Thorlabs’ 1x2 multimode fused fiber optic couplers, also known as taps, allow a single fiber input to be split into two outputs. Couplers fabricated from graded-index (GRIN) fiber are available with Ø50 µm or Ø62.5 µm core sizes. Couplers made using step-index fiber are are offered with core diameters ranging from 50 µm to 600 µm and numerical apertures from 0.22 to 0.50. Options are available with ferrule-terminated fiber leads for optogenetics applications.