various embodiments of a novel method and design for coupling optical signals from a lens array to a fiber array subassembly with locking capability in a pluggable form factor are provided . optical signals vertically emitted from a vertical - cavity surface - emitting laser array on a printed circuit board are coupled into an optical coupling lens array , which are then coupled into a fiber array subassembly parallel to the pcb . a locking device in a pluggable form factor provides means for mating and locking between the lens array and the fiber array subassembly , thereby achieving good coupling and locking between the fiber array subassembly and lens array .