  We introduce a multi-step protocol for optical quantum state engineering that
performs as deterministic "bright quantum scissors" (BQS), namely truncates an
arbitrary input quantum state to have at least a certain number of photons. The
protocol exploits single-photon pulses and is based on the effect of
single-photon Raman interaction, which is implemented with a single three-level
$\Lambda$ system (e.g. a single atom) Purcell-enhanced by a single-sided
cavity. A single step of the protocol realises the inverse of the bosonic
annihilation operator. Multiple iterations of the protocol can be used to
deterministically generate a chain of single-photons in a W state.
Alternatively, upon appropriate heralding, the protocol can be used to generate
Fock-state optical pulses. This protocol could serve as a useful and versatile
building block for the generation of advanced optical quantum states that are
vital for quantum communication, distributed quantum information processing,
and all-optical quantum computing.
