We experimentally demonstrate the all-optical efficient technique for dynamic full-duplex wavelength routing and reach extension through adoption of passive fibre Bragg grating(FBG),energy efficient vertical cavity su...We experimentally demonstrate the all-optical efficient technique for dynamic full-duplex wavelength routing and reach extension through adoption of passive fibre Bragg grating(FBG),energy efficient vertical cavity surface emitting lasers(VCSELs)and high gain forward Raman pump.In this study,two VCSEL channels at 1549.62 nm and 1550.01 nm are directly modulated with a 8.5 Gbit/s data signal each,and transmitted over 25.5 km fibre to a passive single mode FBG-based wavelength routing node.The precise wavelength selectivity of the FBG is exploited to achieve all-optical real-time wavelength routing of the 1549.62 nm VCSEL channel with a maximum insertion loss of 22.1 dB.The 1550.01 nm channel is transmitted through the FBG with a maximum penalty of 1.03 dB.By utilizing the 7.2 dB flat gain of a forward Raman pump,the routed 1549.62 nm VCSEL channel is transmitted over 76.7 km fibre with a maximum penalty of 3.84 dB at bit error rate(BER)of 5-5.Our technique is all-optical,power efficient as it employs passive FBG and circulators and has low cross talk allied to precise wavelength selectivity of the technique.展开更多
An all-optical wavelength reuse technique employing cost effective power efficient vertical surface emitting laser(VCSEL) is proposed to address uplink data streaming from end-users by exploiting the same wavelength a...An all-optical wavelength reuse technique employing cost effective power efficient vertical surface emitting laser(VCSEL) is proposed to address uplink data streaming from end-users by exploiting the same wavelength assigned to them. A saturated optical erbium-doped optical fiber amplifier(EDFA) is adopted to erase a directly modulated 10 Gbit/s data from an incoming downstream wavelength. We show that with EDFA saturation, the extinction ration of the incoming wavelength is reduced to less than 1 d Bm, therefore allowing for wavelength re-modulation. A receiver sensitivity of -19.65 d Bm and -17.86 d Bm is attained for downstream and upstream data signals respectively. A total of 24.7 km single mode fibre transmission is attained experimentally. This technique opens new perspectives towards development of efficient spectrum utilization for application in wavelength flexible optical networks with non-static flex-spectrum grids.展开更多
We experimentally demonstrate the multiple signal modulation on a single class 10 G vertical cavity surface emitting laser(VCSEL) carrier at 1 310 nm for next generation multicast-enabled data center networks. A 10 Gb...We experimentally demonstrate the multiple signal modulation on a single class 10 G vertical cavity surface emitting laser(VCSEL) carrier at 1 310 nm for next generation multicast-enabled data center networks. A 10 Gbit/s data signal is directly modulated onto a single mode VCSEL carrier. To maximize carrier spectral efficiency, a 2 GHz reference frequency(RF) clock tone is simultaneously modulated on the VCSEL phase attribute. The inherent VCSEL orthogonal polarization bistability with changing bias current is further exploited in transmission of a polarization based pulse per second(PPS) timing clock signal. Therefore, we simultaneously transmit a 10 Gbit/s directly modulated data, 2 GHz phase modulated RF and a polarization-based PPS clock signals using a single mode 10 GHz bandwidth VCSEL carrier. It is the first time that a single class 10 G VCSEL carrier is reported to transmit a directly modulated data, phase modulated RF clock and polarization based PPS timing signal simultaneously in a single wavelength. A of G.652 single mode fibre(SMF) transmission over 3.21 km is experimentally attained. A receiver sensitivity of-15.60 dBm is experimentally obtained for the directly modulated 10 Gbit/s data signal. A 3.21-km-long SMF transmission introduces a penalty of 0.23 dB to the data signal. The contribution of a 2 GHz phase modulated RF and a polarization-based PPS clock signal to this penalty is found to be 0.03 dB. An RF single-side band(SSB) phase noise values of -82.36 dBc/Hz and -77.97 dBc/Hz are attained without and with simultaneous directly modulated data and polarization-based PPS clock signals respectively for a 3.21-km-long SMF transmission. This work provides an alternative efficient and cost effective technique for simultaneous high-speed multiple information transmission to different network nodes within a data center network through shared network infrastructure.展开更多
