This is a trivia question that has bugged me for many years. NO ONE has been able to give a satisfactory answer. In the early 80's , all the catalogs ( Newark, Allied, Derf etc ) listed the 4n32, 4n40 etc as Photon Couplers....Very Star trekkish.! Then...sometime in the late 90s ?....I blinked and these wonderful devices suddenly were called "Opto isolators"...( how Boring ). All MY schematics will always show them the PROPER way!.. but the rest of the world marches to the tune of the Boring Name..... I would love to know when the change was made...By WHOSE authority ....and mostly WHY would the industry do this? Thank you , in advance!