Tatsushi Hamaguchi (Senior Scientist) was born in Osaka, Japan in 1980. He received the B.S. and M.S. degrees in material science and engineering from Kyoto University in 2004 and 2006. He received the Ph.D. degree in electronic engineering from Sophia University in 2019. From 2006 to 2008, he worked at the Nitride Semiconductor Research Laboratory of Nichia Corporation. After 2008, he worked for Sony corporation, where he did development of nitride-based edge-emitting lasers and vertical-cavity surface-emitting lasers (VCSELs). He has acted as the leader of the Sony’s project team for nitride-based VCSELs during the recent years and awarded “Sony Outstanding Engineer Award 2018“.