Pump lasers are an emerging bottleneck that favors Lumentum, Coherent and Furukawa Electric. Used to amplify signals in undersea cables and increasingly in data-center-to-data-center links, pump laser volumes will quadruple within a year or two, per Needham. Despite using gallium arsenide, quality pump lasers are very hard to mass produce given power and reliability demands. @Gaurab notes even Amazon can't get a new submarine cable before 2028, with SubCom holding a record $4.7 billion backlog. x.comÂ
