Showing papers on "Optical Carrier transmission rates published in 2015"

Counting the cycles of light using a self-referenced optical microresonator

Abstract: Phase coherently linking optical-to-radio frequencies with femtosecond mode-locked laser frequency combs has enabled counting the cycles of light and is the basis of optical clocks, absolute frequency synthesis, tests of fundamental physics, and improved spectroscopy. Using an optical microresonator frequency comb to establish a coherent link between optical and microwave frequencies will extend optical frequency synthesis and measurements to areas requiring compact form factor, on-chip integration, and comb line spacing in the microwave regime, including coherent telecommunications, astrophysical spectrometer calibration, or microwave photonics. Here we demonstrate a microwave-to-optical link with a microresonator. By using a temporal dissipative single soliton state in an ultrahigh-Q crystalline microresonator that is broadened in highly nonlinear fiber, an optical frequency comb is generated that is self-referenced, allowing us to phase coherently link a 190 THz optical carrier directly to a 14 GHz microwave frequency. Our work demonstrates that precision optical frequency measurements can be realized with compact high-Q microresonators.

Dual-Chirp Microwave Waveform Generation Using a Dual-Parallel Mach-Zehnder Modulator

Abstract: A photonic approach to generating a dual-chirp microwave waveform using a single dual-parallel Mach-Zehnder modulator (DPMZM) is proposed and experimentally demonstrated. A dual-chirp microwave waveform can be used in a radar system to improve its range-Doppler resolution. In the proposed approach, a baseband single-chirp waveform is applied to one sub-Mach-Zehnder modulator (sub-MZM) in the DPMZM and a microwave carrier is applied to the other sub-MZM. By biasing the two sub-MZMs at the minimum transmission point to suppress the optical carrier, a dual-chirp microwave waveform with a central frequency upconverted to the frequency of the microwave carrier is generated. A theoretical analysis is performed, which is then verified by a proof-of-concept experiment. A dual-chirp microwave waveform at 6 GHz with a tunable bandwidth at 200 MHz and 2 GHz is generated.

39-GHz Millimeter-Wave Carrier Generation in Dual-Mode Colorless Laser Diode for OFDM-MMWoF Transmission

Abstract: By using a nully biased MZM to modulate an incoming single-mode light into a double sideband (CCA-DSB or CCS-DSB) master with preserved or suppressed central carrier, the directly OFDM encoded dual-mode colorless laser diode is performed for a successful fusion between wired and wireless links to establish a 5G-based MMWoF system. The dual-mode L-band optical carrier successfully delivers a 36-Gb/s OFDM data with a BER of $3.2 \times 10^{-3}$ , while the stabilized 39-GHz mm-wave carrier can provide wireless 4-Gb/s 16-QAM OFDM data with 16.6-dB SNR. The in-situ 39-GHz mm-wave carrier can be synthesized by optically heterodyne mixing the dual-mode carrier at remote node. When injection-locking with the CCS-DSB master, the dual-mode slave colorless laser diode improves its central carrier suppression ratio and RIN to 38 dB and −104 dBc/Hz, respectively. In comparison, the dual-DFBLD master injection-locking mixed mm-wave carrier is relatively unstable due to the individual DFBLDs at free-running condition. With the CCS-DSB master, the mm-wave carrier self-beat from the dual-mode optical carrier exhibits a narrow linewidth of <3 kHz with high purity and stability. Such a dual-mode colorless laser diode-based MMWoF link is capable of fusing the fiber wired and the 5G wireless links demanded in the near future.

