György Szigeti worked together with Zoltán Bay on metal-vapor lamps and fluorescent light sources. They received a U.S. patent on "Electroluminescent light sources" which were made of silicon carbide; these light sources were the ancestors of light-emitting diodes (LEDs).[1]
In 1955, Zoltán Bay became head of the Department of Nuclear Physics in the National Bureau of Standards (NBS, called today NIST), where he measured the velocity and frequency of light by a previously unknown measurement method.[2][failed verification] As a result of Bay's research, the 1983 conference of the International Weights and Measures Bureau accepted, as a standard, the definition of a meter (metre)[3] as recommended by Zoltán Bay.
^ abcd"Fizikai Szemle 1999/5 - Zsolt Bor: OPTICS BY HUNGARIANS" (with Zoltán Bay), József Attila University, Szeged, Hungary, 1999 KFKI-Hungary-Bor
^"Zoltán Bay, whose name the Foundation bears" (life), Bay Zoltán Institute of Logistics and Production Engineering (Bay-Logi), Bay Zoltán Foundation for Applied Research, 1994, webpage:BZLogi Biography at Bay Zoltán Foundation.
^Zoltán Lajos Bay – his activity to save Jews' lives during the Holocaust, at Yad Vashem website(link appears to be to another Bay family Rozalia Zemlyanskaya-Bay rescuer #8947 of Ukraine)