Characteristics of homogeneous multi-core fibers for SDM transmission

We describe optical data transmission systems using homogeneous, single-mode, multi-core fibers (MCFs). We first briefly discuss space-division multiplexing (SDM) fibers, observing that no individual SDM fiber offers overwhelming advantages over bundles of single-mode fiber (SMF) across all transmission regimes. We note that for early adoption of SDM fibers, uncoupled or weakly coupled fibers which are compatible with existing SDM infrastructure have a practical advantage. Yet, to be more attractive than parallel SMF, it is also necessary to demonstrate benefits beyond improved spatial spectral efficiency. It is hoped that the lower spread of propagation delays (skew) between spatial channels in some fibers can be exploited for improved performance and greater efficiency from hardware sharing and joint processing. However, whether these benefits can be practically harnessed and outweigh impairments or effort to mitigate cross talk between spatial channels is not yet clear. Hence, focusing on homogeneous MCFs, we first describe measurements and simulations on the impact of inter-core cross talk in such fibers before reporting experimental investigation into the spatial channel skew variation with a series of the experimental results including a comparison with SMF in varying environmental conditions. Finally, we present some system and transmission experiments using parallel recirculating loops that enable demonstration of both multi-dimensional modulation and joint digital processing techniques across three MCF cores. Both techniques lead to increased transmission reach but highlight the need for further experimental analysis to properly characterize the potential benefits of correlated propagation delays in such fibers

Spatial Pulse Position Modulation For Multi-Mode Transmission Systems

A spatial pulse position modulation is proposed and experimentally validated for a 12 spatial channel transmission over 53km multi-mode fiber. Improved data rates up to 30% are demonstrated with respect to conventional QPSK

Spatial Pulse Position Modulation For Multi-Mode Transmission Systems

A spatial pulse position modulation is proposed and experimentally validated for a 12 spatial channel transmission over 53km multi-mode fiber. Improved data rates up to 30% are demonstrated with respect to conventional QPSK

Turbulence-Resistant Free-Space Optical Communication Using Few-Mode Preamplified Receivers

We propose and demonstrate turbulence-resistant free-space optical communication using a 10-mode pre-amplified receiver. A 6-dB improvement over a single-mode preamplified receiver in power budget was achieved for a wavefront distortion of 4π across the receiving aperture

Dual-Core Fiber Interferometer For Sensing Applications

We introduce a novel dual-core fiber interferometer composed of a central coresurrounded by an external ring core. Results shows that this fiber interferometer can be used to makecost effective devices for sensing applications

10-Mode Photonic Lanterns Using Low-Index Micro-Structured Drilling Preforms

We demonstrate low mode-dependent loss 10-mode photonic lanterns using low-index micro-structured drilling preforms. The adiabaticity requirement for lantern tapering can be alleviated by the proposed solution leading to improved performances

10-Mode Photonic Lanterns Using Low-Index Micro-Structured Drilling Preforms

We demonstrate low mode-dependent loss 10-mode photonic lanterns using low-index micro-structured drilling preforms. The adiabaticity requirement for lantern tapering can be alleviated by the proposed solution leading to improved performances

Transverse Mode-Switchable Fiber Laser Based On A Photonic Lantern

We propose and experimentally demonstrate an intra-cavity transverse mode-switchable fiber laser based on a mode-selective photonic lantern and a few-mode Er-doped fiber amplifier. The six lowest-order LP modes can lase independently and are switchable by changing the input port of the photonic lantern. We measured the slope efficiency, mode intensity profile, and optical spectrum of each lasing mode. In addition, we demonstrate donut-shaped LP11 and LP21 modes using incoherent superposition and simultaneous lasing of the two degenerate modes

Erbium-Doped Fiber Amplifier For Oam Modes Using An Annular-Core Photonic Lantern

We experimentally demonstrated an erbium-doped fiber amplifier for OAM modes using an annular-core photonic lantern. The small signal gain for OAM modes with |L|=1 and 2 are obtained to be 22.1dB and 16.7dB