Wideband Doppler frequency shift measurement and direction ambiguity resolution using optical frequency shift and optical heterodyning

Abstract: A photonic approach for both wideband Doppler frequency shift (DFS) measurement and direction ambiguity resolution is proposed and experimentally demonstrated. In the proposed approach, a light wave from a laser diode is split into two paths. In one path, the DFS information is converted into an optical sideband close to the optical carrier by using two cascaded electro-optic modulators, while in the other path, the optical carrier is up-shifted by a specific value (e.g., from several MHz to hundreds of MHz) using an optical-frequency shift module. Then the optical signals from the two paths are combined and detected by a low-speed photodetector (PD), generating a low-frequency electronic signal. Through a subtraction between the specific optical frequency shift and the measured frequency of the low-frequency signal, the value of DFS is estimated from the derived absolute value, and the direction ambiguity is resolved from the derived sign (i.e., + or -). In the proof-of-concept experiments, DFSs from -90 to 90 kHz are successfully estimated for microwave signals at 10, 15, and 20 GHz, where the estimation errors are lower than ±60 Hz. The estimation errors can be further reduced via the use of a more stable optical frequency shift module.

Multicore-Fiber-Enabled WSDM Optical Access Network With Centralized Carrier Delivery and RSOA-Based Adaptive Modulation

Abstract: We proposed and experimentally demonstrated a wavelength-space division multiplexing (WSDM) optical access network architecture with centralized optical carrier delivery utilizing multicore fibers (MCFs) and adaptive modulation based on reflective semiconductor amplifier (RSOA). In our experiment, five of the outer cores are used for undirectional downstream (DS) transmission only, whereas the remaining outer core is utilized as a dedicated channel to transmit upstream (US) signals. Optical carriers for US are delivered from the optical line terminal (OLT) to the optical network unit (ONU) via the inner core and then transmitted back to the OLT after amplification and modulation by the RSOA in the colorless ONU side. The mobile backhaul (MB) service is also supported by the inner core. Wavelengths used in US transmission should be different from that of the MB in order to avoid the Rayleigh backscattering effect in bidirectional transmission. With quadrature phase-shift keying--orthogonal frequency-division multiplexing (QPSK-OFDM) modulation format, the aggregation DS capacity reaches 250 Gb/s using five outer cores and ten wavelengths, and it can be further scaled to 1 Tb/s using 20 wavelengths modulated with 16 QAM-OFDM. For US transmission, 2.5 Gb/s QPSK-OFDM transmission can be achieved just using a low-bandwidth RSOA, and adaptive modulation is applied to the RSOA to further enhance the US data rate to 3.12 Gb/s. As an emulation of high-speed MB transmission, 48 Gb/s in-phase and quadrature (IQ) modulated popularization division multiplexing (PDM)-QPSK signal is transmitted in the inner core of MCF and coherently detected in the OLT side. Both DS and US optical signals exhibit acceptable performance with sufficient power budget.

Experimental demonstration of a statistical OFDM-PON with multiband ONUs and elastic bandwidth allocation [invited]

Abstract: The statistical orthogonal frequency division multiplexing passive optical network (OFDM-PON) concept with multiband optical network units (ONUs) is experimentally tested with two users and an optical line terminal at 2.5/5 Gb/s total effective capacity with binary phase-shift keying (BPSK)/quadrature phase-shift keying (QPSK) modulation. Both downstream and uplink were measured based on intensity modulation and direct detection. The ONUs consisted oflocal nonpreselected wavelength distributed feedback laser sources centrally controlled to reduce overlapping probability. In addition, a radio-frequency mixing stage in the ONUs up/downconverts the user data to/from the OFDM signal, reducing the computational effort. Compared with ONUs processing the whole signal, the multiband approach presents comparable results with almost symmetrical power budgets of around 25 and 20 dB with BPSK and QPSK, respectively, which could increase up to 4.5 dB by allocating a spectral guard interval between the optical carrier and the OFDM data. Furthermore, elastic bandwidth allocation is explored, which is shown to compensate for up to 18 dB differential link loss.

