Showing papers on "Optical Carrier transmission rates published in 2022"

Transparent Optical-THz-Optical Link at 240/192 Gbit/s Over 5/115 m Enabled by Plasmonics

Abstract: A transparentOptical-subTHz-Optical link providing record-high single line rates of 240 Gbit/s and 192 Gbit/s on a single optical carrier over distances from 5 to 115 m is demonstrated. Besides a direct mapping of the optical to a 230 GHz subTHz-carrier frequency by means of a uni-traveling carrier (UTC) photodiode, we demonstrate direct conversion of data from the subTHz domain back to the optical domain by a plasmonic modulator. It is shown that the subTHz-to-optical upconversion can even be performed at good quality without any electrical amplifiers. Finally, at the receiver, the local oscillator is employed to directly map the optical signal back to the electrical baseband within a coherent receiver.

RF Self-Interference Cancellation and Frequency Downconversion With Immunity to Power Fading Based on Optoelectronic Oscillation

Abstract: We report a photonic approach to achieve simultaneous radio frequency (RF) self-interference cancellation (SIC) and frequency downconversion with immunity to power fading based on an optoelectronic oscillator (OEO) for an in-band full-duplex (IBFD) radio-over-fiber (ROF) system. A dual-drive Mach–Zehnder modulator (DDMZM) in a polarization-division multiplexing Mach–Zehnder modulator (PDM-MZM) is used to cancel the RF self-interference (SI) signal and generate optical carrier-suppressed double sidebands (CS-DSBs) of the signal of interest (SOI). Meanwhile, another DDMZM in the PDM-MZM is used to construct an OEO loop to generate optical CS-DSBs of the local oscillation (LO) signal. After detection at a photodetector (PD), a frequency downconverted signal is recovered with the RF self-interference cancellation (SIC). The proposed scheme can directly cancel the RF SI signal in the optical domain, meaning that it can overcome the limitation of SIC in the electrical domain. With the phase compensation introduced by a polarization controller, the desired signal is unaffected by the power fading over fiber transmission, which is significant for IBFD ROF systems. In addition, instead of an external microwave source, an OEO loop is used to generate an LO signal with a high spectral purity, which is very promising for integrated microwave photonics systems.

Bidirectional colorless WDM-PON RoF system with large spurious free dynamic range

Abstract: A bidirectional colorless wavelength-division-multiplexed passive optical network radio over fiber system with a large spurious-free dynamic range (SFDR) is proposed. By separating the unmodulated optical carrier from the polarization multiplexed optical signal in the optical network unit, upstream wavelength reuse is realized. By adjusting the angle and phase difference between the orthogonal optical polarization modes, third-order intermodulation distortion (IMD3) suppression of the downstream link is realized. The periodic power fading caused by dispersion in the system is solved through single sideband modulation. Experiments have verified the wavelength reuse effect of the upstream link. Compared with the traditional link based on a Mach–Zehnder modulator, the periodic power fading of the system is suppressed under different radio frequencies (RFs) and fiber lengths. The IMD3 of the downstream link is suppressed, and the SFDR is improved by more than 17 dB. Also, the proposed system is tested with a 16 quadrature amplitude modulation RF signal in the experiment, where a good adjacent channel power ratio and error vector magnitude of the system are obtained.

Broadband and High-Capacity Silicon Photonics Single-Sideband Modulator

Abstract: We propose a novel photonic-integrated single-sideband (SSB) modulator realized in silicon on insulator technology operating either in suppressed-carrier or full-carrier mode with continuously tunable carrier-to-sideband ratio (CSBR). Large rejection levels of the spurious sidebands and residual carrier in excess of 40 and 30 dB, respectively, with a CSBR tunability over a $\sim$ 50 dB range, are demonstrated. By employing a single silicon photonics (SiP) phase modulator and a compact and high-performance filtering element, the proposed architecture exhibits a compact layout and tolerates high driving voltage levels, leading to large OSNR values of the modulated sideband in excess of 50 dB. The device supports broadband RF data signals and its operation is tested with an up to 5 Gbps ASK-modulated carrier at 16.5 GHz, limited by available RF equipment. Furthermore, the technique allows to implement a frequency-multiplication mechanism for the input RF carrier, and up to threefold effective bandwidth enhancement of the SiP modulator is obtained by generating an optical SSB signal with a modulated spectral component spaced by 49.5 GHz from the optical carrier. Such features are promising for implementing cost-effective optical distribution of millimeter-wave wireless data signals supporting the evolution of next-generation radio access networks.

