Passive Optical Networks(PONs)are considered as the preferred solution for broadband fibre-based access networks.This is because PONs present low cost deployment,low energy consumption and also meet high bandwidth dem...Passive Optical Networks(PONs)are considered as the preferred solution for broadband fibre-based access networks.This is because PONs present low cost deployment,low energy consumption and also meet high bandwidth demands from end users.In addition,end users expect a high availability for access networks,while operators are more concerned about reducing the failure impact(number of clients affected by failures).Moreover,operators are also interested in reducing the cost of the access network.This paper provides a deep insight into the consequences that the physical topology and design decisions cause on the availability,the failure impact and the cost of a PON.In order to do that,the physical layout of the PON deployment area is approximated by a network geometric model.A PON deployed according to the geometric model is then assessed in terms of failure impact,availability and cost.This way,the effects of different design decisions and the physical layout on these three parameters are evaluated.In addition,the tradeoffs between availability,failure impact and cost caused by planning decisions and the physical topology are identified and pinpointed.展开更多
We propose a scheme for mitigating Rayleigh backscattering noise and demodulating differential phase- shift keying （DPSK） signals in wavelength-division-multiplexed passive optical networks （WDM-PONs） with injecti...We propose a scheme for mitigating Rayleigh backscattering noise and demodulating differential phase- shift keying （DPSK） signals in wavelength-division-multiplexed passive optical networks （WDM-PONs） with injection-locked Fabry-Perot laser diodes （FP-LDs）. Signal demodulation and wavelength conversion are simultaneously realized on the basis of the frequency deviation and red shift of longitude modes in the FP-LDs. Experimental results demonstrate that the demodulation and wavelength conversion of 2.5-Gb/s DPSK signals are achieved. A power penalty of about 1.6 dB at a bit error rate of 10.9 is measured after transmission over 25-km single mode fiber.展开更多
Pulse position modulation （PPM） is introduced downstream of the reflective semiconductor optical am- plifier （RSOA）-based single-fiber full-duplex bidirectional wavelength division multiplex passive optical netwo...Pulse position modulation （PPM） is introduced downstream of the reflective semiconductor optical am- plifier （RSOA）-based single-fiber full-duplex bidirectional wavelength division multiplex passive optical network （WDM PON） to suppress the interference brought by the remodulation effect in the RSOA, Rayleigh backscattering, and reflection of the connection devices. In addition, because of the power- efficient characteristic of the PPM-encoded signals, the power budget shows clear improvement. As the experimental tests indicate, with -6 dB extinction ratio （ER） in the downstream signal, the receiving sensitivity of the PPM-encoded channel is -2.6 and -3 dB higher than that of the NRZ （Non-return to zero）-encoded channel in the downlink and uplink, respectively.展开更多
We report the fabrication of widely tunable ridge waveguide distributed Bragg reflector （DBR） lasers with InGaAsP butt-joint as grating material. The shape of the butt-joint interface is found to have significant ef...We report the fabrication of widely tunable ridge waveguide distributed Bragg reflector （DBR） lasers with InGaAsP butt-joint as grating material. The shape of the butt-joint interface is found to have significant effect on the properties of the lasers. It is shown that irregular mode jumps during wavelength tuning can be avoided by a V-shaped butt-joint interface. From the fabricated device, 23 channels with 0.8 nm spacing and greater than 35 dB side mode suppression ratios are obtained. The different tuning characteristics of the ridge waveguide and the previously reported buried ridge stripe DBR lasers are discussed. Combined with the wide tuning range and the simple structure, the ridge waveguide DBR lasers are promising for use in wavelength division multiplexing passive optical networks （WDM-PONs）.展开更多
Orthogonal frequency division multiplexing-passive optical network （OFDM-PON） and single-carrier fre- quency division multiplexing （SCFDM）-PON are promising solutions for future high-speed PON-based access. A pola...Orthogonal frequency division multiplexing-passive optical network （OFDM-PON） and single-carrier fre- quency division multiplexing （SCFDM）-PON are promising solutions for future high-speed PON-based access. A polarization division multiplexing scheme with direct detection is proposed for OFDM-PON to effectively reduce bandwidth requirements for components. However, the scheme strictly requires spec- trum overlapping of two orthogonal sidebands and the 4 × 4 multi-input-multi-output （MIMO） algorithm to eliminate complex cross-polarization interference. In this letter, we propose a polarization interleaving （PI） approach that significantly reduces bandwidth requirements for optical and electrical components while achieving a high-flexibility and low-complexity MIMO algorithm. Downstream single sideband PI-SCFDM transmission is experimentally demonstrated.展开更多
This letter presents a low cost solution for wavelength division multiplexed orthogonal frequency division multiplexed passive optical network （WDM-OFDM-PON） with widely tunable optical filter and linear small form-...This letter presents a low cost solution for wavelength division multiplexed orthogonal frequency division multiplexed passive optical network （WDM-OFDM-PON） with widely tunable optical filter and linear small form-factor pluggable （SFP） module. With 9-nm tunable range from 1551 to 1560 nm, the tunable filter can support up to 10-channel 100-GHz spacing WDM PON system. A linear avalanche photodiode （APD） based SFP＋ module is designed for optical OFDM signal demodulation, which can provide better receiver performance compared with limiting APD module. Experimental results show that -34 dB power budget can be achieved in 4x5-Gbps WDM-OFDM-PON system, which can satisfy the transmission requirements of next generation PON system.展开更多
基金Norwegian University of Science and Technology(Project 43255)
文摘Passive Optical Networks(PONs)are considered as the preferred solution for broadband fibre-based access networks.This is because PONs present low cost deployment,low energy consumption and also meet high bandwidth demands from end users.In addition,end users expect a high availability for access networks,while operators are more concerned about reducing the failure impact(number of clients affected by failures).Moreover,operators are also interested in reducing the cost of the access network.This paper provides a deep insight into the consequences that the physical topology and design decisions cause on the availability,the failure impact and the cost of a PON.In order to do that,the physical layout of the PON deployment area is approximated by a network geometric model.A PON deployed according to the geometric model is then assessed in terms of failure impact,availability and cost.This way,the effects of different design decisions and the physical layout on these three parameters are evaluated.In addition,the tradeoffs between availability,failure impact and cost caused by planning decisions and the physical topology are identified and pinpointed.
