Multiaxial super-geometric mode laser

Abstract

Structured light was usually studied by two-dimensional (2D) transverse eigenmodes. Recently, the three-dimensional (3D) geometric modes as coherent superposed states of eigenmodes opened new topological indices to shape light, that optical vortices can be coupled on multiaxial geometric rays, but only limited to azimuthal vortex charge. Here, we propose a new structured light family, multiaxial super-geometric modes, enabling full radial and azimuthal indices coupled to multiaxial rays, and they can be directly generated from a laser cavity. Exploiting combined intra- and extra-cavity astigmatic mode conversions, we experimentally verify the versatile tunability of complex orbital angular momentum and SU(2) geometry beyond the limit of prior multiaxial geometric modes, opening new dimensions to revolutionize applications such as optical trapping, manufacturing, and communications.

Ultra-Degree-of-Freedom Structured Light for Ultracapacity Information Carriers

“…In contrast to beams without ray-wave duality, the ray-wave geometric mode unveils new DoFs: frequency-degenerate ratio |Ω⟩ describes the number of rays in the ray-trajectory; coherent phase |ϕ⟩ decides the sequence and orientation of each ray in the ray-trajectory; and the previous DoF of OAM | l ⟩ can also be involved in addition to the above three new DoFs, that indicates how large the transverse size of the twisted ray-trajectory is. In addition, such ray-wave structured light can be directly generated from a laser, ,− and the various frequency-degenerate ratio can be achieved by precisely controlling the cavity geometry . Recently, the control of coherent phase state ϕ was also reported, by precise adjustment of the locations of pump spot and gain crystal.…”