BER Measurements Research Articles

Scaling comb-driven resonator-based DWDM silicon photonic links to multi-Tb/s in the multi-FSR regime

The use of chip-based micro-resonator Kerr frequency combs in conjunction with dense wavelength-division multiplexing (DWDM) enables massively parallel intensity-modulated direct-detection data transmission with low energy consumption. Resonator-based modulators and filters used in such systems can limit the number of usable wavelength channels due to practical constraints on the maximum achievable free spectral range (FSR). In this work, we introduce the design of multi-Tb/s comb-driven resonator-based silicon photonic links by leveraging the multi-FSR regime. We demonstrate the viability of the link architecture with yield estimates that are supported by extensive wafer-scale measurements of 704 micro-resonators fabricated in a commercial complementary metal–oxide–semiconductor foundry. We show that a 2.80 Tb/s link is realizable with a ≥6σ yield (∼99.999%), and that aggregate bandwidths of 3.76 Tb/s and 4.72 Tb/s are possible if yield targets are relaxed (3σ and 1σ, respectively). All designs represent a 1.94−3.28× boost to aggregate link bandwidth while maintaining BER≤10−10 performance, with a theoretical bandwidth of 10.51 Tb/s being possible for sufficiently robust resonators. We use high-speed BER measurements to inform co-optimization of data rate and aggressor spacing (λag), limiting any additional loss-based power penalties to off-resonance insertion loss (IL) and routing loss. This work demonstrates that, through the multi-FSR regime, there is a clear path toward Kerr comb-driven ultra-broadband, high bandwidth silicon photonic links that can support next-generation data centers and high-performance computers.

Optimize BER Offset QPSK Baseband Modulation-Demodulation featuring AWGN and OFDM

<p class="Abstract">In communication system, being fastest not always the best option because of much great error probabilities. Complex architecture also cost high for the component maintenances. An optimal OQPSK modem is provide for friendly use and affordable model in academic purposes. The proposed method is moderate way with twice data size than the conventional method, but error calculation is exactly constant. Good and optimal BER measurements from simulated binary data useful for academic learning purpose. <em></em></p>

Proof-of-Concept of the Time and Spectral Optical Aggregation Network

In this article, we present the proof of concept (PoC) of the time and spectral optical aggregation (TISA) approach that allows a better filling of the time and spectral resources of an optical transport network. Some innovative solutions have been implemented, such as a new and fast tunable laser that permits to color the bursts sent in the TISA network, as well as their transmission with both DP-QPSK and DP-16QAM coherent multi-band (MB) OFDM formats. BER versus OSNR measurements have been achieved showing less than 1-dB penalty in back-to-back or after transmission. The tolerance of bursts against frequency mismatch occurring between the transceiver and the optical filter that extracts a sub-band inside the MB-OFDM signal has also been evaluated, and ∼1.5 GHz tolerance has been measured for bursts of ∼6.7 GHz bandwidth. Furthermore, in order to mitigate the transients in the coherent receiver that faces alternatively the presence or absence of signal, a novel channel estimator based on a sliding window has been introduced. Its efficiency and performance has been experimentally validated, and its ability to suppress the error threshold of the BER versus OSNR curves has been demonstrated. By the experimental proof of concept delivered here, the ability of the TISA network to perform with a good level of performance the transparent routing and sub-wavelength aggregation/disaggregation in the time and spectral domains simultaneously has been established. Beyond the important and crucial aspect of the optimal filling of the optical resources, our PoC demonstrate the ability of the TISA approach to push the flexibility of an optical transport network at its limit while allowing a cost and power consumption limitation obtained by the removal of costly and power-hungry optical-electrical-optical regenerators.

25.6 Tbps Capacity and Sub-µsec Latency Switching for DataCenters Using >1000-Port Optical Packet Switch Architectures

We discuss the challenges and limitations of current electrical DataCenter switches towards scaling beyond the 25.6 Tb/s capacity-era while meeting a low-latency and high-radix envelope. With the high-power SerDes and required DSP interfaces forming critical scaling factors, we discuss the perspectives and challenges of migrating to Optical Packet Switch (OPS) technologies for avoiding the electronically-induced bottlenecks, while exploiting reliable and practical techniques for overcoming well-known OPS problems, like buffering and high-port connectivity. We demonstrate the feasibility of OPS schemes by reporting experimental results of our Hipoλaos architecture towards extending its line-rate to 25 Gb/s per port and enabling 25.6 Tb/s switch capacities through a 1024-radix layout, while still preserving sub-μs latency metrics. Experimental results are presented for both unicast and multicast packets, employing the 1024-radix Hipoλaos architecture in a fully-fledged FPGA-controlled switching Plane, along with a 32 × 32 Arrayed Waveguide Grating Router (AWGR) device. The unicast performance is validated through BER measurements, while optical multicasting to 5 nodes is also experimentally evaluated at 25 Gb/s, along with an evaluation of the broadband multicast capabilities of the switch. Moreover, a mixed-traffic scenario involving both unicast and multicast traffic is demonstrated. Finally, a discussion about the perspectives and challenges of bringing OPS in DC networks is presented.

