The act of dividing an incident optical beam into multiple paths, usually by reflection and transmission at a partially mirrored surface, a polarizing interface, or a diffractive element. This is a fundamental operation in interferometry, pump-probe setups, and optical routing, dictating how power and polarization are distributed across a lab table.
Heard on the job
The beamsplitting in this interferometer needs to be exactly 50/50, or our fringe contrast will drop.