Tunable coherent emission is generated in a single-pass, cascaded wavelength conversion process from mode-locked laser-pumped monolithic periodically poled lithium niobate(PPLN). Three ranges of wavelength, includin...Tunable coherent emission is generated in a single-pass, cascaded wavelength conversion process from mode-locked laser-pumped monolithic periodically poled lithium niobate(PPLN). Three ranges of wavelength, including visible output from 628 nm to 639 nm, near-infrared output from 797 nm to 816 nm, and mid-infrared output from 3167 nm to 3459 nm,were obtained from the monolithic PPLN, which consists of a 10-mm section for 532-nm-pumped optical parametric generation(OPG) and a 7-mm section for 1064-nm-pumped sum frequency generation(SFG). A pump-to-signal conversion efficiency of 23.4% for OPG at 50°C and a quantum efficiency of 26.2% for SFG at 200°C were obtained.展开更多
Taking into account ultra-fast carrier dynamics, this paper models 640 Gbit/s wavelength conversion scheme based on nonlinear polarization rotation (NPR) in a single semiconductor optical amplifier (SOA) and inves...Taking into account ultra-fast carrier dynamics, this paper models 640 Gbit/s wavelength conversion scheme based on nonlinear polarization rotation (NPR) in a single semiconductor optical amplifier (SOA) and investigates the performance of this kind of wavelength conversion scheme in detail. In this model, two carrier temperature equations are introduced to substitute two energy density equations, which reduce the complexity of calculation in comparison with the previous model. The temporary gain and phase shift dynamics induced by ultra-short optical pulses are numerically simulated and the simulated results are qualitatively in good agreement with reported experimental results. Simulated results show that non-inverted and inverted 640 Gbit/s wavelength conversions based on NPR are achieved with clear open eye diagrams. To further investigate the performance of the non-inverted wavelength conversion scheme, the dependence of output extinction ratio (ER) on some key parameters used in simulation is illustrated. Furthermore, simulated analyses show that high performance non-inverted wavelength conversion based on NPR can be achieved by using a red-shifted filtering scheme.展开更多
The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . T...The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.展开更多
Color conversion glass ceramics are prepared by cosintering borosilicate glass frits and green 0.06Ce:Y2.94(Al1-xGax)5O12 phosphors. The crystal structures, the influence of Ga concentration on the photoluminescen...Color conversion glass ceramics are prepared by cosintering borosilicate glass frits and green 0.06Ce:Y2.94(Al1-xGax)5O12 phosphors. The crystal structures, the influence of Ga concentration on the photoluminescence (PL), and reliability properties of the color conversion glass ceramics are investigated. The PL emission wavelengths of 0.06Ce:Y2.94(Al1-xGax)5O12 glass ceramics show blue shift from 545 nm to 525 nm with increasing Ga content (x value) under excited at 460 nm. Reliability test results show that the quantum yield (QY) of 0.06Ce:Y2.94(Al1-xGax)5O12 glass ceramics decreases from 70.60% to 59.06% with x value increasing from 0.15 to 0.35 under the ambient condition of 85℃/RH85% for the exposure time of 168 h. And the quantum yield (QY) of 0.06Ce:Y2.94(Al1-xGax)5O12 glass ceramics decreases from 65.13% to 52.23% after being soaked into boiled water for 4 h. The finding reveals that the addition of Ga can deteriorate the reliability of the color conversion glass ceramics.展开更多
Broad-band all-optical wavelength conversion of differential phase-shift keyed (DPSK) signal is experimentally demonstrated. This scheme is composed of a one-bit delay interferometer demodulation stage followed by a...Broad-band all-optical wavelength conversion of differential phase-shift keyed (DPSK) signal is experimentally demonstrated. This scheme is composed of a one-bit delay interferometer demodulation stage followed by a semiconductor optical amplifier (SOA) based nonlinear polarization switch. A wavelength converter for the 10 G b/s DPSK signal is presented, which has a wide wavelength range of more than 30 nm. The converted signals experience small power penalties less than 1.4 dB compared with the original signal, at a bit error rate of 10-9. Additionally, the optical spectra, the measured waveforms and the open eye diagrams of the converted signals show a high quality wavelength conversion performance.展开更多
