Temperature and metal composition dependence of lateral photovoltaic effect in Al-Alq3/SiO2/Si structures

By using PDM-OFDM-16QAM modulation, all-Raman amplification, coherent detection, and 7% forward error correction （FEC） threshold, we successfully demonstrate 63-Tb/s （368× 183.3-Gb/s） signal over 160- km standard single mode fiber （SSMF） transmission in the C- and L-bands with 25-GHz channel spacing. 368 optical channels with bandwidth spacing of 25 GHz are generated from 16 external cavity laser sources. After 160-km SSMF transmission, all tested bit error rate （BER） are under 3.8×10^-3, which can be recovered by 7% FEC threshold. Within each channel, we achieve the spectral efficiency of 6.85 bit/s/Hz in C/L band.     

Experiment on 60-GHz MMW transmission performance in an optical fiber and wireless system

We experimentally investigate the transmission performance of 60-GHz signals over standard single-mode fiber (SSMF) and wireless links at different bit rates. Experimental results show that in a transmission of over 10-km SSMF and 1.3-m wireless link, bit rate reaches up to 5 Gb/s and bit error rate (BER) is less than 10 4 . The main limiting factor in such radio-over-fiber (ROF) systems is intersymbol interferences caused by the so-called walk-off effect when BER is below 10 8 . In addition, a transmission of over 20-km SSMF without chromatic dispersion compensation is briefly investigated. For a BER of 10 8 , the optical penalty is 2 dB.     

8 × 10-Gb/s transmission system over 1500 km on G.652 fiber dispersion compensated by chirped fiber gratings

A low cost 8 × 10-Gb/s transmission system over 1500 km on conventional fiber using chirped fiber Bragg grating (CFBG) as dispersion compensator is demonstrated. The bit error rate (BER) below 10-10 at 1500 km is obtained. The channel spacing is 0.8 nm and the optical amplifier spacing is 100 km. Only 16 erbium-doped fiber amplifiers (EDFAs) are used.     

Study on the 4×10 Gb/s,400 km dispersion compensation by chirped optical fiber grating

In this paper, the dispersion compensation for 4×10 Gb/s, 400 km G.652 fiber by chirped optical fiberBragg grating (FBG)is introduced.For the first time,we have measured and compensated the polarizationmode dispersion(PMD)of FBG, which in each channel is less than 1.1 ps.When the bit crror rate(BER)is 10~(-10)and the bit error is zero, the transmission power penalty of each channel is less than 2 dB, andthe best, result is negative which means that the receiver sensitivity is increased after transmission.     

Adaptive multiple-input multiple-output mode switching for indoor visible light communication system with orthogonal frequency division multiplexing modulation

We propose and experimentally demonstrate an adaptive multiple-input multiple-output(MIMO) mode switching scheme for an indoor visible light communication system combined with orthogonal frequency division multiplexing modulation.Only requiring 1 bit feedback from the receiver,the MIMO mode at the transmitter switches between spatial multiplexing and transmit diversity adapting to the channel correlation.In such a way,we can take advantage of both spatial multiplexing and transmit diversity,where the spatial multiplexing benefits for its multiplexing gain in the low channel correlation environment,and the transmit diversity is robust to high channel correlation.Experimental results validate the performance improvement over the pure spatial multiplexing or transmit diversity system.With the increasing of the channel correlation,the measured bit error rates of the proposed system are below the 7% pre-forward error correction(pre-FEC) limit of 3.8 × 10~(-3)when the transmitted data rate is 50 Mb/s,and below the 20% pre-FEC threshold of 5.0 × 10~(-2) when the transmitted data rate is raised up to 100 Mb/s.     

Stable error-free single channel 160-Gb/s OTDM 100-km transmission via high-precision dispersion management

<正>A single channel with a 160-Gb/s optical time-division-multiplexing(OTDM) transmission over 100 km is fabricated.With the help of 500-GHz optical sampling oscilloscopes,the fiber length is adjusted to the order of 10 m,which corresponds to the accuracy of 0.4 ps for the dispersion compensation.The dispersion map is optimized for the 100-km transmission link.A completely error-free transmission with the power penalty of 3.6 dB is achieved for 2 h without using forward error correction.     

MISO visible light communication system utilizing hybrid post-equalizer aided pre-convergence of STBC decoding

In this Letter, we propose a modified hybrid linear and nonlinear post-equalizer to aid pre-convergence of space–time block coding(STBC) decoding in the formulated multiple-input-single-output(MISO) visible light communication(VLC) model. Meanwhile, we present a channel estimation algorithm, as the existing method is suboptimal. Experiments demonstrate that a data rate of 1 Gbit/s is easily achieved in 1.3 m indoor free space transmission with the bit error rate(BER) limited to 3.8 × 10~(-3). Correspondingly, the Q factor can be improved to 3.13 d B compared to the pure linear equalizer case.     