Spectrally-Efficient 400-Gb/s Single Carrier Transport Over 7 200 km

Abstract: Since the advent of wavelength division multiplexed optical systems, increasing the bit rate per optical carrier has proved to be the most effective method to drive the overall cost of optical systems down. However, multicarrier approaches have gained momentum for 400-Gb/s transport to cope with bandwidth limitations of optoelectronic components. In this paper, single carrier modulated 400-Gb/s transport over transatlantic distances is demonstrated for the first time. Using high-speed digital-to-analog converters, we successfully generated a 64 GBaud dual-polarization signal modulated using 16-ary quadrature amplitude modulation. Thanks to Nyquist pulse shaping, our channels are closely packed with 66.7 and 75 GHz channel spacing, resulting on 6 and 5.33-bit/s/Hz of spectral efficiencies, respectively. Transceiver design is based on an optimization procedure of inter-symbol interference mitigation and forward error correction overhead. A spatially-coupled low density parity check code with decoder-aware degree optimization is used to reduce the gap to capacity. We validated our transceiver design by transporting five channels over 6 600 and 7 200-km with 6 and 5.33-bit/s/Hz of spectral efficiency, respectively. We analyze as well the performance gain provided by non-linear mitigation using filtered digital back-propagation algorithm.

All-optical tuning of a nonlinear silicon microring assisted microwave photonic filter: theory and experiment.

Abstract: We propose and demonstrate an all-optical tuning mechanism to tune the response of a microwave photonic filter (MPF) based on a nonlinear silicon microring resonator (MRR). The tuning mechanism relies on the optical nonlinearities induced resonant wavelength shift in the silicon MRR, leading to the change of frequency difference between the optical carrier frequency and resonant frequency of the silicon MRR. A detailed theoretical model is established to describe the operation of the proposed all-optical tunable MPF. Two cases are studied in the experiment, i.e. the optical carrier frequency is located at the left or right side of the MRR resonant frequency. Both forward and backward pumping configurations in each case are demonstrated. Using the fabricated silicon MRR and exploiting light to control light, the central frequency of the notch MPF can be flexibly tuned by adjusting the pump light power. Moreover, the presented all-optical tuning mechanism might also facilitate interesting applications such as microwave switching and microwave modulation.

Optical injection locking-based amplification in phase-coherent transfer of optical frequencies

Abstract: We demonstrate the use of an optical injection phase locked loop (OIPLL) as a regenerative amplifier for optical frequency transfer applications. The optical injection locking provides high gain within a narrow bandwidth (<100 MHz) and is capable of preserving the fractional frequency stability of the incoming carrier to better than 10(-18) at 1000 s. The OIPLL was tested in the field as a mid-span amplifier for the transfer of an ultrastable optical carrier, stabilized to an optical frequency standard, over a 292 km long installed dark fiber link. The transferred frequency at the remote end reached a fractional frequency instability of less than 1×10(-19) at averaging time of 3200 s.

Effect of soil temperature on optical frequency transfer through unidirectional dense-wavelength-division-multiplexing fiber-optic links.

Abstract: Results of optical frequency transfer over a carrier-grade dense-wavelength-division-multiplexing (DWDM) optical fiber network are presented. The relation between soil temperature changes on a buried optical fiber and frequency changes of an optical carrier through the fiber is modeled. Soil temperatures, measured at various depths by the Royal Netherlands Meteorology Institute (KNMI) are compared with observed frequency variations through this model. A comparison of a nine-day record of optical frequency measurements through the 2×298 km fiber link with soil temperature data shows qualitative agreement. A soil temperature model is used to predict the link stability over longer periods (days-months-years). We show that optical frequency dissemination is sufficiently stable to distribute and compare, e.g., rubidium frequency standards over standard DWDM optical fiber networks using unidirectional fibers.