Filter-Less Photonic RF Image-Reject Mixing With Simultaneous Self-Interference Cancellation and Fiber Transmission

Abstract: A filter-free photonic method to simultaneously realize radio frequency (RF) image-reject mixing, self-interference cancellation (SIC), and fiber transmission for in-band full-duplex (IBFD) radio-over-fiber (RoF) link is reported. The key to achieving multi-functions is the joint manipulation of fiber dispersion-induced intermediate frequency (IF) amplitude and time delay changes, which is implemented by sideband phase-shifted optical carrier suppression (SPS-OCS) modulation and frequency tuning of the optical carrier. Owing to the control of IF amplitude and delay variation introduced by fiber dispersion, simultaneous deep image rejection and SIC over wide bandwidth can be realized after fiber transmission. Since no optical filter is required, the proposed system can work at a lower frequency, featuring a large frequency tuning range. For 25 km single-mode fiber (SMF) transmission, simultaneous 20 dB SIC within 1 GHz bandwidth and 29 dB image rejection ratio (IRR) at 6.6 GHz RF frequency in the C band, 21 dB SIC and 19 dB IRR within 1 GHz bandwidth in the X band, 24 dB SIC within 1 GHz bandwidth and 20 dB IRR at 16 GHz RF frequency in the Ku band are experimentally demonstrated. Furthermore, weak SOI with various modulation formats are well recovered after the cancellation of strong interference and fiber transmission.

Relative frequency response measurement of Mach-Zehnder modulators utilizing dual-carrier modulation and low-frequency detection.

Abstract: A self-calibrated approach is proposed to measure the relative frequency response of Mach-Zehnder modulators (MZMs) based on dual-carrier modulation and low-frequency detection. In this scheme, a dual-carrier is generated by combining a continuous-wave light from a distributed feedback laser diode with its frequency-shifted replica. Through modulating the dual-carrier by a frequency-scanned single-tone microwave signal via the MZM under test biased at its minimum transmission point, a fixed low-frequency heterodyne signal carrying the electro-optic modulation response information is generated after photodetection, from which the relative frequency response of the MZM can be obtained. In the experiment, the relative frequency response of a commercial MZM is measured by using the proposed method, where the result fits in with those obtained by using the conventional optical spectrum analysis method and the microwave network analysis method. The proposed method features self-calibration, high frequency resolution, low-frequency detection, and usage of only a single frequency-scanned microwave source, which is favorable for characterizing the microwave performance of MZMs in backbone optical communication and microwave photonic systems.

Photonic Techniques for Generating a Single RF Sideband With No Second Order Sidebands

Abstract: Two structures that can realise optical single sideband modulation without generating both second order upper and lower sidebands are presented. They are based on a dual-parallel Mach Zehnder modulator (DP-MZM) with an optical filter and a dual-polarisation dual-parallel Mach Zehnder modulator (DPol-DPMZM) with a 90° hybrid coupler. The former is an all-optical structure and hence it has a very wide bandwidth. The latter uses one DP-MZM to realise single sideband suppressed carrier modulation while the other DP-MZM simply passes the optical carrier. It also suppresses the third order sideband on the same side as the wanted fundamental RF modulation sideband. Hence, in an ideal situation, there is no second order harmonic component generated after photodetection. Experimental results are presented for the novel structures, which demonstrate the realisation of optical single sideband modulation without second order sidebands. The results also show large fundamental to second order harmonic power ratio over a wide input RF signal frequency range even after inserting a long single mode fibre into the system for signal transmission. The new optical single sideband modulators find applications in improving the multioctave spurious free dynamic range in a long-haul fibre optic link and reducing measurement errors in an optical vector analyser.

