Research Interests:
Research Interests:
Wireless transmission of unmodulated 28, 38, and 60GHz millimeter-wave (MMW) sub-carriers, generated by L-band quantum-dash laser-based comb-source, is investigated in terms of RF-characteristics. Low-frequency MMWs showcased ~4 to 5dB/m... more
Wireless transmission of unmodulated 28, 38, and 60GHz millimeter-wave (MMW) sub-carriers, generated by L-band quantum-dash laser-based comb-source, is investigated in terms of RF-characteristics. Low-frequency MMWs showcased ~4 to 5dB/m power-attenuation and ~−2 to −3dBc/Hz/m phase-noise degradation, while the 60GHz signal exhibited twice these values.
Research Interests:
Wireless transmission of unmodulated 28, 38, and 60GHz millimeter-wave (MMW) sub-carriers, generated by L-band quantum-dash laser-based comb-source, is investigated in terms of RF-characteristics. Low-frequency MMWs showcased ~4 to 5dB/m... more
Wireless transmission of unmodulated 28, 38, and 60GHz millimeter-wave (MMW) sub-carriers, generated by L-band quantum-dash laser-based comb-source, is investigated in terms of RF-characteristics. Low-frequency MMWs showcased ~4 to 5dB/m power-attenuation and ~−2 to −3dBc/Hz/m phase-noise degradation, while the 60GHz signal exhibited twice these values.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Effect of DP-QPSK modulation (28GBaud) and transmission on RF-characteristics is investigated for a 3-channel multiplexed system employing InAs/InP quantum-dash laser comb-source showing 3dB-bandwidth increase by ~16.7%, linewidth by ~7... more
Effect of DP-QPSK modulation (28GBaud) and transmission on RF-characteristics is investigated for a 3-channel multiplexed system employing InAs/InP quantum-dash laser comb-source showing 3dB-bandwidth increase by ~16.7%, linewidth by ~7 kHz, and phase-noise by ~4.7 dBc/Hz.
Research Interests:
Effect of DP-QPSK modulation (28GBaud) and transmission on RF-characteristics is investigated for a 3-channel multiplexed system employing InAs/InP quantum-dash laser comb-source showing 3dB-bandwidth increase by ~16.7%, linewidth by ~7... more
Effect of DP-QPSK modulation (28GBaud) and transmission on RF-characteristics is investigated for a 3-channel multiplexed system employing InAs/InP quantum-dash laser comb-source showing 3dB-bandwidth increase by ~16.7%, linewidth by ~7 kHz, and phase-noise by ~4.7 dBc/Hz.
Research Interests:
An indoor 100 Gb/s wireless communication is demonstrated using external coherent injection-locking of InAs/InP Quantum-dash (QDash) laser. Receiver power sensitivities of −18.4 dBm and −17.4 dBm at ∼1621.3 nm are observed after... more
An indoor 100 Gb/s wireless communication is demonstrated using external coherent injection-locking of InAs/InP Quantum-dash (QDash) laser. Receiver power sensitivities of −18.4 dBm and −17.4 dBm at ∼1621.3 nm are observed after propagating along a 2 m and 4 m indoor free-space channels, respectively, while adopting dual polarization quadrature phase shift keying (DP-QPSK) modulation scheme. Moreover, characterization of this far L-band QDash laser showed an injection locked Fabry-Perot mode tunability of ∼19 nm with > 35 dB side-mode-suppression-ratio. To the authors' knowledge, this is the first demonstration of showcasing QDash lasers as a viable candidate in optical wireless communication, an attractive alternate optical access technology for next generation high capacity networks.
