100  Tbit/s free-space data link enabled by three-dimensional multiplexing of orbital angular momentum, polarization, and wavelength

Abstract

We investigate the orthogonality of orbital angular momentum (OAM) with other multiplexing domains and present a free-space data link that uniquely combines OAM-, polarization-, and wavelength-division multiplexing. Specifically, we demonstrate the multiplexing/demultiplexing of 1008 data channels carried on 12 OAM beams, 2 polarizations, and 42 wavelengths. Each channel is encoded with 100 Gbit/s quadrature phase-shift keying data, providing an aggregate capacity of 100.8 Tbit/s (12×2×42×100 Gbit/s).

Orbital-Angular-Momentum Polarization Mode Dispersion in Optical Fibers

“…Equation (4) then can be extended to higher orders: 01 and TM 01 modes. When |l|=0, Equation (7) converges to (5). On the Poincaré sphere described by (7), the North Pole is always RCP and the south Pole is always LCP.…”

“…The orthogonal OAM mode set provides a new degree of freedom to increase the optical communication capacity in addition to other freedoms that have already been widely used such as the wavelength, time and polarization [2]. OAM-division multiplexing have been demonstrated in both optical free-space [3]- [5] and fiber optic communications [6].…”

Massive individual orbital angular momentum channels for multiplexing enabled by Dammann gratings

“…For visualization purposes, we also measured the constellations of the QPSK signals from the demultiplexed OAM beams. Figure 3e1 and 3e2 shows the constellations of the OAM channels '53 and '5221 at a BER of 5310 24 . The similarity of the two figures proves that the performances of the different OAM channels are similar.…”

“…13 Recently, the same research group achieved a data capacity of 100 Tbit s 21 through 1008 channels by multiplexing 42 wavelengths, 12 OAM beams and two polarization states together. 24 However, in all the pioneering work described above, the maximum number of OAM channels that carried independent signals was only four, which is mainly constrained by the sophisticated experimental set-up required to detect multiple collinear OAM beams in parallel. Parallel detection of massive OAM channels is one of the major challenges in OAM-based optical communications.…”

Optical Orbital Angular Momentum Demultiplexing and Channel Equalization by Using Equalizing Dammann Vortex Grating

“…In 2010, Awaji et al first applies the OAM multiplex technology into optical communication [11]. In addition, in 2014, Huang et al fuse OAM multiplexing together with PDM and WDM technology achieved 100 T bits/s transmission rate in free space optical communication [13]. One of the most important issues for OAM optical multiplex communication system is looking for a highly efficient multiplexing/demultiplexing method to realize the space separation of different OAM states and achieve the channel equalization among different OAM channels.…”