Jerzy Siuzdak

Carrierless amplitude phase modulation of VCSEL with 4 bit/s/Hz spectral efficiency for use in WDM-PON

We experimentally demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs.

Binary-Phase Spatial Light Filters for Mode-Selective Excitation of Multimode Fibers

In this paper, spatial light modulation is proposed to increase the transmission capacity of graded-index multimode fibers. In the method, selected linearly polarized eigenmodes of the fiber are excited using simple binary-phase spatial filters. Numerical results indicate that the selectivity of the method is very high, also for fibers with perturbed profiles. The excess attenuation of the method is very low. In the experiment, a threefold increase of fiber bandwidth for several filters is obtained.

Compensation of a VLC Phosphorescent White LED Nonlinearity by Means of Volterra DFE

In this letter, a visible light communication link is analyzed that employs a white phosphorescent light emitting diode (LED) as transmitter and a p-i-n photodiode combined with optical filter as receiver. Four- and eight-level pulse amplitude modulation is used for data transmission. The link is not only limited by a rather small bandwidth of ~20 MHz of the LED, but also its nonlinearity becomes a problem when the modulation index exceeds ~60%. It is shown that a receiver with a decision feedback equalizer (DFE) with nonlinear Volterra feed-forward section up to the second order can efficiently compensate effects of nonlinearity of the transmitting LED and performs up to 5 dB better in terms of optical power than using a standard DFE.

Instability of the Multimode Fiber Frequency Response Beyond the Baseband for Coherent Sources

Fluctuations of the multimode fiber (MMF) frequency response beyond the baseband are observed experimentally when highly coherent light sources are used. This behavior is caused by the variation of the mode group powers caused by the relative modal phase fluctuation combined with spatial filtering at elements such as nonideal connectors. The observed effect may have vital influence on subcarrier multiplexing systems operation outside the baseband of the MMF. The effect is investigated both theoretically and experimentally.

RF Carrier Frequency Selection for Incoherent MIMO Transmission Over MM Fibers

In this paper, incoherent multiple-input multiple-output (MIMO) systems operating over multimode fiber are analyzed theoretically. In particular, investigated is the influence of selection of the RF carrier frequency and other system parameters on the value of SNR at the MIMO receiver. It is shown that the RF carrier frequency should be greater than the baseband (3 dB) frequency. Furthermore, it is proved that the MIMO channel SNR reduction is smaller if the mode groups used for communication between transmitter/receiver pairs are different.

Increasing multimode fiber transmission capacity by mode selective spatial light phase modulation

We propose spatial light modulation with binary phase filters to increase the transmission bandwidth of multimode fibers. In the experiment more than 300 % of bandwidth enhancement is obtained.

Experimental Comparison of PAM, CAP, and DMT Modulations in Phosphorescent White LED Transmission Link

In the paper, an experimental comparison of pulse amplitude, carrierless amplitude-phase, and discrete multitone modulations is carried in a visible light communications link employing white phosphorescent light-emitting diode (LED) as a transmitter. By changing the modulation index, the influence of LED nonlinearity on the performance is studied. The results indicate similar performance of pulse-amplitude modulation (PAM) and carrier-less amplitude-phase (CAP) (with a slight advantage of the former) and substantially worse performance of DMT.

A 2 and 3 channel mode group diversity multiplexing transmission over graded and step index multimode fibers

In this paper, operation of a cost-effective mode group diversity multiplexing system allowing 3 channel operation is demonstrated. Two different multiplexing/demultiplexing techniques are presented.

Transmission Beyond 100 Mbit/s Using LED Both as a Transmitter and Receiver

In this letter, the experimental operation of a wireless transmission link employing identical LEDs both as transmitter and receiver is demonstrated. The transmitted signal is a simple, two-level pulse amplitude modulation. Digital equalization at the receiver is applied to overcome the bandwidth limitation of the link. Transmission throughput exceeding 100 Mbit/s is reported, even if the receiving red LED operates in the photovoltaic mode.

Substantial OBI Noise Reduction in MM Fiber Network

Optical beat interference is one of the major problems impairing upstream transmission in passive optical networks. In this letter, a theoretical study indicates that if single mode fibers are replaced with multimode fibers, the interference is reduced at least by the factor of N, where N is the number of modes propagating. In the experiment carried with two types of lasers, a reduction of beating noise ~10 dB is observed. Even greater reduction is expected in the first transmission window.