Research Interests:
An indoor 100 Gb/s wireless communication is demonstrated using external coherent injection-locking of InAs/InP Quantum-dash (QDash) laser. Receiver power sensitivities of −18.4 dBm and −17.4 dBm at ∼1621.3 nm are observed after... more
An indoor 100 Gb/s wireless communication is demonstrated using external coherent injection-locking of InAs/InP Quantum-dash (QDash) laser. Receiver power sensitivities of −18.4 dBm and −17.4 dBm at ∼1621.3 nm are observed after propagating along a 2 m and 4 m indoor free-space channels, respectively, while adopting dual polarization quadrature phase shift keying (DP-QPSK) modulation scheme. Moreover, characterization of this far L-band QDash laser showed an injection locked Fabry-Perot mode tunability of ∼19 nm with > 35 dB side-mode-suppression-ratio. To the authors' knowledge, this is the first demonstration of showcasing QDash lasers as a viable candidate in optical wireless communication, an attractive alternate optical access technology for next generation high capacity networks.
Research Interests:
In this paper, we experimentally investigate the effect of state-of-the-art digital to analog converter (DAC) circuit, on the performance of high speed optical transmitter. We particularly consider two operating regimes, we refers as... more
In this paper, we experimentally investigate the effect of state-of-the-art digital to analog converter (DAC) circuit, on the performance of high speed optical transmitter. We particularly consider two operating regimes, we refers as over- and under-sampling conditions. It is well known that a sampling rate of 64GSa/s limits the maximum baud rate to 32Gbaud with a sampling rate of 2 sample/symbol as a standard oversampling. However, in a number of applications including test, characterization, and measurement of advanced communication systems, it is needed to test the capacity to use the hardware well above its normal operation regime. One important, yet attractive testing, is to examine the behavior of an overall communication system or its subsystems in case of 2-fold criterion is not respected. In these cases, the optical transmitter is constrained to generate and transmit optical symbols at a baud rate that is much higher than the half of the hardware limited sampling rate. In our case, we generate variable baud rates higher than 32Gbaud using an always fixed sampling rate 64GSa/s (i.e. limited by hardware). We hence constrain our symbols to be generated by less than 2 samples/symbol we refer as under sampling regime. Our experimental results show that in under sampling regime, we obtain a variable baud rate ranging from 32 up to 56Gbaud using a sampling ratio starting by 2 and decreasing down to 1.14 respectively. In addition we show, how these high and variable baud rates, have been achieved at the expense of much larger spectral bandwidth, important signal distortions especially for the highest frequency band, and a net decrease in the modulation order from 128 down to 4. We also investigate the performance of the generated signals in terms of bit error rate (BER) and error vector magnitude (EVM) and illustrate how the performance dramatically degrades as the sampling rate decreases. Furthermore, we digitally pre-emphasize the DP-MQAM Optical transmitter in order to pre-compensate for devices imperfections. This relaxes the signal processing at the receiver side at a maximum expense of 1dB penalty for 32Gbaud speed.
Research Interests:
In this paper, we experimentally investigate the effect of state-of-the-art digital to analog converter (DAC) circuit, on the performance of high speed optical transmitter. We particularly consider two operating regimes, we refers as... more
In this paper, we experimentally investigate the effect of state-of-the-art digital to analog converter (DAC) circuit, on the performance of high speed optical transmitter. We particularly consider two operating regimes, we refers as over- and under-sampling conditions. It is well known that a sampling rate of 64GSa/s limits the maximum baud rate to 32Gbaud with a sampling rate of 2 sample/symbol as a standard oversampling. However, in a number of applications including test, characterization, and measurement of advanced communication systems, it is needed to test the capacity to use the hardware well above its normal operation regime. One important, yet attractive testing, is to examine the behavior of an overall communication system or its subsystems in case of 2-fold criterion is not respected. In these cases, the optical transmitter is constrained to generate and transmit optical symbols at a baud rate that is much higher than the half of the hardware limited sampling rate. In our case, we generate variable baud rates higher than 32Gbaud using an always fixed sampling rate 64GSa/s (i.e. limited by hardware). We hence constrain our symbols to be generated by less than 2 samples/symbol we refer as under sampling regime. Our experimental results show that in under sampling regime, we obtain a variable baud rate ranging from 32 up to 56Gbaud using a sampling ratio starting by 2 and decreasing down to 1.14 respectively. In addition we show, how these high and variable baud rates, have been achieved at the expense of much larger spectral bandwidth, important signal distortions especially for the highest frequency band, and a net decrease in the modulation order from 128 down to 4. We also investigate the performance of the generated signals in terms of bit error rate (BER) and error vector magnitude (EVM) and illustrate how the performance dramatically degrades as the sampling rate decreases. Furthermore, we digitally pre-emphasize the DP-MQAM Optical transmitter in order to pre-compensate for devices imperfections. This relaxes the signal processing at the receiver side at a maximum expense of 1dB penalty for 32Gbaud speed.