In current documented studies,it has been observed that wavelength converters utilizing AlGaAsOI waveguides exhibit suboptimal on-chip wavelength conversion efficiency from the C-band to the 2μm band,generally fallin...In current documented studies,it has been observed that wavelength converters utilizing AlGaAsOI waveguides exhibit suboptimal on-chip wavelength conversion efficiency from the C-band to the 2μm band,generally falling below−20.0 dB.To address this issue,we present a novel wavelength conversion device assisted by a waveguide amplifier,incorporating both AlGaAs wavelength converter and erbium-ytterbium co-doped waveguide amplifier,thereby achieving a notable conversion efficiency exceeding 0 dB.The noteworthy enhancement in efficiency can be attributed to the specific dispersion design of the AlGaAs wavelength converter,which enables an upsurge in conversion efficiency to−15.54 dB under 100 mW of pump power.Furthermore,the integration of an erbium-ytterbium co-doped waveguide amplifier facilitates a loss compensation of over 15 dB.Avoiding the use of external optical amplifiers,this device enables efficient and high-bandwidth wavelength conversion,showing promising applications in various fields,such as optical communication,sensing,imaging,and beyond.展开更多
In this paper, we propose a new multicast wavelength assignment algorithm called NGWA with complexity of O(N), where N is the number of nodes on a multicast tree. The whole procedure of NGWA algorithm is separated int...In this paper, we propose a new multicast wavelength assignment algorithm called NGWA with complexity of O(N), where N is the number of nodes on a multicast tree. The whole procedure of NGWA algorithm is separated into two phases: the partial wavelength assignment phase and the complete wavelength assignment phase. It tries to minimize the total number of wavelength conversions of the multicast tree. Meanwhile, the number of different wavelengths used is minimized locally. Through illustrative example and simulation experiments, it is proved that the NGWA algorithm works well and achieves satisfactory performance in terms of the average number of wavelength conversions and the average blocking probability.展开更多
Dynamic routing and wavelength assignment in the wavelength division multiplex optical networks with both dynamic service traffic and limited-range wavelength conversion have been discussed. Based on Moone-Dijkstra al...Dynamic routing and wavelength assignment in the wavelength division multiplex optical networks with both dynamic service traffic and limited-range wavelength conversion have been discussed. Based on Moone-Dijkstra algorithm, a novel heuristic dynamic min-cost & optimal virtual wavelength path (DMC-OVWP) algorithm is proposed, in which the probability and limitation of wavelength conversion are taken into account. With separation and combination of routing and wavelength assignment sub-problems, RWA problem is optimized. The simulation results for the topology like China Education and Research Network using the algorithm show that low blocking probability is obtained.展开更多
All-optical wavelength conversion of 10-Gb/s signal based on four-wave mixing is experimentally demonstrated in a 30-m-long dispersion-flattened microstructure fiber with small positive dispersion. For an average pump...All-optical wavelength conversion of 10-Gb/s signal based on four-wave mixing is experimentally demonstrated in a 30-m-long dispersion-flattened microstructure fiber with small positive dispersion. For an average pump power of 26 dBm, the conversion efficiency was around -19.5 dB with the fluctuation less than ±1.4 dB, covering a conversion bandwidth of 20 nm. The eye diagram of the converted signal shows good eye opening.展开更多
