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Ruben S. Luis

Publications and source records attributed to Ruben S. Luis.

11 recordsLinked to original sources
arXiv2026

Unlocking the O-Band Coherent Transmission: high-power, broadband soliton microcomb

The O-band (1260-1360 nm), located near the minimum chromatic dispersion of standard single-mode fiber, is an important transmission window for short-reach data-center interconnects. Its broader use is limited by the availability of scalable multi-wavelength, high-power and low-noise light sources. Here we demonstrate a high-power O-band soliton microcomb architecture combining an 834 GHz self-injection-locked (SIL) Si3N4 microcomb spanning 1050-1650 nm with a single-stage bismuth-doped phosphosilicate fiber amplifier. The system delivers > 0 dBm per carrier for 21 O-band comb lines over a 100 nm bandwidth, exhibiting low-noise operation and a 5 dB variation in amplifier gain. We validate the amplified source in a 25-km coherent WDM transmission experiment using 32-GBd dual-polarisation 64-QAM. Comb carriers spanning the O-band are characterised under simultaneous WDM loading, yielding an aggregate GMI-estimated throughput of 7.23 Tb/s and a post-FEC throughput of 6.94 Tb/s. This approach establishes a practical route towards broadband, high-power O-band microcomb sources for multi-terabit optical interconnects.

physics.optics↗
arXiv2026

One Terahertz Full-Field Digital Back-Propagation over 3000 km

We implement full-field digital back-propagation with a 1-THz receiver using 20 synchronous frequency-adjacent coherent receivers with digital stitching and a frequency-comb local oscillator. Relative to electronic dispersion compensation, per-channel DBP and full-field DBP achieve throughput gains of 2.2\% and 5.4\%, respectively.

eess.SP↗
arXiv2022

Real-time Transmission of Geometrically-shaped Signals using a Software-defined GPU-based Optical Receiver

A software-defined optical receiver is implemented on an off-the-shelf commercial graphics processing unit (GPU). The receiver provides real-time signal processing functionality to process 1 GBaud minimum phase (MP) 4-, 8-, 16-, 32-, 64-, 128-ary quadrature amplitude modulation (QAM) as well as geometrically shaped (GS) 8- and 128-QAM signals using Kramers-Kronig (KK) coherent detection. Experimental validation of this receiver over a 91~km field-deployed optical fiber link between two Tokyo locations is shown with detailed optical signal-to-noise ratio (OSNR) investigations. A net data rate of 5 Gbps using 64-QAM is demonstrated.

eess.SP↗
arXiv2021

Real-time 10,000 km Straight-line Transmission using a Software-defined GPU-Based Receiver

Real-time 10,000 km transmission over a straight-line link is achieved using a software-defined multi-modulation format receiver implemented on a commercial off-the-shelf general-purpose graphics processing unit (GPU). Minimum phase 1 GBaud 4-ary quadrature amplitude modulation (QAM) signals are transmitted over 10,000 km and successfully received after detection with a Kramers-Kronig (KK) coherent receiver. 8-, 16-, 32-, and 64-QAM are successfully transmitted over 7600, 5600, 3600, and 1600 km, respectively.

eess.SP↗
arXiv2021

Field Trial of a Flexible Real-time Software-defined GPU-based Optical Receiver

We introduce a flexible, software-defined real-time multi-modulation format receiver implemented on an off-the-shelf general-purpose graphics processing unit (GPU). The flexible receiver is able to process 2 GBaud 2-, 4-, 8-, and 16-ary pulse-amplitude modulation (PAM) signals as well as 1 GBaud 4-, 16- and 64-ary quadrature amplitude modulation (QAM) signals, with the latter detected using a Kramers-Kronig (KK) coherent receiver. Experimental performance evaluation is shown for back-to-back. In addition, by using the JGN high speed R&D network testbed, performance is evaluated after transmission over 91 km field-deployed optical fiber and reconfigurable optical add-drop multiplexers (ROADMs).

eess.SP↗
arXiv2020

Real-time, Software-Defined, GPU-Based Receiver Field Trial

We demonstrate stable real-time operation of a software-defined, GPU-based receiver over a metropolitan network. Massive parallelization is exploited for implementing direct-detection and coherent Kramers-Kronig detection in real time at 2 and 1 GBaud, respectively.

eess.SP↗
arXiv2018

Geometric Constellation Shaping for Fiber Optic Communication Systems via End-to-end Learning

In this paper, an unsupervised machine learning method for geometric constellation shaping is investigated. By embedding a differentiable fiber channel model within two neural networks, the learning algorithm is optimizing for a geometric constellation shape. The learned constellations yield improved performance to state-of-the-art geometrically shaped constellations, and include an implicit trade-off between amplification noise and nonlinear effects. Further, the method allows joint optimization of system parameters, such as the optimal launch power, simultaneously with the constellation shape. An experimental demonstration validates the findings. Improved performances are reported, up to 0.13 bit/4D in simulation and experimentally up to 0.12 bit/4D.

cs.IT↗