Random weather phenomena in free-space optical - FTTx communication system

In the last few decades, optical wireless communication became an essential technology in various applications. Researchers have paid more attention to achieving high bandwidth and low loss. However, the random weather phenomena cause attenuation of optical signals, thus will decrease the bandwidth in optical wireless communication. In this article, we investigate a hybrid free-space optical (FSO) and fiber-to-the-x (FTTx) communications link based on wavelength-division multiple access (WDMA) over different random weather phenomena that operate over different wavelengths. The performance of the hybrid FSO-FTTx system is evaluated under clear sky weather phenomena, heavy rain weather phenomena, and heavy haze weather phenomena based on BER and Q-Factor measurements. The results show that we can transmit 140 Gbit/s data over 9650 meters a hybrid link under the clear sky and heavy rain weather phenomena, 3950 meters over. Additionally, the transmission of 140 Gbit/s data can be achieved for 1450 meters under the heavy haze weather phenomenon.

All-Optical Wavelength Conversion in an InP Photonic Integrated Turbo-Switch

We experimentally demonstrate all-optical wavelength conversion of 56 Gb/s non-return-to-zero (NRZ) signals in an Indium Phosphide (InP) photonic integrated circuit implementing a turbo-switch. The circuit consists of two cascaded semiconductor optical amplifiers (SOAs) with a bandpass filter in between. In this configuration, cross gain modulation (XGM) between a modulated input signal and a continuous wave (CW) light in the first SOA allows to generate a wavelength converted copy of the input signal, while the second SOA, fed by the probe signal selected by the filter, ensures a fast gain recovery. Operations in down- and up-conversion are shown by ER and BER measurements, demonstrating the effectiveness of the photonic integrated circuit (PIC).

Integrated Optical Add-Drop Multiplexer in SOI Based on Mode Selection and Bragg Reflection

We present a compact optical add-drop multiplexer in silicon-on-insulator based on combining mode selection with Bragg reflection. The add-drop channel has a 3-dB bandwidth of 2 nm, an extinction ratio of 30 dB, and an interferometric crosstalk of less than –42 dB. We characterize the inter-channel and interferometric crosstalk performance using BER measurements for 10-Gb/s NRZ data and obtain crosstalk induced power penalties less than 3.5 dB.

Design and Implementation a BPSK Modem and BER Measurement in AWGN Channel

Design and Implementation a BPSK Modem and BER Measurement in AWGN Channel

Desain dan Realisasi Sistem Komunikasi Cahaya Tampak untuk Streaming Teks berbasis PWM

The design and implementation of visible light communication systems for transmitting digital data (texts) have been discussed in this paper. Then, two evaluations were performed also, i.e. the demonstration of streaming text through the visible light as a proof-of-concept system design. The next evaluation is a BER measurement intended to know the VLC system performance quantitatively. The value of BER against the several parameters: by the variation of distance and its reception angle. The proposed VLC system works well until the photodiode reception angle to the LEDs up to 50°. According to evaluation, our system can operate optimally within 30 – 80 cm or 50 – 130 cm of optical channel range depending on the Gain setting option. To support the reliability of noise from ambient light and interference lamps such as fluorescent lamps, the filters circuit are employed: high pass filter and DC-offset remover. Based on the BER analysis, the filters can compensate the problem of ambient light noise (DC-offset signal) and interference lamp (100-150 Hz of carrier frequency). The speed of data-rate obtained with 1-PWM modulation and the low-cost analog component is 3.3 kbps.

In Situ Measurement of Acoustic Filters on RF Transceiver Modules

In cellular communications certain frequency bands are licensed to specific applications guaranteeing predictability and reliability of service quality. Undesirable interference from these bands have to be removed by high-quality passive filters. This paper introduces a novel measurement method to determine the frequency response of a cellular system related to these passive filters. The method is based on in situ BER measurements and does not require access to the components of the transceiver hardware or knowledge about components and implementation. It is nondestructive and can be applied as in situ measurement of any wireless modem during normal operation. The results are successfully verified against direct S -parameter measurements of the SMT components.

Sub‐carrier channel demultiplexing of THz‐wave OFDM signal assisted by optical technology

A real-time processing method for demultiplexing a high-speed terahertz (THz)-wave OFDM signal is proposed and demonstrated. An electrical signal, which is down-converted from the THz-wave OFDM signal, is up-converted into an optical OFDM signal through an optical modulator. Then, the generated optical OFDM signal is demultiplexed into sub-carrier channels in the optical domain by utilising an integrated-optic OFDM demultiplexer with discrete Fourier transform function. The processing principle of the method and some preliminary experimental results including BER measurement to demonstrate the effectiveness of the method are reported. A 2 × 10 Gbit/s THz-wave OFDM signal was demultiplexed into sub-carrier channels with the method as preliminary investigation.

Review on design and measurement of ber of faded qpsk modulated system

Review on design and measurement of ber of faded qpsk modulated system

Design and measurement of ber of faded qpsk modulated system

Design and measurement of ber of faded qpsk modulated system

All-optical 4x10 Gbps NAND gate using single mode Fabry-Pérot laser diode.

