Spin–orbit laser mode transfer via a classical analogue of quantum teleportation

Abstract

We translate the quantum teleportation protocol into a sequence of coherent operations involving three degrees of freedom of a classical laser beam. The protocol, which we demonstrate experimentally, transfers the polarisation state of the input beam to the transverse mode of the output beam. The role of quantum entanglement is played by a non-separable mode describing the path and transverse degrees of freedom. Our protocol illustrates the possibility of new optical applications based on this intriguing classical analogue of quantum entanglement.

Experimental investigation of environment-induced entanglement using an all-optical setup

“…They allow encoding of quantum information units (qubits or qudits) in different degrees of freedom of the light field, such as polarization, transverse mode or longitudinal path. This kind of encoding has already been used to investigate the topological phase acquired by entangled qubit pairs [55,56], quantum inequalities [57][58][59][60][61][62][63], quantum cryptography [55,64], quantum image control [65], quantum gates [66,67], quantum simulations [68], teleportation schemes [69][70][71][72][73][74], discrete [70] and continuous variables [75,76] hyperentanglement. It has also been used to study entanglement dynamics under the action of the environment [35,77,78], where the role of the environment is usually played by the longitudinal path, while the other degrees of freedom represent the quantum systems of interest.…”

Polarization-based control of spin-orbit vector modes of light in biphoton interference

“…4 have been previously produced by others using a structured optical fiber [40], and a number of interferometry-based schemes have been employed for the measurement and manipulation of similar mode types (e.g. [41][42][43]. In contrast with this previous work, here we have produced nonseparable modes in a four-port device capable of exhibiting biphoton interference in conjunction with a mode conversion from separable to nonseparable modes, demonstrated above in Figs.…”

Nonseparable States of Light: From Quantum to Classical

“…[158,99] Besides the pure state systems, the quantum mechanics of mixed state was also transferred to complex classical beams for exploring high-dimensional quantumanalogue system, [162] which can also realize the counter-intuitive quantum teleportation effect in classical beams system. [163,164] In a similar way, the concept of nonseparability has been also used for spatiotemporal quantum-analogue pulses, for example, the Schmidt number or Schmidt rank was used to characterize the invariant propagation effect of a classical pulse. [101] Since the quantum state tomography method was modified to highdimensional state, [162] we can apply analogous method to more complex structured light, for example, the space-time nonseparable pulses, and many quantum concepts (fidelity, concurrence, linear entropy, etc.)…”