Photonic Generation of a Tunable Dual-Chirp Microwave Waveform

Abstract: A photonic-assisted tunable dual-chirp microwave waveform generator based on optical heterodyne detection is proposed and experimentally demonstrated. In the proposed scheme, a three-electrode distributed Bragg reflector laser diode (DBR-LD) is used to generate a broadband frequency-chirped optical pulse. A stable optical fiber laser and a Mach-Zehnder modulator (MZM) are used to perform a double-sideband suppressed carrier (DSB-SC) signal. The frequency difference between the two sidebands of the DSB-SC signal is larger than the frequency chirp range of the optical pulse. By tuning the center frequency of the optical pulse equals that of the DSB-SC signal and beating the optical pulse and the DSB-SC signal at a photodetector (PD), a dual-chirp microwave waveform is generated. The center frequency of the generated waveform is tuned by adjusting the modulated frequency of the DSB-SC signal. The tunability of the bandwidth and the temporal duration are achieved by tuning the optical pulse. Experimental results show that the center frequency, the bandwidth, and the temporal duration have tuning ranges from 7 to 13 GHz, 13 to 17 GHz, and 500 ns to 50 μs, respectively. Chirp rates up to ±26 GHz/μs for the up- and down-chirp waveforms are measured in the experimental demonstration, respectively. The demonstration shows new avenues to implement high-performance dual-chirp microwave waveform generators for applications in modern radar systems with improved range-Doppler resolution.

Radiation-Induced Transient Response Mechanisms in Photonic Waveguides

Abstract: A computationally efficient approach for estimating the impact of a 3-D distribution of carriers on an optical signal propagating within a waveguide is outlined and incorporated into a carrier transport solver to model the optical response as the carriers diffuse within the waveguide. It is shown that as the ionizing particle passes though the waveguide, the transmission will sharply drop, partially recover on the order of picoseconds, and then continue to recover as carriers recombine or escape the waveguide. The transient optical responses of a photonic waveguide can be incorporated into a photonic integrated circuit solver to demonstrate the spatial sensitivity of the radiation-induced transient optical response of a Mach–Zehnder modulator. The impact of the initial distribution of carriers injected into a photonic waveguide during single-event effects (SEEs) testing on the transient optical response is examined to assess the impact of using alternative SEE testing techniques to emulate ionizing particles. Since the transient optical response will depend on both the peak carrier density and total carriers injected into a waveguide, testing with larger carrier distributions will have difficultly matching both the transmission drop and recovery. Due to the reliance on carrier distributions with a larger spatial extent and fewer peak carrier densities than an ionizing particle, care must be taken when using alternative SEE testing techniques to not overestimate the SEE susceptibility of the photonic devices.

Photonic-enabled radio-frequency self-interference cancellation incorporated into an in-band full-duplex radio-over-fiber system

Abstract: A photonic approach for radio-frequency (RF) self-interference cancellation (SIC) incorporated in an in-band full-duplex radio-over-fiber system is proposed. A dual-polarization binary phase-shift keying modulator is used for dual-polarization multiplexing at the central office (CO). A local oscillator signal and an intermediate-frequency signal carrying the downlink data are single-sideband modulated on the two polarization directions of the modulator, respectively. The optical signal is then transmitted to the remote unit, where the optical signals in the two polarization directions are split into two parts. One part is detected to generate the up-converted downlink RF signal, and the other part is re-modulated by the uplink RF signal and the self-interference, which is then transmitted back to the CO for the signal down-conversion and SIC via the optical domain signal adjustment and balanced detection. The functions of SIC, frequency up-conversion, down-conversion, and fiber transmission with dispersion immunity are all incorporated in the system. An experiment is performed. Cancellation depths of more than 39 dB for the single-tone signal and more than 20 dB for the 20-MBaud 16 quadrature amplitude modulation signal are achieved in the back-to-back case. The performance of the system does not have a significant decline when a section of 4.1-km optical fiber is incorporated.

