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).
ABSTRACT
Light beams can carry orbital angular momentum (OAM) such that a helical phase front twists along the direction of propagation. OAM beams have been demonstrated in a wide variety of applications and have been found to offer a new orthogonal degree of freedom for multiplexing independent data streams for high-capacity point-to-point optical communications. However, to enable their efficient use in reconfigurable networks, approaches must be developed to manipulate OAM beams. We demonstrate OAM-based reconfigurable optical switching functions among multiple OAM beams. Selective data switching among three 100 Gb/s quadrature phase-shift keying OAM channels was achieved with a 2.1 dB optical signal-to-noise ratio penalty. The scheme of selective OAM-beam manipulation can be potentially cascaded to realize an arbitrary n×n switching function.
ABSTRACT
We demonstrate a tunable optical tapped delay line that can simultaneously and independently operate on multiple wavelength-division multiplexed (WDM) data signals. The system utilizes the wavelength-dependent speed of light, together with nonlinear wavelength conversion stages. A phase-preserving scheme enables coherent addition of the weighted taps. We reconfigured the system to perform separate simultaneous correlation (data pattern recognition), equalization, and modulation format conversion on four and eight WDM binary/quadrate phase-shift keyed channels at 26 and 20 Gbaud, respectively. The aggregate throughput of 416 Gb/s is achieved.
ABSTRACT
Fast reconstruction of the whole Brillouin gain spectrum is experimentally demonstrated using sweep-free Brillouin optical time-domain analysis (SF-BOTDA). Strain variations with the frequencies up to 400 Hz are spectrally analyzed, achieving strain sensitivity of 1 microstrain per root Hz at a sampling rate of 5.5 kHz and a spatial resolution of 4m. The results favorably compare with fiber Bragg grating sensing.
