During the Anime Expo in France, the president of A-1 Pictures , Tomonori Ochikoshi , revealed that the studio has no plans to reduce production of future seasons of the Sword Art Online , as long as the author Reki Kawahara continues to write more volumes of the light novel.
The second season of the anime covered the Mother's Rosario arc from the light novel, which is the 7th volume released in Japan. The next arc will be Alicization, covering volumes 9 through 15, the latter being the most recently released.
A-1 Pictures screened the first season in Japan between July and December 2012. An extra episode aired on December 31, 2013, and the second season of the anime, titled Sword Art Online II , began airing in 2014.
Via: crunchyrol