Single-modulator Based Multi-Format Switchable Signal Generator Without Background Noise

Abstract: A photonic multi-format background-free binarily modulated microwave signal generator using a single dual-polarization dual-parallel Mach–Zehnder modulator is proposed and demonstrated. The proposed generator features good reconfiguration and switchability. By simply adjusting the direct current biases of the modulator, amplitude shift keying (ASK), phase shift keying (PSK) and frequency-shift keying (FSK) microwave signals can be generated. Benefiting from the complementary intensity modulation, there is no residual baseband modulated signal in the generated binarily modulated signals. The system does not involve any optical or electrical filters, which ensures good tunability of the generator. By changing the frequency of the driven microwave carrier and bit rate of the electrical coded signal, the frequency and rate of the generated multi-format signals can be adjusted accordingly. The multi-format switchable signal generator has great potential in multi-functional communication and radar systems.

Generation of Single Sideband-Suppressed carrier (SSB-SC) Signal Based on Stimulated Brillouin Scattering

Abstract: A novel cost-effective wavelength shifter is suggested in this paper. This paper shows how to shift signals in the mm-wave area using a frequency shifter. Due to stimulated Brillouin scattering in optical fibre, the proposed approach produces a single sideband signal without the carrier signal. When compared to SSB-SC transmissions, the bandwidth efficiency of double sideband signals is lower. Because it employs an optical fibre with a performance degrading condition such as SBS as an application, the frequency shifter is entirely optical. The theory of Gain and Loss Spectrum of SBS within optical fibre is utilised to minimise the upshifted frequency component and boost the low shifter frequency component in order to generate improved carrier power and single sideband. The SBS phenomenon produces a single sideband, which is advantageous in advanced modulation systems and consumes less bandwidth. It’s worth noting that the SSB-SC signal may be generated using any optical approach, and the proposed work eliminates the need for non-optical components like 90-degree hybrid couplers. SSB-SC signals are capable of combating pulse broadening difficulties and have the ability to operate at terahertz frequencies. Transmission of an SSB-SC signal is also shown to validate the performance of the produced signal. Furthermore, the Q factor of SSB-SC, SSB with carrier, DSB-SC, and DSB with carrier signals is studied at various connection lengths.

Photonic Techniques for Generating a Single RF Sideband With No Second Order Sidebands

Abstract: Two structures that can realise optical single sideband modulation without generating both second order upper and lower sidebands are presented. They are based on a dual-parallel Mach Zehnder modulator (DP-MZM) with an optical filter and a dual-polarisation dual-parallel Mach Zehnder modulator (DPol-DPMZM) with a 90° hybrid coupler. The former is an all-optical structure and hence it has a very wide bandwidth. The latter uses one DP-MZM to realise single sideband suppressed carrier modulation while the other DP-MZM simply passes the optical carrier. It also suppresses the third order sideband on the same side as the wanted fundamental RF modulation sideband. Hence, in an ideal situation, there is no second order harmonic component generated after photodetection. Experimental results are presented for the novel structures, which demonstrate the realisation of optical single sideband modulation without second order sidebands. The results also show large fundamental to second order harmonic power ratio over a wide input RF signal frequency range even after inserting a long single mode fibre into the system for signal transmission. The new optical single sideband modulators find applications in improving the multioctave spurious free dynamic range in a long-haul fibre optic link and reducing measurement errors in an optical vector analyser.

