Rafael Puerta

Effective 100 Gb/s IM/DD 850-nm Multi- and Single-Mode VCSEL Transmission Through OM4 MMF

To cope with the ever increasing data traffic demands in modern data centers, new approaches and technologies must be explored. Short range optical data links play a key role in this scenario, enabling very high speed data rate links. Recently, great research efforts are being made to improve the performance of vertical-cavity surface-emitting lasers (VCSELs) based transmission links, which constitute a cost-effective solution desirable for massive deployments. In this paper, we experimentally demonstrate intensity-modulation direct-detection transmissions with a data rate of 107.5 Gb/s over 10 m of OM4 multimode fiber (MMF) using a multimode VCSEL at 850 nm, and up to 100 m of OM4 MMF using a single-mode VCSEL at 850 nm. Measured bit error rates were below 7% overhead forward error correction limit of 3.8e−03, thus, achieving an effective bit rate of 100.5 Gb/s. These successful transmissions were achieved by means of the multiband approach of carrierless amplitude phase modulation.

Capacity enhancement for hybrid fiber-wireless channels with 46.8Gbit/s wireless multi-CAP transmission over 50m at W-band

Transmission of a 46.8 Gbit/s multi-band cap signal is experimentally demonstrated over a 50 m W-band radio-over-fiber link. Bit error rates below 3.8×10⁻³ are achieved, employing nine cap bands with bit and power loading.

Up to 35 Gbps ultra-wideband wireless data transmission links

For the first time Ultra-Wideband record data transmission rates up to 35.1 Gbps and 21.6 Gbps are achieved, compliant with the restrictions on the effective radiated power established by both the United States Federal Communications Commission and the European Electronic Communications Committee, respectively. To achieve these record bit rates, the multi-band approach of Carrierless Amplitude Phase modulation scheme was employed. Wireless transmissions were achieved with a BER below the 7% overhead FEC threshold of 3.810−3.

Photonic downconversion and optically controlled reconfigurable antennas in mm-waves wireless networks

We report on optically controlled antennas and photonic downconversion for mm-wave wireless communication applications. Experimental results demonstrate a transmission of 1.25 Gb/s using 28 and 38GHz frequency bands.

Adaptive MultiCAP modulation for short range VCSEL based transmissions

We propose an adaptive approach for multi-band carrierless amplitude/phase modulation, with advantages of adaptive bit rate and energy savings. Successful performance is demonstrated on 850 nm multi-mode VCSEL based transmissions achieving up to 40.6 Gb/s.

Optically generated single side-band radio-over-fiber transmission of 60Gbit/s over 50m at W-band

60Gbit/s single side-band multi-band cap radio-over-fiber transmission at W-band is demonstrated. A spectral efficiency of 3.8bit/s/Hz and bit error rates below 3.8×10⁻³ are achieved after 50m wireless transmission.

Short-range links beyond 100Gb/s with vertical-cavity surface-emitting lasers

Global data traffic is increasing at an unprecedented rate. This increase is due in large part to the rise of cloud computing services, multimedia web applications, and Internet-of-Things technologies. Indeed, the bandwidth requirements imposed by these applications are expected to double network traffic in data centers within five years.1 To cope with these demands, the viability of using new photonics technologies and approaches to improve the performance (i.e., to increase the capacity and reduce the latency) of data-center interconnects must be explored. Furthermore, these new approaches must ensure a reduced carbon footprint and lower operating costs.2 A large amount of research has recently been carried out on vertical-cavity surface-emitting lasers (VCSELs) with the aim of meeting these requirements. VCSELs represent one of the most appealing technologies for application to optical interconnects because of the advantages that they provide (e.g., low power consumption, reduced fabrication cost, the feasibility of on-wafer testing, and high coupling efficiencies).3 Additionally, the rapid development of electronics has led to the increased efficacy of advanced modulation techniques over larger bandwidths, thereby significantly increasing the spectral efficiency of communications systems. Combining these new photonics technologies with advanced modulation formats has enabled the development of single-polarization and single-wavelength intensity modulation/direct detection (IM/DD) high-speed links. A number of recent research efforts have achieved effective bitrates of close to 100Gb/s using VCSELs. Specifically, effective bitrates Figure 1. Chip wafer of single-mode vertical-cavity surface-emitting lasers (VCSELs), shown together with a fiber-optic pigtail test probe.7

Nonorthogonal multiple access and carrierless amplitude phase modulation for flexible multiuser provisioning in 5G mobile networks

In this paper, a combined nonorthogonal multiple access (NOMA) and multiband carrierless amplitude phase modulation (multiCAP) scheme is proposed for capacity enhancement of and flexible resource provisioning in 5G mobile networks. The proposed scheme is experimentally evaluated over a W-band millimeter wave radio-over fiber system. The evaluated NOMA-CAP system consists of six 1.25-GHz multiCAP bands and two NOMA levels with quadrature phase-shift keying and can provide an aggregated transmission rate of 30 Gbit/s. The proposed system can dynamically adapt to different user densities and data rate requirements. Bit error rate performance is evaluated in two scenarios: a low user density scenario where the system capacity is evenly split between two users and a high user density scenario where NOMA and multiCAP are combined to serve up to 12 users with an assigned data rate of 2.5 Gbit/s each. The proposed system demonstrates how NOMA-CAP allows flexible resource provisioning and can adapt data rates depending on user density and requirements.

Minimization of Crosstalk in Multicore Optical Fibre Link using Real-time FPGA-based Approach

We experimentally demonstrate pre-emphasis based performance for a 2 km long 7-core multicore fiber link. Simultaneous transmission below the FEC threshold is achievable for all cores by using signal equalization in a FPGA.

10Gb/s ultra-wideband wireless transmission based on multi-band carrierless amplitude phase modulation

In this paper, for the first time, a record UWB transmission of 10Gb/s is experimentally demonstrated employing a multi-band approach of carrierless amplitude phase modulation (MultiCAP). The proposed solution complies with the restrictions on the effective radiated power established by both the United States Federal Communications Commission and the European Electronic Communications Committee, achieving a BER below the limit for a 7% overhead FEC of 3.8 · 10-3 up to respective wireless distances of 3.5m and 2m.