All-optical wavelength conversion has been demonstrated with an electroabsorption modulator based on cross-absorption modulation. For the first time, simultaneous broadcasting up to 6 different wavelengths at 10Gb/s i...All-optical wavelength conversion has been demonstrated with an electroabsorption modulator based on cross-absorption modulation. For the first time, simultaneous broadcasting up to 6 different wavelengths at 10Gb/s is obtained with less than 0.5-dB polarization dependence.展开更多
We investigated the all-optical wavelength conversion technique for non-return-to-zero(NRZ) signals based on a Sagnac loop interferometer using an SOA. For the wavelength conversion of the NRZ signal at and above40 ...We investigated the all-optical wavelength conversion technique for non-return-to-zero(NRZ) signals based on a Sagnac loop interferometer using an SOA. For the wavelength conversion of the NRZ signal at and above40 Gbit/s, we used an in-house numerical SOA model to analyze the influence of the SOA carrier characteristics and the SOA length on the performance of the Sagnac loop. We found that the SOA carrier recovery time should be between 2 and 3 times of one bit duration in order to get optimum NRZ wavelength conversion. In addition to the carrier recovery time requirement, SOAs with a shorter physical length are preferred to be used in the Sagnac interferometer.展开更多
A polarization-diversity loop with a silicon waveguide with a lateral p-i-n diode as a nonlinear medium is used to realize polarization insensitive four-wave mixing. Wavelength conversion of seven dual-polarization 16...A polarization-diversity loop with a silicon waveguide with a lateral p-i-n diode as a nonlinear medium is used to realize polarization insensitive four-wave mixing. Wavelength conversion of seven dual-polarization 16-quadrature amplitude modulation(QAM) signals at 16 GBd is demonstrated with an optical signal-to-noise ratio penalty below 0.7 dB. High-quality converted signals are generated thanks to the low polarization dependence(≤0.5 dB) and the high conversion efficiency(CE) achievable. The strong Kerr nonlinearity in silicon and the decrease of detrimental free-carrier absorption due to the reverse-biased p-i-n diode are key in ensuring high CE levels.展开更多
We numerically investigate four-wave-mixing (FWM) based multichannel wavelength conversion for amplitude-modulated signals, phase-modulated signals, together with mixed amplitude and phase modulated signals. This pa...We numerically investigate four-wave-mixing (FWM) based multichannel wavelength conversion for amplitude-modulated signals, phase-modulated signals, together with mixed amplitude and phase modulated signals. This paper also discusses the influence of stimulated Brillouin scattering (SBS) effects on high-efficiency FWM-based wavelength conversion applications. Our simulation results show that DPSK signals are more suitable for FWM-based multichannel wavelength conversion because the OOK signals will suffer from the inevitable data- pattern-dependent pump depletion. In future applications, when the modulation format is partially upgraded from OOK to DPSK, the influence of OOK signals on the updated DPSK signals must be considered when using multi-channel wavelength conversion. This influence becomes severe with the increase of OOK channel number. It can be concluded that DPSK signals are more appropriate for both transmission and multichannel wavelength conversion, especially in long haul and high bit-rate system.展开更多
Wavelength conversion based on degenerate four-wave mixing (FWM) was demonstrated and compared between silicon nanowire and microring resonator (MRR). 15 dB enhancement of conversion efficiency (CE) with relativ...Wavelength conversion based on degenerate four-wave mixing (FWM) was demonstrated and compared between silicon nanowire and microring resonator (MRR). 15 dB enhancement of conversion efficiency (CE) with relatively low input pump power (5roW) was achieved experimentally in an MRR. The impacts of bus waveguide length and propagation loss were theoretically analyzed under the effect of nonlinear loss.展开更多
