Long-Range Fiber Transmission of Optical Vortices

We use specialty fiber (“vortex fiber”), to create and propagate orbital angular momentum states over ~kilometer lengths in telecom band (~1550nm). The spiral phase structure of the vortex beams was confirmed by interference with a Gaussian reference. This result is an important step toward achieving long-range classical and quantum communication links using orbital angular momentum of light.DARPA Grant No. HR0011-11-1-000

Measurement of the spin-orbit coupling interaction in ring-core optical fibers

Ring-core optical fibers have been designed to carry orbital angular momentum modes. We demonstrate the imaging of these modes, individually identifying modes separated temporally by only 30 ps. A single-pixel camera operating in the short-wave infrared detection range is used to image the 1550 nm wavelength optical modes. With this technique, examination of these optical modes can be performed with significantly higher temporal resolution than is possible with conventional imaging systems, such that the imaging of modes separated by spin-orbit coupling is achieved and evaluated. Deconvolution is required to separate the instrument response from the optical mode signal, increasing the clarity and temporal resolution of the measurement system

Dynamically tunable optical bottles from an optical fiber

Optical fibers have long been used to impose spatial coherence to shape free-space optical beams. Recent work has shown that one can use higher order fiber modes to create more exotic beam profiles. We experimentally generate optical bottles from Talbot imaging in the coherent superposition of two fiber modes excited with long period grat-ings, and obtain a 28 μm × 6 μm bottle with controlled contrast up to 10.13 dB. Our geometry allows for phase tuning of one mode with respect to the other, which enables us to dynamically move the bottle in free space. © 201

Observation of Interaction of Spin and Intrinsic Orbital Angular Momentum of Light

Interaction of spin and intrinsic orbital angular momentum of light is observed, as evidenced by length-dependent rotations of both spatial patterns and optical polarization in a cylindrically-symmetric isotropic optical fiber. Such rotations occur in straight few-mode fiber when superpositions of two modes with parallel and anti-parallel orientation of spin and intrinsic orbital angular momentum (IOAM=$2\hslash$) are excited, resulting from a degeneracy splitting of the propagation constants of the modes.Comment: 6 pages, 5 figures, and a detailed supplement. Version 3 corrects a typo and adds the journal referenc