Zoltán Lajos Bay was a Hungarian physicist, professor, and engineer who developed technologies, including tungsten lamps and
microwave devices. He was the leader of the second group to observe radar echoes from the Moon. From 1930, he worked at the University of Szeged as a professor of theoretical physics.
In 1923 at Tungsram Ltd., a research laboratory was established for improving light sources, mainly electric bulbs. The head of that laboratory was Ignác Pfeifer, whose research staff included Zoltán Bay, along with Tivadar Millner, Imre Bródy, György Szigeti, Ernő Winter, and many others.György Szigeti worked together with Zoltán Bay on metal-vapor lamps and fluorescent light sources.