Abstract

We present a concept of an optical vortex ladder for stepwise generation of optical vortices through Sisyphus pumping of pseudospin modes in photonic graphene. By exciting a ring spectrum around the Dirac cone and periodically kicking the lattice at specific propagation lengths, the probe beam is converted into vortices with increasing topological charge at each stage. The approach combines complete pseudospin conversion, topological protection, and diffraction-free propagation, and is demonstrated experimentally in a photorefractive photonic graphene lattice.

Abstract

We present a concept of an optical vortex ladder for stepwise generation of optical vortices through Sisyphus pumping of pseudospin modes in photonic graphene. By exciting a ring spectrum around the Dirac cone and periodically kicking the lattice at specific propagation lengths, the probe beam is converted into vortices with increasing topological charge at each stage. The approach combines complete pseudospin conversion, topological protection, and diffraction-free propagation, and is demonstrated experimentally in a photorefractive photonic graphene lattice.

Abstract

We present a concept of an optical vortex ladder for stepwise generation of optical vortices through Sisyphus pumping of pseudospin modes in photonic graphene. By exciting a ring spectrum around the Dirac cone and periodically kicking the lattice at specific propagation lengths, the probe beam is converted into vortices with increasing topological charge at each stage. The approach combines complete pseudospin conversion, topological protection, and diffraction-free propagation, and is demonstrated experimentally in a photorefractive photonic graphene lattice.

Abstract

We present a concept of an optical vortex ladder for stepwise generation of optical vortices through Sisyphus pumping of pseudospin modes in photonic graphene. By exciting a ring spectrum around the Dirac cone and periodically kicking the lattice at specific propagation lengths, the probe beam is converted into vortices with increasing topological charge at each stage. The approach combines complete pseudospin conversion, topological protection, and diffraction-free propagation, and is demonstrated experimentally in a photorefractive photonic graphene lattice.