In this paper, a new structure of highly nonlinear low dispersion photonic crystal fiber (HN- PCF) by elliptical concentration of GeO2 in the PCF core has been proposed. Using finite difference time domain (FDTD) ...In this paper, a new structure of highly nonlinear low dispersion photonic crystal fiber (HN- PCF) by elliptical concentration of GeO2 in the PCF core has been proposed. Using finite difference time domain (FDTD) method, we have analyzed the dispersion proper- ties and effective mode area in the HN-PCF. Simulative results show that the dispersion variation is within 4-0.65 ps/(nm.km) in C-band, especially 0.24ps/(nm.km) in 1.55 ~tm wavelength. Effective area and nonlinear coeffi- cient are 1.764pm2 and 72.6Wl"km-1 respectively at 1.55 ~tm wavelength. The proposed PCF demonstrates high nonlinear coefficient, ultra small effective mode area and nearly-zero flattened dispersion characteristics over C- band, which can have important application in all-optical wavelength conversion based on four wave mixing (FWM).展开更多
Differential quadrature phase shift keying (DQPSK) modulation is attractive in high-speed optical communications because of its resistance to fiber non-linearities and more efficient use of fiber bandwidth compared ...Differential quadrature phase shift keying (DQPSK) modulation is attractive in high-speed optical communications because of its resistance to fiber non-linearities and more efficient use of fiber bandwidth compared to conventional intensity modulation schemes. Because of its wavelength conversion ability and phase preservation, semiconductor optical amplifier (SOA) four- wave mixing (FWM) has attracted much attention. We experimentally study wavelength conversion of 40 Gbit/s (20 Gbaud) non-return-to-zero (NRZ)-DQPSK data using FWM in a quantum dash SOA with 20 dB gain and 5 dBm output saturation power. Q factor improvement and eye diagram reshaping is shown for up to 3 nm pump-probe detuning and is superior to that reported for a higher gain bulk SOA.展开更多
A dual-wavelength-injection-locked (DWIL) Fabry-Perot (FP) laser is used as an all-optical wavelength converter and regenerator. Regenerated pulses have narrower pulse-width of 37ps. Power penalty and extinction-ratio...A dual-wavelength-injection-locked (DWIL) Fabry-Perot (FP) laser is used as an all-optical wavelength converter and regenerator. Regenerated pulses have narrower pulse-width of 37ps. Power penalty and extinction-ratio improvement of 1.5dB and 4dB respectively were achieved.展开更多
Novel configuration for cross-gain modulation (XGM) wavelength conversion based on the single-port-coupled semiconductor optical amplifier (SOA), in which the input and the output share one port, has been demonstrated...Novel configuration for cross-gain modulation (XGM) wavelength conversion based on the single-port-coupled semiconductor optical amplifier (SOA), in which the input and the output share one port, has been demonstrated with the output extinction ratio as high as 15 dB, even in the 2.5 Gbit/s wavelength up conversion with a 12.8 nm span. Owing to the existence of double-pass gain and the transmission loss of the rear facet, the novel scheme can be achieved with simpler implementation and higher output extinction ratio, compared with the conventional schemes based on double-port-coupled SOA either with identical long chip or double long chip.展开更多
A wavelength filter with simple structure using multimode waveguide is proposed. The device uses mode conversion by a grating structure fabricated simultaneously with the multimode waveguide.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB632704)
文摘Tunable coherent emission is generated in a single-pass, cascaded wavelength conversion process from mode-locked laser-pumped monolithic periodically poled lithium niobate(PPLN). Three ranges of wavelength, including visible output from 628 nm to 639 nm, near-infrared output from 797 nm to 816 nm, and mid-infrared output from 3167 nm to 3459 nm,were obtained from the monolithic PPLN, which consists of a 10-mm section for 532-nm-pumped optical parametric generation(OPG) and a 7-mm section for 1064-nm-pumped sum frequency generation(SFG). A pump-to-signal conversion efficiency of 23.4% for OPG at 50°C and a quantum efficiency of 26.2% for SFG at 200°C were obtained.
