He has been considered by some to be "the Edison of France". Claude was an active collaborator with the German occupiers of France during the Second World War, for which he was imprisoned in 1945 and stripped of his honors.
Inspired by Geissler tubes and by Daniel McFarlan Moore's invention of a nitrogen-based light (the "Moore tube"), Claude developed neon tube lighting to exploit the neon that was produced as a byproduct of his air liquefaction business. These were all "glow discharge" tubes that generate light when an electric current is passed through the rarefied gas within the tube. Claude's first public demonstration of a large neon light was at the Paris Motor Show (Salon de l'Automobile et du Cycle), 3–18 December 1910. Claude's first patent filing for his technologies in France was on 7 March 1910.
Claude himself wrote in 1913 that, in addition to a source of neon gas, there were two principal inventions that made neon lighting practicable. First were his methods for purifying the neon (or other inert gases such as argon). Claude developed techniques for purifying the inert gases within a completely sealed glass tube, which distinguished neon tube lighting from the Moore tubes; the latter had a device for replenishing the nitrogen or carbon dioxide gases within the tube. The second invention was ultimately crucial for the development of the Claude lighting business; it was a design for minimizing the degradation (by "sputtering") of the electrodes that transfer electric current from the external power supply to the glowing gases within the sign.
The terms "neon light" and "neon sign" are now often applied to electrical lighting incorporating sealed glass tubes filled with argon, mercury vapor, or other gases instead of neon. In 1915 a U.S. patent was issued to Claude covering the design of the electrodes for neon lights; this patent became the strongest basis for the monopoly held in the U.S. by his company, Claude Neon Lights, through the early 1930s.
In 1923, Georges Claude and his French company Claude Neon, introduced neon gas signs to the United States, by selling two to Earle C. Anthony, the owner of Packard car dealerships in San Francisco and Los Angeles. Photos from 1923 of the one in San Francisco show the neon Packard sign. Neon lighting quickly became a popular fixture in outdoor advertising. Visible even in daylight, people would stop and stare at the first neon signs for hours, dubbed "liquid fire."
According to wikipedia