In this paper, a novel vertical cavity surface emitting laser(VCSEL) polarization modulation technique based on polarization switching due to thermal heating in a single transverse mode class 10 G VCSEL at 1 310 nm is...In this paper, a novel vertical cavity surface emitting laser(VCSEL) polarization modulation technique based on polarization switching due to thermal heating in a single transverse mode class 10 G VCSEL at 1 310 nm is demonstrated experimentally. The inherent orthogonal polarization switching of the VCSEL carrier with changing bias is exploited in the transmission of pulse-per-second(PPS) timing clock signal. Experimental results show that PPS pulse widths of 9.97 μs and 9.98 μs are measured for back-to-back analysis and over 3.21 km of G 652 urban fibre transmission, respectively. This work provides a novel alternative for adoption in optical frequency and time transfer applications.展开更多
Short-reach optical interconnects among massive serves in data centers have attracted extensive research recently. Increasing capacity, cost and power efficiency as well as wavelength switching between data center net...Short-reach optical interconnects among massive serves in data centers have attracted extensive research recently. Increasing capacity, cost and power efficiency as well as wavelength switching between data center network nodes are still key challenges for current optical interconnects. In this work, we experimentally demonstrate the real-time intermode optical wavelength switching technique, for high-speed wavelength flexible data center interconnects. A10 Gbit/s 1 550 nm single mode vertical cavity surface emitting laser(VCSEL) is optically injected and used to control a 10 Gbit/s multimode VCSEL carrier at 850 nm. Results show that a clearly open eye diagram is achieved at back-to-back analysis, implying a successful wavelength switch and error-free operation at 10 Gbit/s. A fully optical wavelength conversion of a multimode VCSEL operation at 850 nm using a single mode VCSEL subject to external optical injection at 1 550 nm is reported. This work opens new perspectives towards the development of a cost effective high-speed real-time inter-band wavelength switching technique between servers and network devices operating at different transmission windows at network nodes, for current and future optical interconnects.展开更多
In this paper, we propose and experimentally demonstrate a vertical cavity surface emitting laser(VCSEL)-based simultaneous 45.2 Gbit/s(2×22.6 Gbit/s) 4-PAM data and 8 GHz(2×4 GHz) phase modulated reference ...In this paper, we propose and experimentally demonstrate a vertical cavity surface emitting laser(VCSEL)-based simultaneous 45.2 Gbit/s(2×22.6 Gbit/s) 4-PAM data and 8 GHz(2×4 GHz) phase modulated reference frequency(RF) clock signal transmission dense wavelength division multiplexing(DWDM) system for optical interconnects. Two low-cost power-efficient 10 G VCSEL channels with central wavelengths at 1 550.71 nm and 1 551.11 nm are separately modulated with 22.6 Gbit/s 4-PAM data, therefore doubling the channel bit rate. Carrier spectral efficiency per channel is further maximized by exploiting the phase attribute in transmission of a 4 Hz RF clock signal. To further maximize the network capacity, the two VCSEL channels are densely multiplexed at 0.4 nm spacing. We therefore experimentally achieve the network data rate of 45.2 Gbit/s with 8 GHz phase modulated RF clock signal. The results show that receiver sensitivities of-11.02 dBm and-9.98 dBm are experimentally achieved for VCSEL channels of 1 550.71 nm and 1 551.11 nm respectively without the phase modulated RF clock signal. However, the introduction of a phase modulated clock signal contributes to a maximum interference penalty of 0.57 dBm and 0.41 dBm for the considered channels respectively. Simultaneous distribution of transmission data and reference clock signal over shared network structure maximizes the carrier spectral efficiency and network capacity with low cost.展开更多