We demonstrate all-optical 4x10 Gbps NAND gate with an individual input data rate of 10 Gbps using single mode Fabry-Pérot laser diode. The proposed scheme is based on the principle of multi-input injection locking. All-optical NAND gate is one of the universal logic gates which can be used for realizing all other logic gates for optical communication and networks. The output performance of the proposed all-optical multi-input NAND gate is verified with output spectrum domain results, waveforms, rising-falling time, and eye diagram measurement at 10 Gbps input. The ON/OFF contrast ratio of 41 dB is measured at the spectrum domain output when all four input beams are logic high. In all other combinations of four inputs, maximum ON/OFF contrast ratio of 1.5 dB ON/OFF is measured. Clear output waveform, output eye diagram with an extinction ratio of about 11 dB, and rising-falling time of about 35 ps are obtained. The BER measurement is carried out and we found the power penalty of about 1.7 dB at BER of 10(-9).

BER evaluation of a low-crosstalk silicon integrated multi-microring network-on-chip.

The operation of an integrated silicon-photonics multi-microring network-on-chip (NoC) is experimentally demonstrated in terms of transmission spectra and bit error rates at 10 Gb/s. The integrated NoC consists of 8 thermally tuned microrings coupled to a central ring. The switching functionalities are tested with concurrent transmissions at both the same and different wavelengths. Experimental results validate the analytical model based on the transfer matrix method. BER measurements show performance up to 10(-9) at 10 Gb/s with limited crosstalk and penalty (below 0.5 dB) induced by an interfering transmission.

Scalable In-Band Optical Notch-Filter Labeling for Ultrahigh Bit Rate Optical Packet Switching

We propose a scalable in-band optical notch-filter labeling scheme for optical packet switching of high-bit-rate data packets. A detailed characterization of the notch-filter labeling scheme and its effect on the quality of the data packet is carried out in simulation and verified by experimental demonstrations. The scheme is able to generate more than 91 different labels that can be applied to 640-Gb/s optical time division multiplexed packets causing an eye opening penalty of $<$ 1.2-dB. Experimental demonstration shows that up to 256 packets can be uniquely labeled by employing up to eight notch filters with only 0.9-dB power penalty to achieve BER of 1E-9. Using the proposed labeling scheme, optical packet switching of 640 Gb/s data packets is experimentally demonstrated in which two data packets are labeled by making none and one spectral hole using a notch filter and are switched using a LiNbO $_3$ switch. The performance of the two data packets before/after switching is investigated by BER measurements and all 256 data channels achieve BER 1E-9 at the expense of only 4.1-dB total system penalty.

Photonic generation for multichannel THz wireless communication.

We experimentally demonstrate photonic generation of a multichannel THz wireless signal at carrier frequency 200 GHz, with data rate up to 75 Gbps in QPSK modulation format, using an optical heterodyne technique and digital coherent detection. BER measurements were carried out for three subcarriers each modulated with 5 Gbaud QPSK or for two subcarriers modulated with 10 Gbaud QPSK, giving a total speed of 30 Gbps or 40 Gbps, respectively. The system evaluation was also performed with three subcarriers modulated with 12.5 Gbaud QPSK (75 Gbps total) without and with 40 km fibre transmission. The proposed system enhances the capacity of high-speed THz wireless transmission by using spectrally efficient modulated subcarriers spaced at the baud rate. This approach increases the overall transmission capacity and reduces the bandwidth requirement for electronic devices.

GNUradio and 802.11: performance evaluation and limitations

In the last few years, software defined radio has become a widespread tool for research and development in the wireless arena. One of the drivers of this success is GnuRadio, an open source collection of signal processing routines, together with the inception of commercially available software radio front-ends to complete the signal chain. A number of wireless protocols have been developed on top of Gnu- Radio, including the ubiquitous 802.11 standard. In this article, we focus on the use and performance evaluation of the 802.11 BBN software-based transmitter and receiver implementation, highlighting its capabilities and limitations. In order to achieve this, we analyze the BER and packet error rate measurements on a reference scenario.

25 Gb/s transmission over 820 m of MMF using a multimode launch from an integrated silicon photonics transceiver

A new high bandwidth bend-insensitive MMF optimized for 1310 nm is designed and characterized. 25 Gb/s transmission over a record 820 m length using a multimode launch from an integrated SiPh transceiver at 1310 nm through the new fiber is demonstrated with a power penalty of 3.4 dB at 10(-12) BER. Detailed characteristics of the fiber and transceiver are presented along with BER measurements.

PPLN-based OOK and DQPSK optical grooming by amplitude and phase-signal multiplexing through pump depletion

We propose and characterize a simple, integrable, and wavelength-preserving scheme able to groom a 40Gbps (D)QPSK signal with a 20Gbps OOK one into a 20Gbaud (60Gbps) 8-APSK signal. The proposed all-optical scheme is based on the second-order nonlinear signal-depletion effect in a single periodically poled lithium niobate (PPLN) waveguide. Performance of the device, characterized by means of BER measurements, attests error-free operation and a power penalty below 4.1dB.