Accurate optical vector network analyzer based on optical single-sideband modulation and balanced photodetection

Abstract: A novel optical vector network analyzer (OVNA) based on optical single-sideband (OSSB) modulation and balanced photodetection is proposed and experimentally demonstrated, which can eliminate the measurement error induced by the high-order sidebands in the OSSB signal. According to the analytical model of the conventional OSSB-based OVNA, if the optical carrier in the OSSB signal is fully suppressed, the measurement result is exactly the high-order-sideband-induced measurement error. By splitting the OSSB signal after the optical device-under-test (ODUT) into two paths, removing the optical carrier in one path, and then detecting the two signals in the two paths using a balanced photodetector (BPD), high-order-sideband-induced measurement error can be ideally eliminated. As a result, accurate responses of the ODUT can be achieved without complex post-signal processing. A proof-of-concept experiment is carried out. The magnitude and phase responses of a fiber Bragg grating (FBG) measured by the proposed OVNA with different modulation indices are superimposed, showing that the high-order-sideband-induced measurement error is effectively removed.

Analysis of System Imperfections in a Photonics-Assisted Instantaneous Frequency Measurement Receiver Based on a Dual-Sideband Suppressed-Carrier Modulation

Abstract: Instantaneous frequency measurement receivers are a well-established technology that is used for the ultrafast characterization of pulsed microwave signals over a broad bandwidth. Recently, numerous photonic approaches to instantaneous frequency measurement (IFM) have been proposed and experimentally demonstrated, with the ultimate aim of leveraging the benefits of optical technology to improve the performance of already existent electronic solutions. Despite the numerous results, not so much attention has been paid so far to understand the subtle implications that system imperfections can have on realistic photonics-based IFM receivers. Here, we focus our attention on one of the most promising among these IFM techniques, which is based on optical power monitoring of a dual-sideband suppressed-carrier modulation after a Mach–Zehnder interferometer (MZI) filter. We develop a time-domain model for the rigorous analysis of all major optical and electrical effects, including amplitude imbalance and phase errors in the modulator and the MZI, as well as on-pulse RF phase/frequency modulation. Simulations are then used to illustrate the substantial effect that a nonperfectly suppressed optical carrier can have on system performance. More importantly, it is shown that in a nonideal situation, the system amplitude comparison function critically depends on input RF power, thus greatly limiting the dynamic range of the photonics-based receiver. Some approaches to solve these issues are also discussed.

Comments on X. Yin, A. Wen, Y. Chen, and T. Wang, `Studies in an optical millimeter-wave generation scheme via two parallel dual-parallel Mach-Zehnder modulators', Journal of Modern Optics, 58(8), 2011, pp. 665-673

Abstract: Yin et al. have described an innovative filter-less optical millimeter-wave generation scheme for octotupling of a 10 GHz RF oscillator, or sedecimtupling of a 5 GHz RF oscillator using two parallel dual-parallel Mach–Zehnder modulators (DP-MZMs). The great merit of their design is the suppression of all harmonics except those of order 4l (octotupling) or all harmonics except those of order 8l (sedecimtupling), where l is an integer. A demerit of their scheme is the requirement to set a precise RF signal modulation index in order to suppress the zeroth order optical carrier. The purpose of this comment is to show that, in the case of the octotupling function, all harmonics may be suppressed except those of order 4l, where l is an odd integer, by the simple addition of an optical π phase shift between the two DP-MZMs and an adjustment of the RF drive phases. Since the carrier is suppressed in the modified architecture, the octotupling circuit is thereby released of the strict requirement to set the drive l...

Data Erasing and Rewriting Capabilities of a Colorless FPLD Based Carrier-Reusing Transmitter