This paper experimentally demonstrates a low-cost energy efficient alternative technique for long reach transfer of accurate reference frequency(RF) clock signals for extended reach RF distribution systems.This is ach...This paper experimentally demonstrates a low-cost energy efficient alternative technique for long reach transfer of accurate reference frequency(RF) clock signals for extended reach RF distribution systems.This is achieved by adopting distributed forward Raman amplification and vertical cavity surface emitting laser(VCSEL) technology.A class 10 G VCSEL is directly modulated with a 2 GHz RF clock signal.By exploiting a forward Raman pump with the flat gain of 8.6 dB, a 100.8-km-long standard single mode fiber(SMF) RF clock distribution is experimentally achieved.A maximum phase noise of-117.66 dBc/Hz at offset frequency of 100 kHz and an RF clock jitter(RMS) of 5.36 ps is experimentally measured for 100.8-km-long fiber transmission without forward Raman amplification.However, with the adoption of forward Raman amplification, the measured phase noise and RMS improves to-86.59 dBc/Hz and 1.7 ps, respectively.Forward Raman pumping offers distributed high flat gain over a wide spectra range(over 35.5 nm), while VCSELs offer cost effective broadband signal distribution, therefore keeping the network optics investment low.展开更多
In this work, inherent data-erasing functionality of a saturated erbium doped fibre amplifier(EDFA) is exploited to achieve an all-optical wavelength reuse with pulse amplitude modulation(PAM) format. A 10 GHz bandwid...In this work, inherent data-erasing functionality of a saturated erbium doped fibre amplifier(EDFA) is exploited to achieve an all-optical wavelength reuse with pulse amplitude modulation(PAM) format. A 10 GHz bandwidth distributed feedback laser(DFB) is directly modulated with 17 Gbit/s PAM-3 data signal and transmitted downstream over a 26.58 km fibre optical line terminal(OLT) incurring a maximum penalty of 1.81 d B. A saturated EDFA deployed at the optical network unit(ONU) terminal is utilized to optically suppress the extinction ratio of residual 17 Gbit/s PAM-3 downstream data significantly from 7.1 d B to 830 md B. This facilitates direct reuse of the downstream carrier without the need for an additional electrical data eraser. With the all optical data erasing capability of EDFA over-10 d Bm input power, the carrier re-used upstream transmission successfully delivers 17 Gbit/s PAM-3 data with a maximum transmission penalty of 0.99 d B. PAM-3 modulation format maximizes network efficiency by doubling the transmitted bits per symbol. Our technique is all-optical, it can support ultrafast systems with higher modulation formats and is power efficient.展开更多
Accurate time transfer and synchronization between different network nodes is a key functional requirement in digital communication. Developments in optical fiber-based frequency dissemination techniques have improved...Accurate time transfer and synchronization between different network nodes is a key functional requirement in digital communication. Developments in optical fiber-based frequency dissemination techniques have improved optical frequency stability over time to much lower levels. In this work, we experimentally present the reference frequency transfer employing 850 nm vertical cavity surface emitting laser(VCSEL) over 100.3 m OM3 multimode fiber for synchronization of clocks on networked devices such as servers and racks/pod at different data center network nodes. A low-cost power-efficient multimode VCSEL with central wavelength at 844.26 nm is directly modulated with a 2 GHz reference frequency(RF) clock signal, and transferred over 100.3 m of OM3 multimode fiber. The single side band(SSB) phase noise of-104.62 dBc/Hz and-100.70 dBc/Hz is experimentally measured at back-to-back(B2 B) and 100.3 m OM3 multimode fiber transmission respectively at a 1 kHz frequency offset. The jitter stability of 0.14 ps and 0.15 ps is experimentally achieved at B2 B and 100.3 m fiber transmission, respectively. This work provides an alternative viable approach for the development of time keeping devices in high-speed short-reach optical communication systems.展开更多
文摘We experimentally demonstrate the all-optical efficient technique for dynamic full-duplex wavelength routing and reach extension through adoption of passive fibre Bragg grating(FBG),energy efficient vertical cavity surface emitting lasers(VCSELs)and high gain forward Raman pump.In this study,two VCSEL channels at 1549.62 nm and 1550.01 nm are directly modulated with a 8.5 Gbit/s data signal each,and transmitted over 25.5 km fibre to a passive single mode FBG-based wavelength routing node.The precise wavelength selectivity of the FBG is exploited to achieve all-optical real-time wavelength routing of the 1549.62 nm VCSEL channel with a maximum insertion loss of 22.1 dB.The 1550.01 nm channel is transmitted through the FBG with a maximum penalty of 1.03 dB.By utilizing the 7.2 dB flat gain of a forward Raman pump,the routed 1549.62 nm VCSEL channel is transmitted over 76.7 km fibre with a maximum penalty of 3.84 dB at bit error rate(BER)of 5-5.Our technique is all-optical,power efficient as it employs passive FBG and circulators and has low cross talk allied to precise wavelength selectivity of the technique.