基金Project supported by the Ministry of Education of China(Grant Nos105036 and NCET-04-0116)
文摘Taking into account ultra-fast carrier dynamics, this paper models 640 Gbit/s wavelength conversion scheme based on nonlinear polarization rotation (NPR) in a single semiconductor optical amplifier (SOA) and investigates the performance of this kind of wavelength conversion scheme in detail. In this model, two carrier temperature equations are introduced to substitute two energy density equations, which reduce the complexity of calculation in comparison with the previous model. The temporary gain and phase shift dynamics induced by ultra-short optical pulses are numerically simulated and the simulated results are qualitatively in good agreement with reported experimental results. Simulated results show that non-inverted and inverted 640 Gbit/s wavelength conversions based on NPR are achieved with clear open eye diagrams. To further investigate the performance of the non-inverted wavelength conversion scheme, the dependence of output extinction ratio (ER) on some key parameters used in simulation is illustrated. Furthermore, simulated analyses show that high performance non-inverted wavelength conversion based on NPR can be achieved by using a red-shifted filtering scheme.
基金Project(60632010) supported by the National Natural Science Foundation of China
文摘The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.
基金Project supported by the National Natural Science Foundation of China(Grant No.51302171)the Science and Technology Commission of Shanghai Municipality,China(Grant No.14500503300)the Natural Science Foundation of Shanghai,China(Grant No.12ZR1430900)
文摘Color conversion glass ceramics are prepared by cosintering borosilicate glass frits and green 0.06Ce:Y2.94(Al1-xGax)5O12 phosphors. The crystal structures, the influence of Ga concentration on the photoluminescence (PL), and reliability properties of the color conversion glass ceramics are investigated. The PL emission wavelengths of 0.06Ce:Y2.94(Al1-xGax)5O12 glass ceramics show blue shift from 545 nm to 525 nm with increasing Ga content (x value) under excited at 460 nm. Reliability test results show that the quantum yield (QY) of 0.06Ce:Y2.94(Al1-xGax)5O12 glass ceramics decreases from 70.60% to 59.06% with x value increasing from 0.15 to 0.35 under the ambient condition of 85℃/RH85% for the exposure time of 168 h. And the quantum yield (QY) of 0.06Ce:Y2.94(Al1-xGax)5O12 glass ceramics decreases from 65.13% to 52.23% after being soaked into boiled water for 4 h. The finding reveals that the addition of Ga can deteriorate the reliability of the color conversion glass ceramics.
文摘Broad-band all-optical wavelength conversion of differential phase-shift keyed (DPSK) signal is experimentally demonstrated. This scheme is composed of a one-bit delay interferometer demodulation stage followed by a semiconductor optical amplifier (SOA) based nonlinear polarization switch. A wavelength converter for the 10 G b/s DPSK signal is presented, which has a wide wavelength range of more than 30 nm. The converted signals experience small power penalties less than 1.4 dB compared with the original signal, at a bit error rate of 10-9. Additionally, the optical spectra, the measured waveforms and the open eye diagrams of the converted signals show a high quality wavelength conversion performance.
基金funded by the Key Program of the National Natural Science Foundation of China(Grant No.62035001)the International Partnership Program of Chinese Academy of Sciences(No.18123KYSB20210013)the Shanghai Science and Technology Innovation Action Plan(No.22dz208700).
文摘In current documented studies,it has been observed that wavelength converters utilizing AlGaAsOI waveguides exhibit suboptimal on-chip wavelength conversion efficiency from the C-band to the 2μm band,generally falling below−20.0 dB.To address this issue,we present a novel wavelength conversion device assisted by a waveguide amplifier,incorporating both AlGaAs wavelength converter and erbium-ytterbium co-doped waveguide amplifier,thereby achieving a notable conversion efficiency exceeding 0 dB.The noteworthy enhancement in efficiency can be attributed to the specific dispersion design of the AlGaAs wavelength converter,which enables an upsurge in conversion efficiency to−15.54 dB under 100 mW of pump power.Furthermore,the integration of an erbium-ytterbium co-doped waveguide amplifier facilitates a loss compensation of over 15 dB.Avoiding the use of external optical amplifiers,this device enables efficient and high-bandwidth wavelength conversion,showing promising applications in various fields,such as optical communication,sensing,imaging,and beyond.
