  The capability to generate and manipulate quantum states in high-dimensional
Hilbert spaces is a crucial step for the development of quantum technologies,
from quantum communication to quantum computation. One-dimensional quantum walk
dynamics represents a valid tool in the task of engineering arbitrary quantum
states. Here we affirm such potential in a linear-optics platform that realizes
discrete-time quantum walks in the orbital angular momentum degree of freedom
of photons. Different classes of relevant qudit states in a six-dimensional
space are prepared and measured, confirming the feasibility of the protocol.
Our results represent a further investigation of quantum walk dynamics in
photonics platforms, paving the way for the use of such a quantum
state-engineering toolbox for a large range of applications.