文摘An all-optical wavelength reuse technique employing cost effective power efficient vertical surface emitting laser(VCSEL) is proposed to address uplink data streaming from end-users by exploiting the same wavelength assigned to them. A saturated optical erbium-doped optical fiber amplifier(EDFA) is adopted to erase a directly modulated 10 Gbit/s data from an incoming downstream wavelength. We show that with EDFA saturation, the extinction ration of the incoming wavelength is reduced to less than 1 d Bm, therefore allowing for wavelength re-modulation. A receiver sensitivity of -19.65 d Bm and -17.86 d Bm is attained for downstream and upstream data signals respectively. A total of 24.7 km single mode fibre transmission is attained experimentally. This technique opens new perspectives towards development of efficient spectrum utilization for application in wavelength flexible optical networks with non-static flex-spectrum grids.
文摘We experimentally demonstrate the multiple signal modulation on a single class 10 G vertical cavity surface emitting laser(VCSEL) carrier at 1 310 nm for next generation multicast-enabled data center networks. A 10 Gbit/s data signal is directly modulated onto a single mode VCSEL carrier. To maximize carrier spectral efficiency, a 2 GHz reference frequency(RF) clock tone is simultaneously modulated on the VCSEL phase attribute. The inherent VCSEL orthogonal polarization bistability with changing bias current is further exploited in transmission of a polarization based pulse per second(PPS) timing clock signal. Therefore, we simultaneously transmit a 10 Gbit/s directly modulated data, 2 GHz phase modulated RF and a polarization-based PPS clock signals using a single mode 10 GHz bandwidth VCSEL carrier. It is the first time that a single class 10 G VCSEL carrier is reported to transmit a directly modulated data, phase modulated RF clock and polarization based PPS timing signal simultaneously in a single wavelength. A of G.652 single mode fibre(SMF) transmission over 3.21 km is experimentally attained. A receiver sensitivity of-15.60 dBm is experimentally obtained for the directly modulated 10 Gbit/s data signal. A 3.21-km-long SMF transmission introduces a penalty of 0.23 dB to the data signal. The contribution of a 2 GHz phase modulated RF and a polarization-based PPS clock signal to this penalty is found to be 0.03 dB. An RF single-side band(SSB) phase noise values of -82.36 dBc/Hz and -77.97 dBc/Hz are attained without and with simultaneous directly modulated data and polarization-based PPS clock signals respectively for a 3.21-km-long SMF transmission. This work provides an alternative efficient and cost effective technique for simultaneous high-speed multiple information transmission to different network nodes within a data center network through shared network infrastructure.
文摘In this paper, a novel vertical cavity surface emitting laser(VCSEL) polarization modulation technique based on polarization switching due to thermal heating in a single transverse mode class 10 G VCSEL at 1 310 nm is demonstrated experimentally. The inherent orthogonal polarization switching of the VCSEL carrier with changing bias is exploited in the transmission of pulse-per-second(PPS) timing clock signal. Experimental results show that PPS pulse widths of 9.97 μs and 9.98 μs are measured for back-to-back analysis and over 3.21 km of G 652 urban fibre transmission, respectively. This work provides a novel alternative for adoption in optical frequency and time transfer applications.
文摘Short-reach optical interconnects among massive serves in data centers have attracted extensive research recently. Increasing capacity, cost and power efficiency as well as wavelength switching between data center network nodes are still key challenges for current optical interconnects. In this work, we experimentally demonstrate the real-time intermode optical wavelength switching technique, for high-speed wavelength flexible data center interconnects. A10 Gbit/s 1 550 nm single mode vertical cavity surface emitting laser(VCSEL) is optically injected and used to control a 10 Gbit/s multimode VCSEL carrier at 850 nm. Results show that a clearly open eye diagram is achieved at back-to-back analysis, implying a successful wavelength switch and error-free operation at 10 Gbit/s. A fully optical wavelength conversion of a multimode VCSEL operation at 850 nm using a single mode VCSEL subject to external optical injection at 1 550 nm is reported. This work opens new perspectives towards the development of a cost effective high-speed real-time inter-band wavelength switching technique between servers and network devices operating at different transmission windows at network nodes, for current and future optical interconnects.