文摘In this paper, we propose a new multicast wavelength assignment algorithm called NGWA with complexity of O(N), where N is the number of nodes on a multicast tree. The whole procedure of NGWA algorithm is separated into two phases: the partial wavelength assignment phase and the complete wavelength assignment phase. It tries to minimize the total number of wavelength conversions of the multicast tree. Meanwhile, the number of different wavelengths used is minimized locally. Through illustrative example and simulation experiments, it is proved that the NGWA algorithm works well and achieves satisfactory performance in terms of the average number of wavelength conversions and the average blocking probability.
基金Supported by National Science Foundation of China(No.60272048)
文摘Dynamic routing and wavelength assignment in the wavelength division multiplex optical networks with both dynamic service traffic and limited-range wavelength conversion have been discussed. Based on Moone-Dijkstra algorithm, a novel heuristic dynamic min-cost & optimal virtual wavelength path (DMC-OVWP) algorithm is proposed, in which the probability and limitation of wavelength conversion are taken into account. With separation and combination of routing and wavelength assignment sub-problems, RWA problem is optimized. The simulation results for the topology like China Education and Research Network using the algorithm show that low blocking probability is obtained.
基金This work was supported by the National Basic Research Program of China(No.2003CB314906)the Foundation for Key Program of Ministry of Education,P.R.China(No.104046).
文摘All-optical wavelength conversion of 10-Gb/s signal based on four-wave mixing is experimentally demonstrated in a 30-m-long dispersion-flattened microstructure fiber with small positive dispersion. For an average pump power of 26 dBm, the conversion efficiency was around -19.5 dB with the fluctuation less than ±1.4 dB, covering a conversion bandwidth of 20 nm. The eye diagram of the converted signal shows good eye opening.
文摘All-optical wavelength conversion has been demonstrated with an electroabsorption modulator based on cross-absorption modulation. For the first time, simultaneous broadcasting up to 6 different wavelengths at 10Gb/s is obtained with less than 0.5-dB polarization dependence.
基金Project supported by the Scientific Research Foundation of Nanjing University of Posts and Telecommunications(Nos.NY212008,213116)the National Science Foundation of Jiangsu Province(No.BK20131383)
文摘We investigated the all-optical wavelength conversion technique for non-return-to-zero(NRZ) signals based on a Sagnac loop interferometer using an SOA. For the wavelength conversion of the NRZ signal at and above40 Gbit/s, we used an in-house numerical SOA model to analyze the influence of the SOA carrier characteristics and the SOA length on the performance of the Sagnac loop. We found that the SOA carrier recovery time should be between 2 and 3 times of one bit duration in order to get optimum NRZ wavelength conversion. In addition to the carrier recovery time requirement, SOAs with a shorter physical length are preferred to be used in the Sagnac interferometer.
文摘A polarization-diversity loop with a silicon waveguide with a lateral p-i-n diode as a nonlinear medium is used to realize polarization insensitive four-wave mixing. Wavelength conversion of seven dual-polarization 16-quadrature amplitude modulation(QAM) signals at 16 GBd is demonstrated with an optical signal-to-noise ratio penalty below 0.7 dB. High-quality converted signals are generated thanks to the low polarization dependence(≤0.5 dB) and the high conversion efficiency(CE) achievable. The strong Kerr nonlinearity in silicon and the decrease of detrimental free-carrier absorption due to the reverse-biased p-i-n diode are key in ensuring high CE levels.
