Abu Sahmah Mohd. Supa'at

All-Optical OFDM Generation for IEEE802.11a Based on Soliton Carriers Using Microring Resonators

The optical carrier generation is the basic building block to implement all-optical orthogonal frequency-division multiplexing (OFDM) transmission. One method to optically generate single and multicarriers is to use the microring resonator (MRR). The MRRs can be used as filter devices, where generation of high-frequency (GHz) soliton signals as single and multicarriers can be performed using suitable system parameters. Here, the optical soliton in a nonlinear fiber MRR system is analyzed, using a modified add/drop system known as a Panda ring resonator connected to an add/drop system. In order to set up a transmission system, i.e., IEEE802.11a, first, 64 uniform optical carriers were generated and separated by a splitter and modulated; afterward, the spectra of the modulated optical subcarriers are overlapped, which results one optical OFDM channel band. The quadrature amplitude modulation (QAM) and 16-QAM are used for modulating the subcarriers. The generated OFDM signal is multiplexed with a single-carrier soliton and transmitted through the single-mode fiber (SMF). After photodetection, the radio frequency (RF) signal was propagated. On the receiver side, the RF signal was optically modulated and processed. The results show the generation of 64 multicarriers evenly spaced in the range from 54.09 to 55.01 GHz, where demodulation of these signals is performed, and the performance of the system is analyzed.

W-Band OFDM Transmission for Radio-Over-Fiber Link Using Solitonic Millimeter Wave Generated by MRR

A system comprises of a W-band (75-110 GHz) optical millimeter (mm)-wave generation using microring resonators (MRRs) and radio-over-fiber (RoF) link architectures is presented for multigigabit data rates demand. The MRRs are used to generate optical mm-wave soliton pulses for W-band applications. To achieve faster transmission speed wirelessly, higher spectral efficiency (SE) and better transmission performance, orthogonal frequency-division multiplexing (OFDM) is used. The results show that the MRRs support W-band optical soliton pulses, which can be used in an OFDM transmission/receiver system. Localized narrow bandwidth soliton pulses within frequencies of 92.2-93.2 GHz can be seen in the throughput port of the Panda system with respect to the full width at half maximum and free spectrum range of 3.5 and 184 MHz, respectively. The error vector magnitude of the system was measured and the viability of the solitonic OFDM-based system for RoF link over 25-Km fiber link and 2-m wireless link was confirmed. The data rate of the system with 16-quadrature amplitude modulation is measured as 43.6 Gb/s and with 10 GHz of bandwidth, the SE is obtained as 4.36 bit/s/Hz.

MMI-MZI Polymer Thermo-Optic Switch With a High Refractive Index Contrast

The 2 x 2 MMI-MZI polymer thermo-optic switch in a high refractive index contrast (0.102) with a new structure design is realized. The fabrication was done using standard fabrication techniques such as coating, photolithography, and dry etching. A crosstalk level of dB has been achieved. Meanwhile, the extinction ratio of 28.6 dB has been achieved in this device. The polarization-dependent loss of 0.3 dB was measured at 1550 nm wavelength. In terms of wavelength dependency, the device shows a good performance within C-band wavelength with vacillation of the insertion loss value around 0.88 dB. The power consumption of 1.85 mW was measured to change the state of the switch from the cross to bar state. The measured switching time was 0.7 ms.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul.

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated.

Recent development on time and wavelength-division multiplexed passive optical network (TWDM-PON) for next-generation passive optical network stage 2 (NG-PON2)

The second stage of next-generation passive optical network (NG-PON2) based on time and wavelength division multiplexed passive optical network (TWDM-PON) was proposed by a telecommunication group research to enhance the performance of broadband access networks. TWDM-PON was selected as the best candidate for NG-PON2 solution because of its ability to support the NG-PON2 requirements, such as enhanced bandwidth capacity, 40Gb/s, and coexistence with previously existing generations without any change to optical distribution network (ODN). This paper reviewed the recent progress carried out on a TWDM-PON system configuration, with emphasis on tunable transmitter and receiver optical network unit (ONU) in terms of the amount of tuning range reported in exploiting the wavelength plan provided with cost efficiency. The speed of data rate transmitted on the downstream and upstream links between optical line terminal (OLT) and ONU with the way of stacking approach in NG-PON2 is reviewed. In addition, the power system budget is reviewed to determine the number of users allocated with the system with each transmission allowed.

