Quantum state engineering with twisted photons via adaptive shaping of the pump beam

Understand

High-dimensional entanglement is a valuable resource for quantum communication, and photon pairs entangled in orbital angular momentum are commonly used for encoding high-dimensional quantum states.

• However, methods for preparation of maximally entangled states of arbitrary dimensionality are still lacking, and currently used approaches essentially rely on filtering and entanglement concentration.
• Here we experimentally realize a method for generation of high-dimensional maximally entangled OAM states of photon pairs which does not require any of these procedures.
• Moreover, the prepared state is restricted to the subspace of the specified dimensionality, thus requiring minimal postselection.