Rayleigh Scattering Robust Access Network by λ-Shifting through Extraction of Suppressed RZ Clock Harmonic (original) (raw)
Self optical pulsation based RZ-BPSK and reused RZ-OOK bi-directional OC-768 transmission
Journal of Lightwave Technology, 2014
The generation and reusing of a self-pulsated optical RZ carrier is demonstrated to achieve bi-directional OC-768 transmission with downstream return-to-zero binary phase-shift keying (RZ-BPSK) and reused upstream return-to-zero ON-OFF keying (RZ-OOK) data formats at 40-Gbit/s. The self-started optical RZ carrier is generated by linking a single-mode laser with a nonlinearly biased Mach-Zehnder modulator based self-feedback loop, which is externally modulated to transmit the downstream RZ-BPSK and reused to transmit the upstream RZ-OOK. By lengthening the true-time delay in the self-feedback loop with a 900-m long SMF, the self-started 40-GHz photonic-microwave clock with an ultralow SSB phase noise of-160 dBc/Hz at an offset frequency of 100 kHz could suppress its relative timing jitter to 2 fs for obtaining a Q-factor as high as 5 × 10 16. Both the photon-microwave clock and optical RZ carrier can be triggered to achieve bi-directional downstream RZ-BPSK and upstream reused RZ-OOK transmissions with receiving power sensitivities of-15.7 and-12.3 dBm, respectively, at a requested BER of 10 −9. The bi-directional downstream RZ-BPSK data reveals a comparable BER performance with the uni-directional case by a power penalty of only 0.5 dB, whereas the power penalty between uni-and bidirectional upstream RZ-OOK data is up to 3 dB.
Performance improvement of optical RZ-receiver by utilizing an all-optical waveform converter
Optics Express, 2005
A practical receiver scheme with all-optical waveform conversion is proposed and demonstrated. To mitigate influence of the timing jitter of the received signal, the proposed receiver employs a semiconductor optical amplifier (SOA)-based waveform converter, which can generate signal pulses with a rectangular-like profile. We have evaluated the receiver performances of the conventional and proposed schemes. The receiver sensitivity improvement of 0.7 dB and the phase-margin enlargement of 60 % were simultaneously achieved in comparison with the conventional receiver scheme.
All-Optical RZ-to-NRZ Conversion of Advanced Modulated Signals
IEEE Photonics Technology Letters, 2000
A generic scheme for return-to-zero (RZ) to nonreturn-to-zero (NRZ) format conversion of optical signals is analyzed. It relies on a simple delay interferometer with frequency periodicity twice as high as the input symbol rate and a subsequent optical band-pass filter. Simulation results at 40 Gbaud indicate the compatibility of the technique with a variety of advanced modulation formats. RZ-to-NRZ conversion of 40 Gb/s differential phase shift keying signals is experimentally demonstrated with 1.5 dB power penalty compared to the backto-back measurement.
IEEE Journal of Selected Topics in Quantum Electronics, 2000
We investigate the effect of the backward injecting linewidth on the rise/fall time, duty cycle, and frequency chirp of the 10 Gb/s format-converted pulsed return-to-zero (RZ) data stream from the traveling-wave semiconductor optical amplifier (TWSOA) with its gain profile temporally and spectrally reshaping by a backward injected single-or multimode inverse-opticalcomb. The rising time remains almost unchanged; however, the falling time was monotonically reduced by increasing injection power. The evolution of full-width at half-maximum with injection power exhibits similar trend with falling time. In comparison with single-mode inverse-optical-comb injection, the multimode injection exhibits frequency-chirp reduction and better ON/OFF extinction performances. Under the injection of multi-and single-mode inverse-optical-combs into the TWSOA at extremely high gain condition, the multi-and single-mode injection converted pulsed RZ data pulsewidths are 32 and 31 ps with corresponding peak-topeak chirps of 10 and 12 GHz, respectively. The chirp can abruptly be reduced to 1.2 GHz by reducing the TWSOA biased current to 100 mA.
Optical clock recovery from 10-Gb/s NRZ signal
Microwave and Optical Technology Letters, 2004
ABSTRACT All optical clock recovery has been experimentally demonstrated by an actively mode-locked fiber ring based on the semiconductor optical amplifier (SOA) from a 10-Gb/s NRZ data stream. The system exploits the cross-gain modulation (XGM) nonlinear effect in SOA, and a Fabry–Perot etalon suitably inserted in the loop improves the mode-locking stabilization and efficiency. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 435–437, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20328
IEEE Photonics Technology Letters, 2007
We demonstrate a simple configuration for clock recovery from a nonreturn-to-zero signal, which is preprocessed by a narrowband filter. Evidently, the clock component is enhanced after the filter. Compared with previous preprocessing schemes, the single filter is simple and suitable for different bit rates. The output performances related to the bandwidth and the detuning of the filter are analyzed. By cascading a clock recovery unit with semiconductor optical amplifier based fiber ring laser, the clock signal can be extracted from the preprocessed signal, at 10 to 40 Gb/s. By simply using a filter with larger bandwidth, much higher operation can be achieved easily. Index Terms-Clock component enhancement, clock recovery, different bit rates, nonreturn-to-zero (NRZ).
RZ to CSRZ format and wavelength conversion with regenerative properties
2009 Conference on Optical Fiber Communication - OFC 2009, 2009
A 40 Gb/s all-optical modulation format conversion from return-to-zero (RZ) to carrier suppressed return-to-zero (CSRZ) with simultaneous regenerative wavelength conversion is introduced relaying on a versatile scheme of a single SOA followed by a filter.