The system of L-band 2×10 Gb/s WDM transmission over conventional single mode fibre with 600 km by chirped fibre Bragg gratings dispersion compensation

A chirped fibre Bragg grating according to ITU-T suggested L-band (2nd channel $\lambda _{1}=1570.83$~nm; 80th channel $\lambda _{2}=1603.57$ nm) with more than 1800 ps/nm single channel dispersion compensation is presented in this paper, of which the cladding mode loss, the delay curve ripple and the power fluctuation of the reflected spectrum are less than 0.5 dB, 50 ps and 0.25 dB, respectively. With this new FBG as dispersion compensation device, a $2\times 10$ Gb/s wavelength division multiplexing (WDM) L-band transmission of 600 km based on conventional single mode fibre (G.652 fibre) is performed without forward error correction. The bit error rate (BER) is less than 10$^{ - 12}$ and the power penalties of the 2{nd} and 80{th} channel of L-band are 1.8~dB and 2.0~dB, respectively.     

Cascaded optical frequency transfer over 500-km fiber link using regenerative amplifier

We demonstrate a 300-km +200-km cascaded coherent phase transfer via fiber link. The transfer is divided into a 300-km span and a 200-km span with independent phase locking loops, aiming to extend the phase control bandwidth of the whole link. The phase noise and transfer instability of the cascaded transmission are investigated and compared with those in the case of a single-span 500-km transfer. We achieve the transfer instabilities of 1.8 × 10~(-14) at 1 s, 8.9× 10~(-20) at 10~4 s for the 300-km +200-km cascaded transmission, and 2.7×10~(-14) at 1 s for the 500-km single-span transfer.     

Data-aided channel estimation and frequency domain equalization of minimum-shift keying in optical transmission systems

We demonstrate a digital optical communication system based on minimum shift keying （MSK） signal transmission with coherent detection. 5-Gb/s MSK signal can transmit over a 160-km standard single mode fiber （SSMF） without phase compensation. At the receiver, we use data-aided channel estimation and frequency domain equalization （FDE） techniques in the digital signal processing （DSP） algorithm, then analyze its performance characteristics compared with quadrature phase shift keying （QPSK） format. The simulation results show that the MSK format will be a potential candidate for next-generation access network.     

The system of L-band 2 × 10 Gb/s WDM transmission over conventional single mode fibre with 600 km by chirped fibre Bragg gratings dispersion compensation

A chirped fibre Bragg grating according to ITU-T suggested L-band （2nd channel λ1 = 1570.83 nm; 80th channel λ2 = 1603.57 nm） with more than 1800 ps/nm single channel dispersion compensation is presented in this paper, of which the cladding mode loss, the delay curve ripple and the power fluctuation of the reflected spectrum are less than 0.5 dB, 50 ps and 0.25 dB, respectively. With this new FBG as dispersion compensation device, a 2 × 10 Gb/s wavelength division multiplexing （WDM） L-band transmission of 600 km based on conventional single mode fibre （G.652 fibre） is performed without forward error correction. The bit error rate （BER） is less than 10-12 and the power penalties of the 2nd and 80th channel of L-band are 1.8 dB and 2.0 dB, respectively.     

High-speed polarization mode dispersion compensation in a 43-Gb/s RZ-DQPSK transmission system over 1200 km of standard single-mode fibre

This paper reports that the designed optical polarization mode dispersion compensator shows a good performance under the real-time variation of differential group delay, state of polarization and principal state of polarization in a (40 × 43)-Gb/s dense-wavelength-multiplexing, 1200-km enhanced return-to-zero differential-quadrature-phase-shift-keying (RZ-DQPSK) system. The polarization mode dispersion tolerance of the system is improved by 26 ps using the optical polarization mode dispersion compensator. The short and long time stabilities are tested with the bit error ratio recorded.vspace1mm     

A cost-effective 100-Gb/s transmitter with low-speed optoelectronic devices and high spectral efficiency

A 100-Gb/s high-speed optical transmitter is proposed and experimentally demonstrated.Based on frequency-quadrupling technique,two sub-channels with a fixed 50-GHz spacing are obtained from one laser source.Using return-to-zero differential quadrature phase-shift keying (RZ-DQPSK) modulation format and polarization multiplexing (PolMux),only low-speed electronic devices of 12.5 GHz are needed for the 100-Gb/s transmitter.This eliminates the need of ultrahigh-speed optoelectronic devices and thus greatly reduces the cost.The experimental results show that this transmitter can achieve good perfor- mance in dispersion tolerance of a 25-km single mode fiber (SMF).     

