Free-space coherent optical communication with orbital angular, momentum multiplexing/demultiplexing using a hybrid 3D photonic integrated circuit

Abstract

We demonstrate free-space space-division-multiplexing (SDM) with 15 orbital angular momentum (OAM) states using a three-dimensional (3D) photonic integrated circuit (PIC). The hybrid device consists of a silica planar lightwave circuit (PLC) coupled to a 3D waveguide circuit to multiplex/demultiplex OAM states. The low excess loss hybrid device is used in individual and two simultaneous OAM states multiplexing and demultiplexing link experiments with a 20 Gb/s, 1.67 b/s/Hz quadrature phase shift keyed (QPSK) signal, which shows error-free performance for 379,960 tested bits for all OAM states.

Ultrafast-laser-inscribed 3D integrated photonics: challenges and emerging applications

“…Also optical angular momentum (OAM) beams can be used for mode-division multiplexing [141]. This approach is in particular attractive for free-space optical communication with a recent demonstration of using a hybrid 3D photonic circuit for multiplexing and demultiplexing of different OAM beams [7].…”

“…However, all these concepts rely on bulk optics. An integrated optic OAM multiplexer and demultiplexer based on a hybrid photonic chip was demonstrated by Guan et al [7]. The device uses a silica planar lightwave circuit with a free propagation region to create a linear phase tilt across a linear array of 16 waveguides, as shown in Figure 11.…”

“…This capability has triggered a diverse range of applications in classical and nonclassical optics, waveguide and fibre lasers, telecommunications, astronomy, bio-photonics and sensing; appli- cations that capitalise on both 2D (single chip and hybrid) and, in particular, 3D (single chip and hybrid) device designs. Demonstrations of 3D photonic circuits include three-port couplers [4], 2D waveguide arrays [5], photonic lanterns [6], orbital angular momentum state generators [7] and quantum random walks [8]. With respect to a photon's higher degrees of freedom listed earlier, there have been reports of polarisation-encoded qubits [9], optical remapping and phase control aimed at stellar interferometry [10] and spatial mode conversion on a chip aimed at addressing future telecommunications needs [11], all of which exploit 3D photonic designs.…”

Software defined elastic optical networking in temporal, spectral, and spatial domains

“…14a correlation indicates that the BER of the supervisory channel can be used to estimate the BER of the data for different modulation formats, or to choose the modulation format that maximizes the spectral bandwidth while meeting the QoS requirement (or, data BER < 1E−4 in this case). The same spread-spectrum supervisory channel can be applied to each OAM state in the OAM-based SDM system to monitor the QoT of each single OAM state [31,44]. testbed, we have shown autonomous adaptation to network impairments to maintain QoT by utilizing the observeanalyze-act cycle facilitated by optical supervisory channel.…”

“…The compact design and single-mode interface easily connect with other high-speed optical components for future on-chip integration. The recent successful OAM transmission and switching experiments [26,27,31] exploited these 3D/2D PICs. We report below an example of OAM free space transmission exploiting the OAM PIC device described above.…”