Abstract: The inherent data-erasing functionality of a 10-Gb/s colorless Fabry-Perot laser diode (FPLD) wavelength controlled by reusing a downstream optical carrier with encoded data is explored. By operating the injection-locked colorless FPLD at high dc bias, the unique in situ data-erasing mechanism is attributed to the almost identical power-to-current slope, regardless of optical injection-locking level. When reusing the downstream carrier, the injection-locked upstream colorless FPLD can significantly suppress the extinction ratio of the residual 10-Gb/s downstream data from 7.1 to <; 1 dB. This facilitates direct reuse of the downstream carrier without the need for an additional data eraser. With the data-erasing capability under 0-dBm injection, the carrier-reused upstream transmission successfully delivers on-off keying data up to 10 Gb/s with a signal-to-noise ratio of 6.2 dB and an extinction ratio of 5.4 dB. Even with a downstream injection power value of only -9 dBm, the upstream bit error rate (BER) of such a dual functional colorless FPLD biased at ≥2I th indicates a BER of <; 1 × 10 -10 . This releases the typical demand on high power budget requested for downstream data transmission and carrier reusing. The large parametric tolerances of such a data-erasable and carrier-reusable colorless FPLD transmitter also facilitate its practical application in dense-wavelength-division multiplexed passive optical networks.

Optical device frequency response measurement apparatus and method

Abstract: The invention discloses an optical device frequency response measurement method and a system. The method is characterized in that an optical carrier wave signal of a single wavelength is input into a frequency shift module with a carrier wave so that an optical detection signal with a carrier wave component and a frequency shift component is acquired; after the signal passes through a device to be detected, a radio frequency signal is acquired through a beat frequency of an optical detection module; a radio frequency amplitude phase extraction module whose working frequency is the same with a frequency shift amount is used to extract an amplitude and a phase information of the radio frequency signal so that combination amplitude frequency response and phase frequency response of an optical device to be detected at two frequency component positions of the optical detection signal are obtained; through calculation, the amplitude frequency response and the phase frequency response at the two frequency component positions are acquired respectively; a wavelength of the optical carrier wave signal is changed and the above processes are repeated so that frequency response of the optical device to be detected is acquired. The invention also discloses an optical device frequency response measurement system. Compared to the prior art, by using the method and the system, the amplitude phase extraction module is only requested to measure a fixed single frequency point so that cost is greatly reduced and simultaneously a bandpass device can be measured.

Microwave generation with photonic frequency octupling using a DPMZM in a Sagnac loop

Abstract: A photonic microwave signal generation scheme with frequency octupling is proposed and experimentally demonstrated. The scheme is based on bi-directional use of a dual-parallel Mach–Zehnder modulator (DPMZM) in a Sagnac loop. The two sub-modulators in the DPMZM are driven by two low-frequency signals with a π/2 phase difference, and the dc biases of the modulator are all set at the maximum transmission points. Due to the velocity mismatch of the modulator, only the light wave along the clockwise direction is effectively modulated by the drive signals to generate an optical signal with a carrier and ±4th order sidebands, while the modulation of the light wave along the counterclockwise direction is far less effective and can be ignored. By properly adjusting the polarization of the light wave output from the Sagnac loop, the optical carrier can be significantly suppressed at a polarizer, and then an optical signal with only ±4th order sidebands is generated. In the experiment, a pure 24-GHz microwave signa...

A Novel Optical Frequency-Hopping Scheme for Secure WDM Optical Communications

Abstract: A novel optical frequency-hopping scheme in wavelength-division multiplexing (WDM) systems is proposed to achieve secure communications with high capacity Frequency hopping is realized by the hopping of digital signals among different channels In the proposed system, the signal from any source is separated into small segments in the time domain, and the segments are carried by more than one different-wavelength optical carrier All the optical waves in the proposed WDM system are modulated by signals from two or more sources at different times The signal from a certain source is also interference to signals from other sources Hopping, synchronization, de-hopping, and routing are all digitally implemented in field-programmable gate array chips The system is reconfigurable by software to adapt to different rates Slow frequency hopping, fast frequency hopping, and intermediate frequency hopping are all available A demonstration system is designed to support transmission speed from 0 to 10 Gb/s, and a video communication based on it is built to demonstrate the 1-Gb/s optical frequency-hopping system

Multi-service RoF links with colorless upstream transmission based on orthogonal phase-correlated modulation.

