Optical Couplers - LSTECH LSTECH’s Couplers are manufactured by fused bi-conic (FBT) technology, complying with our stringent quality control procedure. LSTECH can provide WDM, Splitters, WIC, … LSTECH’s Couplers are manufactured by fused bi-conic (FBT) technology, complying with our stringent quality control procedure. LSTECH can provide WDM, Splitters, WIC, …