Roger Delbue

Mode-multiplexed 6×20-GBd QPSK transmission over 1200-km DGD-compensated few-mode fiber

Low differential group delay (DGD) between the modes of a graded-index few-mode fiber is obtained by combining segments with DGD of opposite sign. Transmission of mode-multiplexed 6×20-GBd QPSK over a record distance of 1200 km is demonstrated.

Low-loss mode coupler for mode-multiplexed transmission in few-mode fiber

We present a novel low-loss 3-spot mode coupler to selectively address 6 spatial and polarization modes of a few-mode fiber. The coupler is used in a 6×6 MIMO-transmission experiment over a 154-km hybrid span consisting of 129-km depressed-cladding and 25-km graded-index few-mode fiber.

12 x 12 MIMO Transmission over 130-km Few-Mode Fiber

We demonstrate 12 x 12 multiple-input multiple-output mode multiplexed transmission over130-km of few-mode fiber of a combined 6-space-, 2-polarization-, and 8-wavelength-division multiplex, using low-loss photonic lantern and 3D-waveguide mode multiplexers.

Mode-Multiplexed Transmission Over a 209-km DGD-Compensated Hybrid Few-Mode Fiber Span

We transmitted five wavelength channels and six spatial and polarization modes over a 209-km-long hybrid few-mode fiber span. The fiber supports six spatial and polarization modes, and consists of a first section of large effective area depressed-cladding few-mode fiber followed by a graded-index few-mode fiber. The differential group delay is compensated by using fiber spools with differential group delay of opposite sign. Low-loss three-spot mode couplers are used to couple to the few-mode fiber, and backward pumped-distributed Raman amplification is used to overcome the fiber loss. The 40-Gb/s QPSK signals with an aggregate capacity of 1.2 Tb/s are recovered by coherent multiple-input-multiple-output off-line digital signal processing. The impulse response at various span lengths is compared and analyzed in detail.

All-ETDM 80-Gbaud (160-Gb/s) QPSK Generation and Coherent Detection

A single-polarization 160-Gb/s (80-Gbaud) electronically time-division-multiplexed (ETDM) quadrature phase-shift-keyed (QPSK) signal is generated and coherently detected using two 45-GHz-bandwidth oscilloscope prototypes and offline processing.

All-ETDM 80-Gbaud (640-Gb/s) PDM 16-QAM Generation and Coherent Detection

A single-carrier 640-Gb/s polarization-division multiplexed 16-ary quadrature amplitude modulation signal is generated using electronic multiplexing to 80 Gbaud. Coherent detection and off-line signal processing equalize the limited bandwidth of the transmit and receive hardware.

Technologies for very high bandwidth real-time oscilloscopes

Technologies and design considerations are presented for the design of very high bandwidth oscilloscopes. These include chip, DSP and microwave technologies employed in some of the fastest waveform digitizers in the world.

Combined SDM and WDM transmission over 700-km Few-Mode Fiber

We experimentally demonstrate multiple-input multiple-output transmission over a 700-km few-mode fiber of a combined 3-space-, 2-polarization-, and 34-wavelength-division multiplex, using low-loss 3-spot mode couplers.

160-Gbaud coherent receiver based on 100-GHz bandwidth, 240-GS/s analog-to-digital conversion

We demonstrate a coherent receiver using a 100-GHz electrical bandwidth and 240-GS/s real-time oscilloscope as analog-to-digital converter in a 160-Gbaud QPSK system.