Abstract

We experimentally utilize a tunable, broadband pixel-array-based integrated receiver for recovering orbital-angular-momentum (OAM) multiplexed channels. The OAM receiver comprises a pixel-array-based mode converter, four phase controllers, and a pixel-array-based 4-to-3 coupler. Utilizing the mode converter, a free-space data-carrying OAM beam ( $\ell \ = \ - 1$ or $\ell \ = \ + 1$ ) is vertically coupled into four waveguides. The resulting waveguide modes carry an OAM-order-dependent phase delay between each other. Subsequently, a 4-to-3 coupler coherently combines four waveguide inputs with the specific phase delay into a specific output port. By further tuning the relative phase delay of the waveguides using the phase controllers, the data channel carried by a specific OAM beam ( $\ell \ = \ - 1$ or $\ell \ = \ + 1$ )) could be routed to different ports. As there is no specific resonant wavelength, the OAM receiver could be operated with a relatively broad bandwidth. The experimental results show that: (a) the target OAM mode to be received by the OAM receiver could be tuned from ( $\ell \ = \ - 1$ to $\ell \ = \ + 1$ ) with a <−14-dB inter-modal power coupling; (b) in a wavelength range of ∼6 nm, two OAM-carried 50-Gbaud quadrature-phase-shift-keying (QPSK) data channels ( $\ell \ = \ - 1$ and $\ell \ = \ + 1$ ) could be recovered by the tunable OAM receiver with a bit error rate (BER) performance below the 7% forward error correction threshold; and (c) a 400-Gbit/s OAM-multiplexed and wavelength-division-multiplexed (WDM) QPSK link is demonstrated with a <2-dB optical signal-to-noise ratio (OSNR) penalty compared to that of a single-beam link.

Demonstration of generating a 100 Gbit/s orbital-angular-momentum beam with a tunable mode order over a range of wavelengths using an integrated broadband pixel-array structure

Hao Song, Huibin Zhou, Kaiheng Zou, Runzhou Zhang, Kai Pang, Haoqian Song, Amir Minoofar, Xinzhou Su, Nanzhe Hu, Cong Liu, Robert Bock, Shlomo Zach, Moshe Tur, and Alan E. Willner
Opt. Lett. 46(19) 4765-4768 (2021)

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

Binbin Guan, Ryan P. Scott, Chuan Qin, Nicolas K. Fontaine, Tiehui Su, Carlo Ferrari, Mark Cappuzzo, Fred Klemens, Bob Keller, Mark Earnshaw, and S. J. B. Yoo
Opt. Express 22(1) 145-156 (2014)

Demonstration of free space coherent optical communication using integrated silicon photonic orbital angular momentum devices

Tiehui Su, Ryan P. Scott, Stevan S. Djordjevic, Nicolas K. Fontaine, David J. Geisler, Xinran Cai, and S. J. B. Yoo
Opt. Express 20(9) 9396-9402 (2012)

Utilizing phase delays of an integrated pixel-array structure to generate orbital-angular-momentum beams with tunable orders and a broad bandwidth

Hao Song, Zhe Zhao, Runzhou Zhang, Haoqian Song, Huibin Zhou, Kai Pang, Jing Du, Long Li, Cong Liu, Xinzhou Su, Ahmed Almaiman, Robert Bock, Moshe Tur, and Alan E. Willner
Opt. Lett. 45(15) 4144-4147 (2020)

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

Hao Huang, Guodong Xie, Yan Yan, Nisar Ahmed, Yongxiong Ren, Yang Yue, Dvora Rogawski, Moshe J. Willner, Baris I. Erkmen, Kevin M. Birnbaum, Samuel J. Dolinar, Martin P. J. Lavery, Miles J. Padgett, Moshe Tur, and Alan E. Willner
Opt. Lett. 39(2) 197-200 (2014)