40-Gb/s star 16-QAM transmitter based on single dual-drive Mach-Zehnder modulator

We propose a 40-Gb/s star 16-ary quadrature amplitude modulation （16-QAM） transmitter using a single dual-drive Mach-Zehnder modulator （DDMZM）. This transmitter is demonstrated through experiment and simulation and shows the advantage of simplicity for implementation. Simulation results indicate that error free performance could be achieved for the generated signal after 80-km standard single-mode fiber （SSMF） transmission with coherent detection scheme.     

1.5μm, 8×12.5Gb/s of hybrid-integrated TOSA with isolators and ROSA for 100GbE application

Compact transmitter and receiver optical sub-assemblies(TOSA and ROSA) are fabricated in our laboratory and have an aggregated capacity of 100 Gb/s. Specially, directly modulated laser(DML) drivers with two layers of electrical circuit boards are designed to inject RF signals and bias currents separately. For all the lanes, the3 dB bandwidth of the cascade of the TOSA and ROSA exceeds 9 GHz, which allows the 12.5 Gb/s operation.With the 12.5 Gb/s × 8-lane operation, clear eye diagrams for back-to-back and 30-km amplified transmission with a dispersion compensation fiber are achieved. Low cost and simple processing technology make it possible to realize commercial production.     

40-Gb/s PolMux-QPSK transmission using low-voltage modulation and single-ended digital coherent detection

We demonstrate a novel 40-Gb/s transmission system over a 10×101-km standard single mode fiber (SSMF) loop. This system features polarization multiplexed quadrature phase shift keying (PolMux-QPSK), lowvoltage modulation of 2-V peak-to-peak signal amplitude, and home-made 90° optical hybrid with singleended digital coherent detection. Any power amplifers before the modulator and balanced detectors are not used. In the case of low-voltage modulation, coherent detection is much less sensitive to modulator bias offset than delay interferometer-based demodulation.     

Investigation on the pre-compensation and post-compensation cascaded multi-channel-chirped fiber Bragg gratings for a repeaterless transmission system

We experimentally designed dispersion-managed repeaterless transmission systems with a pre-compensation and post-compensation technique using multi-channel-chirped fiber Bragg gratings. The repeaterless transmission link supports a single channel(1548.51 nm) with a 10 Gbps repeaterless transmission system over 300 km standard single-mode fiber(SSMF). In the system design, two distributed Raman amplifiers(DRAs) were used to improve the signal level propagated along the 300 km SSMF. The co-propagating DRA provided 15 dB on–off gain and the counter-propagating produced 32 dB on–off gain at the signal wavelength. The experiment results show that the post-compensation configuration achieves an optimal performance with a bit error rate at 1 × 10~(-9).     

160 km all-optical OFDM transmission system with inline chromatic dispersion compensation

An experimental demonstration of an all-optical sampling orthogonal frequency division multiplexing (AOS-OFDM) transmission system with inline chromatic dispersion (CD) compensation is carried out to test the nonlinear influence. With five subcarriers non-return-to-zero (NRZ) modulated, the total bit rate is 50 Gb/s without polarization multiplexing. The receiver end is highly simplified with direct detection using optical Fourier transform filter. After transmission in 160-km standard single-mode fiber (SSMF) link with 130-ps/nm residual CD, an optimum input optical power for the system performance is achieved.     

Ultra-Long Haul L-Band WDM Transmission over a Standard Single-Mode Fibre Loop Using DCF＋CFBG Hybrid Dispersion Compensation

We demonstrate a 10. 7Gb/s-line-rate L-band wavelength-division-multiplexer （WDM） loop transmission over a 1890-kin standard single-mode fibre （SSMF） with a 100-km amplifier spacing as well as non-return-to-zero （NRZ） format. The dispersion compensating fibre （DCF） plus chirped tibre Bragg grating （CFBG） is employed for hybrid inline dispersion compensation. The power penalty of each channel is less than 3 dB after three-loop transmission. The experimental results show that high-performance CFBGs can be successfully used in ultra-long haul （〉 1000km） WDM systems. We also point out that the all-CFBG compensation scheme is not suitable for re-circulating loop transmissions.     

Improving performance of 750-Mb//s visible light commun- ication system using adaptive Nyquist windowing

We propose a configuration of a wavelength division multiplexing （WDM）-visible light communication （VLC） system using orthogonal frequency division multiplexing （OFDM） modulation and an adaptive Nyquist windowing of the OFDM signal in the receiver. Based on this configuration, we demonstrate a 750-Mb/s WDM-VLC transmission based on RGB light-emitting diode （LED） with a distance of 70 cm. The measured bit error rate （BER） for all channels are under the pre-forwaxd error correction limit of 3,8 × 10-3. The BER performances of all the channels of the proposed WDM-VLC system show considerable improvement compared with those of the system without Nvauist windowing.