基金supported by the National Hi-Tech Research and Development Program of China(Nos.2006AA01Z253,2006AA01Z261)the National Natural Science Foundation of China(Nos.60877045,60736003)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Chinese Ministry of Education
文摘We numerically investigate four-wave-mixing (FWM) based multichannel wavelength conversion for amplitude-modulated signals, phase-modulated signals, together with mixed amplitude and phase modulated signals. This paper also discusses the influence of stimulated Brillouin scattering (SBS) effects on high-efficiency FWM-based wavelength conversion applications. Our simulation results show that DPSK signals are more suitable for FWM-based multichannel wavelength conversion because the OOK signals will suffer from the inevitable data- pattern-dependent pump depletion. In future applications, when the modulation format is partially upgraded from OOK to DPSK, the influence of OOK signals on the updated DPSK signals must be considered when using multi-channel wavelength conversion. This influence becomes severe with the increase of OOK channel number. It can be concluded that DPSK signals are more appropriate for both transmission and multichannel wavelength conversion, especially in long haul and high bit-rate system.
文摘Wavelength conversion based on degenerate four-wave mixing (FWM) was demonstrated and compared between silicon nanowire and microring resonator (MRR). 15 dB enhancement of conversion efficiency (CE) with relatively low input pump power (5roW) was achieved experimentally in an MRR. The impacts of bus waveguide length and propagation loss were theoretically analyzed under the effect of nonlinear loss.
文摘In this paper, a new structure of highly nonlinear low dispersion photonic crystal fiber (HN- PCF) by elliptical concentration of GeO2 in the PCF core has been proposed. Using finite difference time domain (FDTD) method, we have analyzed the dispersion proper- ties and effective mode area in the HN-PCF. Simulative results show that the dispersion variation is within 4-0.65 ps/(nm.km) in C-band, especially 0.24ps/(nm.km) in 1.55 ~tm wavelength. Effective area and nonlinear coeffi- cient are 1.764pm2 and 72.6Wl"km-1 respectively at 1.55 ~tm wavelength. The proposed PCF demonstrates high nonlinear coefficient, ultra small effective mode area and nearly-zero flattened dispersion characteristics over C- band, which can have important application in all-optical wavelength conversion based on four wave mixing (FWM).
基金Acknowledgements This research was supported by Science Foundation Ireland Investigator Grant 09/IN.1/I2641.
文摘Differential quadrature phase shift keying (DQPSK) modulation is attractive in high-speed optical communications because of its resistance to fiber non-linearities and more efficient use of fiber bandwidth compared to conventional intensity modulation schemes. Because of its wavelength conversion ability and phase preservation, semiconductor optical amplifier (SOA) four- wave mixing (FWM) has attracted much attention. We experimentally study wavelength conversion of 40 Gbit/s (20 Gbaud) non-return-to-zero (NRZ)-DQPSK data using FWM in a quantum dash SOA with 20 dB gain and 5 dBm output saturation power. Q factor improvement and eye diagram reshaping is shown for up to 3 nm pump-probe detuning and is superior to that reported for a higher gain bulk SOA.
文摘A dual-wavelength-injection-locked (DWIL) Fabry-Perot (FP) laser is used as an all-optical wavelength converter and regenerator. Regenerated pulses have narrower pulse-width of 37ps. Power penalty and extinction-ratio improvement of 1.5dB and 4dB respectively were achieved.
基金The authors would like to thank Dr. Zhang Zheming, Dr. Huang Gefan, Dr. Gong Wei and Dr. Fu Yan-feng at Wuhan Institute of Post and Telecommunication for their kind help This work was supported by the National High Technology Development Program of Chi
文摘Novel configuration for cross-gain modulation (XGM) wavelength conversion based on the single-port-coupled semiconductor optical amplifier (SOA), in which the input and the output share one port, has been demonstrated with the output extinction ratio as high as 15 dB, even in the 2.5 Gbit/s wavelength up conversion with a 12.8 nm span. Owing to the existence of double-pass gain and the transmission loss of the rear facet, the novel scheme can be achieved with simpler implementation and higher output extinction ratio, compared with the conventional schemes based on double-port-coupled SOA either with identical long chip or double long chip.
文摘A wavelength filter with simple structure using multimode waveguide is proposed. The device uses mode conversion by a grating structure fabricated simultaneously with the multimode waveguide.