are common in surgery and welding.

Yagi

See antenna.

YCbCr

A non-linear variation of the RGB scheme for digital video. Y represents luminance (brightness), and CbCr represents chrominance – absolute color values without regard to brightness.

YIG

Yttrium Iron Garnet. A ferromagnetic material used in microwave and fiber-optics devices and as a laser medium. Magnetically saturated YIG can change the polarization of light (the Faraday effect). It’s transparent to wavelengths longer than 600 nm, meaning infra-red, red, and some orange light.

Ymodem

See data protocol.