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

Opt Express. 2012 Apr 23;20(9):9396-402. doi: 10.1364/OE.20.009396.


We propose and demonstrate silicon photonic integrated circuits (PICs) for free-space spatial-division-multiplexing (SDM) optical transmission with multiplexed orbital angular momentum (OAM) states over a topological charge range of -2 to +2. The silicon PIC fabricated using a CMOS-compatible process exploits tunable-phase arrayed waveguides with vertical grating couplers to achieve space division multiplexing and demultiplexing. The experimental results utilizing two silicon PICs achieve SDM mux/demux bit-error-rate performance for 1‑b/s/Hz, 10-Gb/s binary phase shifted keying (BPSK) data and 2-b/s/Hz, 20-Gb/s quadrature phase shifted keying (QPSK) data for individual and two simultaneous OAM states.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Equipment Design
  • Equipment Failure Analysis
  • Semiconductors*
  • Signal Processing, Computer-Assisted / instrumentation*
  • Silicon / chemistry*
  • Surface Plasmon Resonance / instrumentation*
  • Systems Integration
  • Telecommunications / instrumentation*


  • Silicon