Multi-access RF transfer with passive phase correction

Abstract: A multi-access RF transfer method with passive phase correction is proposed and demonstrated to achieve phase-stable RF signal distribution. First, a predistorted signal is generated from the probe RF signal and transmitted round-trip through a fiber link. Then, the probe signal and the pre-distorted signal modulate the orthogonally polarized components of an optical carrier, respectively, at a dual-polarization Mach-Zehnder modulator. The modulated signals are transferred to the remote nodes. The phase jitter of the fiber link can be eliminated by mixing the probe and pre-distorted signal in the electrical domain at each node. A proof-of-concept experiment is performed. A 5-GHz RF signal is successfully transmitted to two nodes with distances of 10 km and 15 km to the central office. The residual phase jitters are less than 1.09 ps (about 0.03 rad) and 1.59 ps (about 0.05 rad).

Dual-Output Microwave Photonic Frequency Up- and Down-Converter Using a 90° Optical Hybrid Without Filtering

Abstract: A dual-output microwave photonic frequency up- and down-converter using a 90° optical hybrid without filtering is proposed. By using a dual-parallel Mach-Zehnder modulator and a Mach-Zehnder modulator in parallel to realize carrier suppressed single sideband and carrier suppressed double sideband modulation, respectively, with a 90° optical hybrid and 90° electrical hybrid coupler, this scheme can implement two functions: simultaneous up- and down-conversion signal generation, or high image rejection in down-conversion. Simulation results show that the proposed structure can achieve an up-conversion with a tunable range of 17–23 GHz or a down-conversion with a tunable range of 1–7 GHz, respectively, based on a fixed 8 GHz LO signal. The unwanted signal suppression ratio of desired signal is about 27.2 dB for up-conversion and 30.0 dB for down-conversion. In addition, we have tested and analyzed the conversion gain, noise figure and spurs free dynamic range of the system. For image rejection in down-conversion, we can achieve an image rejection ratio (IRR) about 65.2 dB. Moreover, the impact of the phase drift, RF frequency, amplitude and phase variation on IRR is discussed. Finally, the influence of half-voltage imbalance of the DPMZM sub-modulators on IRR is analyzed, and a compensation method is given.

Pilot-Tone-Assisted Stimulated-Brillouin-Scattering-Based Optical Carrier Recovery for Kramers-Kronig Reception

Abstract: Optical carrier recovery provides a method to increase the carrier-to-signal power ratio at the receiver side of an optical communications system. Here, we propose to use optical carrier recovery based on stimulated Brillouin scattering to help overcome performance limits of Kramers-Kronig direct detection systems that arise due to the need for a high carrier-to-signal power ratio. By transmitting a low power pilot tone along with the signal, we simplify the stimulated Brillouin scattering based optical carrier recovery subsystem, toward better compatibility with the technology demands of short-reach systems. Experimental results show that after 80 km standard single mode fibre transmission, an 8.8 dB required optical signal-to-noise ratio improvement is achieved by the proposed optical carrier recovery subsystem, when compared with the standard Kramers-Kronig direct detection system. Moreover, we measure a receiver sensitivity enhancement of more than 2.8 dB in an optically pre-amplified receiver. These results indicate the potential of the proposed optical carrier recovery subsystem to improve reach or power requirements for Kramers-Kronig direct detection systems.

Filter-free photonics-assisted frequency translator with a tunable phase shift and amplitude based on an integrated DP-QPSK modulator.

Abstract: In this paper, we propose and demonstrate a novel, to the best of knowledge, filter-free photonics-assisted microwave frequency translator with a tunable phase shift and amplitude. The pivotal component of the proposed scheme is an integrated dual-polarization quadrature phase shift keying (DP-QPSK) modulator, which is applied to generate a polarization orthogonal carrier-suppressed single sideband modulation signal and frequency shifted optical carrier signal. The polarization-multiplexed optical signal outputs from the DP-QPSK modulator is then sent to a photodetector (PD) via a polarization controller (PC) and a polarizer to implement photoelectric conversion. The electrical signal output from the PD is the desired frequency translated microwave signal, and the amount of frequency shift is determined by the frequency of the sawtooth wave applied to the DP-QPSK modulator. In addition, since the PC can be used to adjust the polarization angle and introduce a phase difference between the two orthogonally polarized optical signals, the phase shift and amplitude of the obtained translated signal can also be easily tuned. A theoretical analysis and simulation experiment are carried out to verify the feasibility of the proposed scheme. The simulation results show that the novel scheme can realize frequency translation with a 360° continuously tunable phase shift and adjustable amplitude for both a single-tone signal and linearly frequency modulated signal with a 50 MHz bandwidth. The spurious suppression ratios of the single-tone signal and LFM signal after frequency translation are larger than 48 and 30 dB, respectively.