Abstract: We propose and experimentally demonstrate a full-duplex radio-over-fiber (RoF) system with colorless upstream transmission based on orthogonal phase-correlated modulation (OPM). This new OPM scheme, which realized by a polarization rotator (PR) and a single-driver Mach-Zahnder modulator (MZM) at the central office (CO), achieves polarization-orthogonality between the optical carrier (OC) and subcarriers generated by radio frequency (RF) signals. By adjusting a polarization controller (PC) in the remote access units (RAU), different modulation schemes can be flexibly implemented, e.g. double-sideband (DSB) modulation for low RF service and optical carrier suppression (OCS) modulation for millimeter-wave (mm-wave) service. In the meantime, the OC can be reused for the upstream transmission without any filtering and additional PC. A proof-of-concept experiment is conducted to demonstrate the feasibility of proposed scheme, where downstream 800-Mb/s orthogonal frequency division multiplexing (OFDM) signal at 58 GHz as an mm-wave service and 800-Mb/s OFDM signal at 0.3 GHz as a low frequency wireless service, as well as an upstream 1-Gb/s on-off keying (OOK) are simultaneously delivered in a shared architecture. By providing heterogeneous services and colorless upstream transmission, the proposed architecture can be seamlessly integrated in wavelength division multiplexing passive optical network (WDM-PON).

Multibeam radio frequency photonic beamformer using a multi-signal slow light time delay unit

Abstract: A photonic beamformer is disclosed and is configured to transmit or receive a plurality of RF input signals from a plurality of antennas. The beamformer receiver includes a plurality of optical modulators, each optical modulator being configured to modulate each of the RF input signals onto an optical carrier, each carrier having a different wavelength. The beamformer receiver also includes a plurality of optical amplifiers, each optical amplifier being configured to vary the optical power of one optical carrier based on a weighting input and generate a weighted optical carrier. The beamformer receiver also includes a plurality of multi-beam optical true-time delays (TTD), each TTD being configured to receive all of the weighted optical carriers and generate a plurality time delayed optical carriers. The beamformer receiver also includes a plurality of detectors configured to detect each of the plurality time delayed optical carriers and generate an electrical signal that represents each of the plurality of received RF input signals.

Calibration-free and bias-drift-free microwave characterization of dual-drive Mach–Zehnder modulators using heterodyne mixing

Abstract: An electrical method is proposed for the microwave characterization of dual-drive Mach–Zehnder modulators based on heterodyne mixing. The proposed method utilizes the heterodyne products between the two-tone modulated optical sidebands and frequency-shifted optical carrier, and achieves calibration-free and bias-drift-free microwave measurement of dual-drive Mach–Zehnder modulators with high resolution electrical-domain techniques. Our method avoids the extra calibration for the photodetector and reduces half the bandwidth requirement for the photodetector and the electrical spectrum analyzer through carefully choosing a half frequency relationship of the two-tone modulation. Moreover, our measurement avoids the bias drifting problem due to the insensitivity to the bias phase of the modulator under test. The frequency-dependent modulation depths and half-wave voltages are measured for a commercial dual-drive Mach–Zehnder modulator with our method, which agree well with the results obtained by the conventional optical spectrum analysis method.

Tunable single passband microwave photonic filter based on DFB-SOA-assisted optical carrier recovery

Abstract: A tunable single passband microwave photonic filter (MPF) based on a distributed-feedback semiconductor optical amplifier (DFB-SOA) is proposed and experimentally demonstrated in this paper The fundamental principle is to recover the suppressed optical carrier from a passband optical filter by the wavelength-selective amplification of the DFB-SOA A microwave signal is then generated by beating the recovered optical carrier with the phase modulated lower sideband and thus a MPF is achieved with the shape of the passband optical filter which is mapped from optical domain to electrical domain By tuning the central wavelength of the passband optical filter, a single passband MPF with frequency tuning range from 5 to 35 GHz is obtained The 3-dB bandwidth and the out-of-band suppression ratio are measured to be 4 GHz and 20 dB, respectively