基金supported by the National "973" Project of China(Nos.2010CB328205,2010CB328204,and 2012CB315602)the National Natural Science Foundation of China(Nos.60972032,61090393,61132004,and 60825103)the National "863" Project of China
文摘We propose a scheme for mitigating Rayleigh backscattering noise and demodulating differential phase- shift keying （DPSK） signals in wavelength-division-multiplexed passive optical networks （WDM-PONs） with injection-locked Fabry-Perot laser diodes （FP-LDs）. Signal demodulation and wavelength conversion are simultaneously realized on the basis of the frequency deviation and red shift of longitude modes in the FP-LDs. Experimental results demonstrate that the demodulation and wavelength conversion of 2.5-Gb/s DPSK signals are achieved. A power penalty of about 1.6 dB at a bit error rate of 10.9 is measured after transmission over 25-km single mode fiber.
基金supported by the National Natural Science Foundation of China(No.61072008)the National "863" Project of China(No.2009AA01z255)+3 种基金the National "111" Project of China(No.B07005)the Beijing New Star Programme of Science and Technologies(No. 2007A048)the Fundamental Research Funds for Central Universities(Nos.2009GYBZ and 2009RC0401)the Program for Excellent Talents in BUPT
文摘Pulse position modulation （PPM） is introduced downstream of the reflective semiconductor optical am- plifier （RSOA）-based single-fiber full-duplex bidirectional wavelength division multiplex passive optical network （WDM PON） to suppress the interference brought by the remodulation effect in the RSOA, Rayleigh backscattering, and reflection of the connection devices. In addition, because of the power- efficient characteristic of the PPM-encoded signals, the power budget shows clear improvement. As the experimental tests indicate, with -6 dB extinction ratio （ER） in the downstream signal, the receiving sensitivity of the PPM-encoded channel is -2.6 and -3 dB higher than that of the NRZ （Non-return to zero）-encoded channel in the downlink and uplink, respectively.
基金supported by the National Natural Science Foundation of China(Nos.61274071,61006044,and 61090392)the National"863"Project of China(Nos.2013AA014502 and 2011AA010303)the National"973"Program of China(No.2012CB934202)
文摘We report the fabrication of widely tunable ridge waveguide distributed Bragg reflector （DBR） lasers with InGaAsP butt-joint as grating material. The shape of the butt-joint interface is found to have significant effect on the properties of the lasers. It is shown that irregular mode jumps during wavelength tuning can be avoided by a V-shaped butt-joint interface. From the fabricated device, 23 channels with 0.8 nm spacing and greater than 35 dB side mode suppression ratios are obtained. The different tuning characteristics of the ridge waveguide and the previously reported buried ridge stripe DBR lasers are discussed. Combined with the wide tuning range and the simple structure, the ridge waveguide DBR lasers are promising for use in wavelength division multiplexing passive optical networks （WDM-PONs）.
基金supported by the National "973" Program of China (Nos. 2010CB328201 and 2010CB328202)the National Natural Science Foundation of China (Nos.60907030, 60736003, and 60931160439)the National"863" Program of China (No. 2011AA01A106)
文摘Orthogonal frequency division multiplexing-passive optical network （OFDM-PON） and single-carrier fre- quency division multiplexing （SCFDM）-PON are promising solutions for future high-speed PON-based access. A polarization division multiplexing scheme with direct detection is proposed for OFDM-PON to effectively reduce bandwidth requirements for components. However, the scheme strictly requires spec- trum overlapping of two orthogonal sidebands and the 4 × 4 multi-input-multi-output （MIMO） algorithm to eliminate complex cross-polarization interference. In this letter, we propose a polarization interleaving （PI） approach that significantly reduces bandwidth requirements for optical and electrical components while achieving a high-flexibility and low-complexity MIMO algorithm. Downstream single sideband PI-SCFDM transmission is experimentally demonstrated.
基金supported by the National Natural Science Foundation of China(Nos.61271216,61221001,61132004,and 61090393)the National "973" Program of China(Nos.2010CB328205,2010CB328204,and2012CB315602)the National "863" Program of China(No.2011AA01A100)
文摘This letter presents a low cost solution for wavelength division multiplexed orthogonal frequency division multiplexed passive optical network （WDM-OFDM-PON） with widely tunable optical filter and linear small form-factor pluggable （SFP） module. With 9-nm tunable range from 1551 to 1560 nm, the tunable filter can support up to 10-channel 100-GHz spacing WDM PON system. A linear avalanche photodiode （APD） based SFP＋ module is designed for optical OFDM signal demodulation, which can provide better receiver performance compared with limiting APD module. Experimental results show that -34 dB power budget can be achieved in 4x5-Gbps WDM-OFDM-PON system, which can satisfy the transmission requirements of next generation PON system.
