  Noise poses a challenge for any real-world implementation in quantum
information science. The theory of quantum error correction deals with this
problem via methods to encode and recover quantum information in a way that is
resilient against that noise. Unitarily correctable codes are an error
correction technique wherein a single unitary recovery operation is applied
without the need for an ancilla Hilbert space. Here, we present the first
optical implementation of a non-trivial unitarily correctable code for a noisy
quantum channel with no decoherence-free subspaces or noiseless subsystems. We
show that recovery of our initial states is achieved with high fidelity
(>=0.97), quantitatively proving the efficacy of this unitarily correctable
code.