W-Band OFDM for Radio-over-Fiber Direct-Detection Link Enabled by Frequency Nonupling Optical Up-Conversion

A system involving W-band (75-110 GHz) optical millimeter (mm)-wave generation using the external optical modulator (EOM) in a radio-over-fiber (RoF) link is presented for satisfying the requirements for multi-gigabit-per-second data rates. A 90-GHz mm-wave signal was generated by a nonupling (nine times) increase in only a 10-GHz local oscillator by biasing the EOM at its zero level and choosing an appropriate modulation index. To achieve a fast transmission speed wirelessly, high spectral efficiency (SE), and better transmission performance, orthogonal frequency-division multiplexing (OFDM) is used. The bit error rate (BER) and error vector magnitude (EVM) of the system were measured for three different fiber lengths and for a wireless distance of 1-5 m. The results show that the system with the SE of ~4 (b/s)/Hz and 16-ary quadrature amplitude modulation (QAM) 40-GB/s OFDM signals can be received by the end user with BER less than 3.8 × 10-3 and EVM less than 25% over a 50-km optical fiber and 3-m wireless link.

All-Optical Generation of Two IEEE802.11n Signals for 2

A radio-over-fiber system capable of very spectrally efficient data transmission and based on multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) is presented here. Carrier generation is the basic building block for implementation of OFDM transmission, and multicarriers can be generated using the microring resonator (MRR) system. A series of MRRs incorporated with an add/drop filter system was utilized to generate multicarriers in the 193.00999-193.01001-THz range, which were used to all-optically generate two MIMO wireless local area network radio frequency (RF) signals suitable for the IEEE802.11n standard communication systems, and single wavelengths at frequencies of 193.08, 193.1, and 193.12 THz with free spectral range of 20 GHz used to optically transport the separated MIMO signals over a single-mode fiber (SMF). The error vector magnitude (EVM) and bit error rate of the overall system performance are discussed. Results show that the generated RF signals wirelessly propagated through the MIMO channel using the 2 × 2 MIMO Tx antennas. There is an acceptable EVM variation for wireless distance lower than 70, 30, and 15 m. It can be concluded that the transmission of both MIMO RF signals is feasible for up to a 50-km SMF path length and a wireless distance of 15 m.

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Using the micro-ring resonator (MRR) system, the single and multi-carriers at frequencies of f(1)=192.898, f(2)=192.990, f(3)=193.1, f(4)=193.315, and f(5)=193.537  THz with a free spectral range (FSR) of 92, 110, 215, and 222 GHz, respectively, are generated to be suitable for a radio-over-fiber (RoF) system based on multi-input multi-output (MIMO) with orthogonal frequency division multiplexing (OFDM). Demonstrated are the concepts of all-optical MIMO signal generation and its transmission over a 50 km single mode fiber (SMF) optical link and an up to 3 m wireless link. Sixty-four multi-carriers are used in the all-optical generation of three MIMO W-Band RF signals, where the single carriers (f(3)-f(5)) transport the signals over the RoF link. The bit error rate (BER) of the overall system performance is discussed; thus, the transmission of MIMO signals is feasible for up to an SMF path 50 km long and a wireless distance of 3 m.

2 MIMO-RoF via MRR System

This paper describes a demonstration of soliton transmission over fiber-wireless (Fi-Wi) networks using mode-locked stable solitons over a 50-km-long fiber and a short-distance wireless link. Ultrashort optical pulse sources in the 1.5-μm region are seen as increasingly important for achieving ultrahigh-speed optical transmission and signal processing at optical nodes. Mode-locked solitons were generated by a simple ring laser cavity incorporating a very thin layer of carbon nanotube (CNT), together with an erbium-doped fiber (EDF) laser used as an active bulk gain medium. Experimental measurements involved the transmission of the generated mode-locked soliton over a 50-km-long single-mode fiber (SMF), and a radio-frequency (RF) spectrum subsequently generated was a result of beating frequency of wavelengths launched into the photodetector at the other end of the SMF. This RF spectrum array was in the range of WiFi frequencies. System performance was evaluated by first selecting one of the RF carriers centered at 2.5 GHz via an RF bandpass filter and subsequently using this carrier to transmit quadrature phase-shift keying (QPSK) and 16-quadrature amplitude modulation (16-QAM) data signals. The described optical circuit, containing an EDF laser, a CNT, an SMF, and a wireless link, was shown to achieve ultrastable transmission of mode-locked soliton over a long-distance Fi-Wi network.

Generation and transmission of 3 × 3 w-band multi-input multi-output orthogonal frequency division multiplexing-radio-over-fiber signals using micro-ring resonators

Optical communications systems have evolved from lengthy fibers to powerful wireless system. This has hence resulted in the use of optical wireless communication system in space communications. As the number of satellites orbiting Earth increase year by year, a network between the satellites provides a method for them to communicate with each other. This is important for satellites to send information to one another and also to relay the information from one satellite to another satellite and then to the ground stations. By using laser satellite communication, the satellites can be connected with data rates up to several Gbps. The paper will present the optical wireless communication (IsOWC) link performance focusing on data transfer between Low Earth Orbit satellites. The system performance including bit rates, input power, wavelength and distance on an inter-satellite link were analyzed.