文摘In this paper, we propose and experimentally demonstrate a vertical cavity surface emitting laser(VCSEL)-based simultaneous 45.2 Gbit/s(2×22.6 Gbit/s) 4-PAM data and 8 GHz(2×4 GHz) phase modulated reference frequency(RF) clock signal transmission dense wavelength division multiplexing(DWDM) system for optical interconnects. Two low-cost power-efficient 10 G VCSEL channels with central wavelengths at 1 550.71 nm and 1 551.11 nm are separately modulated with 22.6 Gbit/s 4-PAM data, therefore doubling the channel bit rate. Carrier spectral efficiency per channel is further maximized by exploiting the phase attribute in transmission of a 4 Hz RF clock signal. To further maximize the network capacity, the two VCSEL channels are densely multiplexed at 0.4 nm spacing. We therefore experimentally achieve the network data rate of 45.2 Gbit/s with 8 GHz phase modulated RF clock signal. The results show that receiver sensitivities of-11.02 dBm and-9.98 dBm are experimentally achieved for VCSEL channels of 1 550.71 nm and 1 551.11 nm respectively without the phase modulated RF clock signal. However, the introduction of a phase modulated clock signal contributes to a maximum interference penalty of 0.57 dBm and 0.41 dBm for the considered channels respectively. Simultaneous distribution of transmission data and reference clock signal over shared network structure maximizes the carrier spectral efficiency and network capacity with low cost.
文摘This paper experimentally demonstrates a low-cost energy efficient alternative technique for long reach transfer of accurate reference frequency(RF) clock signals for extended reach RF distribution systems.This is achieved by adopting distributed forward Raman amplification and vertical cavity surface emitting laser(VCSEL) technology.A class 10 G VCSEL is directly modulated with a 2 GHz RF clock signal.By exploiting a forward Raman pump with the flat gain of 8.6 dB, a 100.8-km-long standard single mode fiber(SMF) RF clock distribution is experimentally achieved.A maximum phase noise of-117.66 dBc/Hz at offset frequency of 100 kHz and an RF clock jitter(RMS) of 5.36 ps is experimentally measured for 100.8-km-long fiber transmission without forward Raman amplification.However, with the adoption of forward Raman amplification, the measured phase noise and RMS improves to-86.59 dBc/Hz and 1.7 ps, respectively.Forward Raman pumping offers distributed high flat gain over a wide spectra range(over 35.5 nm), while VCSELs offer cost effective broadband signal distribution, therefore keeping the network optics investment low.
文摘In this work, inherent data-erasing functionality of a saturated erbium doped fibre amplifier(EDFA) is exploited to achieve an all-optical wavelength reuse with pulse amplitude modulation(PAM) format. A 10 GHz bandwidth distributed feedback laser(DFB) is directly modulated with 17 Gbit/s PAM-3 data signal and transmitted downstream over a 26.58 km fibre optical line terminal(OLT) incurring a maximum penalty of 1.81 d B. A saturated EDFA deployed at the optical network unit(ONU) terminal is utilized to optically suppress the extinction ratio of residual 17 Gbit/s PAM-3 downstream data significantly from 7.1 d B to 830 md B. This facilitates direct reuse of the downstream carrier without the need for an additional electrical data eraser. With the all optical data erasing capability of EDFA over-10 d Bm input power, the carrier re-used upstream transmission successfully delivers 17 Gbit/s PAM-3 data with a maximum transmission penalty of 0.99 d B. PAM-3 modulation format maximizes network efficiency by doubling the transmitted bits per symbol. Our technique is all-optical, it can support ultrafast systems with higher modulation formats and is power efficient.
文摘Accurate time transfer and synchronization between different network nodes is a key functional requirement in digital communication. Developments in optical fiber-based frequency dissemination techniques have improved optical frequency stability over time to much lower levels. In this work, we experimentally present the reference frequency transfer employing 850 nm vertical cavity surface emitting laser(VCSEL) over 100.3 m OM3 multimode fiber for synchronization of clocks on networked devices such as servers and racks/pod at different data center network nodes. A low-cost power-efficient multimode VCSEL with central wavelength at 844.26 nm is directly modulated with a 2 GHz reference frequency(RF) clock signal, and transferred over 100.3 m of OM3 multimode fiber. The single side band(SSB) phase noise of-104.62 dBc/Hz and-100.70 dBc/Hz is experimentally measured at back-to-back(B2 B) and 100.3 m OM3 multimode fiber transmission respectively at a 1 kHz frequency offset. The jitter stability of 0.14 ps and 0.15 ps is experimentally achieved at B2 B and 100.3 m fiber transmission, respectively. This work provides an alternative viable approach for the development of time keeping devices in high-speed short-reach optical communication systems.