Analog photonic link based on the Aulter–Townes splitting induced dual-band filter for OCS and the SOI signal processor

Abstract: Analog photonic link (APL) is attractive for its potential high performance of larger dynamic range, tunability, and immunity to electromagnetic interference (EMI). An APL based on the Aulter-Townes splitting (ATS)-effect-induced dual-band filter for optical carrier suppression (OCS) and the SOI signal processor has been proposed and experimentally demonstrated. The bandwidths of the two passbands are approximately 780 MHz, and the interval could be tuned from 8 GHz to more than 80 GHz in simulation. The extinction ratio is larger than 20 dB, which can provide a 20-dB suppression of the optical carrier and higher order sidebands to obtain clean optical carrier and local oscillator (LO) for modulation and down-conversion. The down-conversion APL based on the proposed dual-band OCS filter at X-band has been presented, and the spurious free dynamic range (SFDR) of the link is measured to be as high as 102.2 dB-Hz(2/3).

Bidirectional multiband radio-over-fiber system based on polarization multiplexing and wavelength reuse.

Abstract: A polarization multiplexing technique based on phase-shift-induced polarization modulation-to-intensity modulation (PloM-to-IM) convertor and a Mach-Zehnder modulator (MZM) is proposed to generate multi-band signals. Successful transmission of the traditional radio frequency, microwave (MW) and millimeter wave (MMW) signals is simultaneously achieved. Meanwhile, the intensity-constant optical carrier (OC) is reused for upstream 25-km transmission.

Full-duplex fiber-wireless link for alternative wired and 40-GHz band wireless access based on differential quaternary phase-shift optical single sideband millimeter-wave signal

Abstract: A full-duplex fiber-wireless link with a uniform single sideband differential quaternary phase-shift keying optical millimeter-wave signal is proposed to provide wired or 40-GHz band wireless access alternatively. The uniform optical millimeter-wave signal that supports services for wired or wireless users is produced via an LiNbO3 Mach-Zehnder modulator. After being transmitted to the hybrid optical network unit (HONU), it can be demodulated in different patterns on the demand of the user terminals for wired or wireless access. Simultaneously, part of the blank optical carrier abstracted from it is reused as the uplink optical carrier, so the HONU is free from the laser source, and thus, the complexity and cost of the system are reduced. Moreover, since the two tones of the dual-tone optical millimeter wave come from the same source, they maintain high coherency even after being transmitted over fiber. Additionally, the downlink data are carried by one tone of the dual-tone optical millimeter wave, so the downlink optical millimeter-wave signal suffers little from the fiber chromatic dispersion and laser phase noise. The theoretical analysis and simulation results show that our proposed full-duplex link for alternative wired and wireless access maintains good performance even when the transmission link with standard single mode fiber is extended to 30 km.

All Colorless FPLD-Based Bidirectional Full-Duplex DWDM-PON

Abstract: All colorless Fabry–Perot laser diodes (FPLDs) with master-to-slave injection-locking and carrier-reusing are employed as down- and up-stream transmitters to demonstrate the bidirectionally 10-Gbit/s full-duplex on–off-keying transmission in a dense wavelength-division-multiplexed passive optical network system without using any high-coherent transmitter. By simply injecting the down-stream optical carrier into the up-stream slave colorless FPLD, the residual down-stream data can be greatly suppressed with a penalty on the relative intensity noise by only 2–4 dB. This facilitates a compact carrier-reusing without the need of additional data-eraser or injection master. Such a broadband colorless FPLD master can essentially make the down-stream slave approaching an error-free transmission after transmitting over 25-km MetroCor fiber at a receiving power of <−13.5 dBm. By reusing the down-stream carrier with its data in-situ erased by the up-stream colorless FPLD itself, the single-mode injection-locked up-stream slave can also implement an error-free transmission after propagating over 25 km, providing a receiving power sensitivity of <−9 dBm with a power penalty of 2 dB as compared to the back-to-back case.