Yariv group use optical PLLs to combine MOPA lasers

Wei Liang, Naresh Satyan, Amnon Yariv, Anthony Kewitsch, George Rakuljic, Firooz Aflatouni, Hossein Hashemi, and Jeffrey Ungar 2007) Coherent power combination of two Master-oscillator-power-amplifier (MOPA) semiconductor lasers using optical phase lock loops. Optics Express, 15(6):3201-3205, 19 March 2007. CaltechAUTHORS