Single Sideband Suppressed Carrier Modulator for C-Band Multiple Access FSO Communication

Abstract: A Design procedure to realize a single sideband suppressed carrier (SSB-SC) modulator for free space optical (FSO) communication is theoretically presented. The operating principle relies on introducing spatiotemporal modulation into an indium-tin-oxide integrated plasmonic metasurface to obtain a time-varying output signal that is characterized by a sawtooth phase profile spanning on 2π and a constant amplitude. It is demonstrated that such spatiotemporal modulator transfers the incident signal into the first-order up-modulated sideband with more than 99% frequency conversion efficiency. The optical carrier suppression and undesired sideband rejection of 44 dB and 39 dB are calculated for the SSB-SC modulator, respectively. The application of the high-performance elements for multichannel multibeam scanning over a space-time shared-aperture platform is investigated. Thanks to the strong suppression of all undesired mixing products, the crosstalk between the channels with the same operating wavelength is significantly reduced.

Linearization of a dual-parallel Mach-Zehnder modulator using optical carrier band processing

Abstract: The linearization of a microwave photonic link based on a dual-parallel Mach-Zehnder modulator is theoretically described and experimentally demonstrated. Up to four different radio frequency tones are considered in the study, which allow us to provide a complete mathematical description of all third-order distortion terms that arise at the photodetector. Simulations show that a complete linearization is obtained by properly tuning the DC bias voltages and processing the optical carrier and. As a result, a suppression of 17 dBm is experimentally obtained for the third-order distortion terms, as well as a SDFR improvement of 3 dB. The proposed linearization method enables the simultaneous modulation of four different signals without the need of additional radio frequency components, which is desirable to its implementation in integrated optics and makes it suitable for several applications in microwave photonics.

A Microwave Photonics True-Time-Delay System Using Carrier Compensation Technique Based on Wavelength Division Multiplexing

Abstract: A novel microwave photonic true-time-delay (TTD) system using carrier compensation technology is proposed and experimentally demonstrated. Wavelength division multiplexing combines ten lasers into a single beam. We separate one channel from the laser as a compensating carrier, and the compensation carrier is combined with the time-delayed optical signals to be detected. Meanwhile, sideband signals are amplified effectively thanks to carrier-suppressed double-sideband (CS-DSB) modulation. Therefore, the power of both the central optical carriers and sidebands is guaranteed, which produces a better beat frequency result than the TTD system without carrier compensation. The simulation results confirm that the signal amplitude has an order of magnitude improvement due to the compensation. With employing the delay fibers based on multiple-fiber Bragg gratings (MFBGs), the experimental delay and response time reach 90.160 μs and 160.80 ns. The proposed technique can find applications in time-delay beamforming of phased array antennas (PAAs).

Generate high data rate of optical carries by using nanomaterial graphene in slab waveguide

Abstract: Abstract Single mode is one of the most practical applications in microwave propagations because of its high mode resolution and low transmission loss. In this paper, the single mode graphene material was implemented in slab waveguide to study the performance and optical properties of graphene material; the parameters that affect these models were found to be the cut-off frequency, attenuation wavenumbers, modes numbers, skin depth, angles incident, and propagation wave numbers. The effectiveness of these factors was simulated and analyzed using MATLAB software program. In this paper, the carriers were generated using nano-graphene; the optical carrier source provided seven carriers with the frequency spacing of 4.9682 GHz. After splitting the carriers using optical demultiplexer, these carriers were modulated independently using optical Quadrature phase shift keying (QPSK) modulators at symbol rate equal to 4.9682 Gsymbol/s; this matches the frequency spacing of the carriers. Under this argument, the total data rate was equal to 2*7*4.9682 Gsymbol/s = 69.5548 Gbit/s, and the total bandwidth was 34.774 GHz. These carriers were found to work in optical communication with high data rate.

High-speed Flexible Coherent Optical Transport Network

Abstract: In over 30 years, the optical transport network (OTN), the only physical network which actually carries the Internet data from the senders to the receivers, has experienced significant growth in both channel speed and link capacity. During the time period, the network has gone through several major upgrades as technology of optical transmission and networking continuously keeps advancing. In the middle of 1980s, early-stage fiber transmission system emerged as the first equipment for OTN ever introduced to network service providers, i.e., network carriers. The data rate on a pair of strands of fiber at that time was a few hundred Mbps for the system typically [1]. In the later 1980s, synchronous optical network (SONET as an example) began to play its role in carriers’ transport networks [2]. SONET systems provided several hundred Mbps capacity per channel at the beginning and quickly moved to supply 10 Gbps per channel (OC-192) in the middle of the 1990s. Then, 40-Gbps channel (OC-768) was introduced to further increase channel capacity. As the required optical channel capacity became even larger when entering the new century, a new OTN standard, OTN, was introduced in the early 2000s. The new standard includes channels with capacities of 2.5 Gbps (OTU1), 10 Gbps (OTU2), 40 Gbps (OTU3), 100 Gbps (OTU4), and beyond [3, 4].

High-Resolution Microwave Frequency Measurement Based on Optical Frequency Comb and Image Rejection Photonics Channelized Receiver

Abstract: A high-resolution microwave signal frequency measurement scheme based on optical frequency comb (OFC) and an image rejection microwave photonics channelized receiver is proposed. The scheme consists of two branches. The OFC is generated by cascaded Mach-Zehnder modulators (MZMs) in the upper branch. The optical carrier is frequency shifted by the optical frequency shifter (OFS) in the lower branch. The shifted optical carrier is sent to polarization modulator (PolM) to be modulated by the RF signal to be measured. The signal from the upper and lower branches are injected into 90-degree optical hybrid and divided into four outputs. The optical signal of each output is divided into channels by the wavelength division multiplexer (WDM) and beat by the balance photodetector (BPD). The back-end of the scheme adopts image rejection down-conversion method to prevent spectral aliasing in the measurement process. Simulation verifies the effectiveness of this scheme. The results show that the scheme can accurately measure microwave signals within the frequency range of 1-79 GHz.

Stimulated-Brillouin-scattering-based arbitrarily phase coded microwave waveform transmitter with anti-dispersion transmission

Abstract: Sha Zhu (朱 厦), Kunpeng Zhai (翟鲲鹏), Wei Li (李 伟), and Ning Hua Zhu (祝宁华) 1 College of Microelectronics, Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China 2 State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China 3 School of Electronic, Electrical and Communication Engineering, Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China

RF over fiber system for 5G application

Abstract: 5G communications involve the transfer of several Gb/s information in their small cells. The main solutions for high-speed data transfers for this objective are millimeter-wave RF signals. It is difficult to produce these high-frequency RF signals on the electrical field, so more study is given to the photonic generation of these signals. In this study, the utilization of a dual-drive Mach – Zehnder Modulator (DD-MZM) illustrates a special optical millimeter-wave(MMW) generation. A new method for producing a local oscillator frequency quadrupling optical carrier suppression (OCS) MMW signal utilize two equivalent DD-MZMs based on this form is shown. Data flow on a Radio over Fiber (RoF) network for transmission and generation of a 2.5 Gbps downlink, at OSSR (Optical Sideband Suppression Ratio) of up to 32 dB is acquired by simulation. The Radio Frequency Spurious Suppression Ratio (RFSSRR) is 22 dB