Research Interests:
Research Interests:
Research Interests:
Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a... more
Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a potential candidate for last mile bottle neck in wireless network and for many other applications. In this paper, we experimentally demonstrate a high speed FSO system using super-channel source and multi-format transmitter. The FSO system was installed outdoor on the building roof over 11.5 m distance and built using off-the-shelf components. We designed a comb source capable of generating multi-subcarriers with flexible spacing. Also we designed a multi-format transmitter capable of generating different complex modulation schemes. For single carrier transmission, we were able to transmit a 23 Gbaud 16-QAM signal over FSO link, achieving 320 Gbps with 6 b/s/Hz spectral efficiency. Then using our super-channel system, 12 equal gain subcarriers are generated and modulated by a DP-16QAM signal with different symbol rates. We achieved maximum symbol rate of 23 Gbaud (i.e. 2.2 Tbps) and spectral efficiency of 7.2 b/s/Hz.
Research Interests:
Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a... more
Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a potential candidate for last mile bottle neck in wireless network and for many other applications. In this paper, we experimentally demonstrate a high speed FSO system using super-channel source and multi-format transmitter. The FSO system was installed outdoor on the building roof over 11.5 m distance and built using off-the-shelf components. We designed a comb source capable of generating multi-subcarriers with flexible spacing. Also we designed a multi-format transmitter capable of generating different complex modulation schemes. For single carrier transmission, we were able to transmit a 23 Gbaud 16-QAM signal over FSO link, achieving 320 Gbps with 6 b/s/Hz spectral efficiency. Then using our super-channel system, 12 equal gain subcarriers are generated and modulated by a DP-16QAM signal with different symbol rates. We achieved maximum symbol rate of 23 Gbaud (i.e. 2.2 Tbps) and spectral efficiency of 7.2 b/s/Hz.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Demonstration of mid-L-band (∼1602-1613nm) broadly tunable self-injection locked quantum-dash laser diode is reported with ∼11nm tunability and ∼30dB SMSR. Record 168(176) Gb/s DP-QPSK transmission over 10km SMF (16m FSO) link is achieved... more
Demonstration of mid-L-band (∼1602-1613nm) broadly tunable self-injection locked quantum-dash laser diode is reported with ∼11nm tunability and ∼30dB SMSR. Record 168(176) Gb/s DP-QPSK transmission over 10km SMF (16m FSO) link is achieved at ∼1610nm.
Research Interests:
Demonstration of mid-L-band (∼1602-1613nm) broadly tunable self-injection locked quantum-dash laser diode is reported with ∼11nm tunability and ∼30dB SMSR. Record 168(176) Gb/s DP-QPSK transmission over 10km SMF (16m FSO) link is achieved... more
Demonstration of mid-L-band (∼1602-1613nm) broadly tunable self-injection locked quantum-dash laser diode is reported with ∼11nm tunability and ∼30dB SMSR. Record 168(176) Gb/s DP-QPSK transmission over 10km SMF (16m FSO) link is achieved at ∼1610nm.
Research Interests:
Research Interests:
Generation of tunable millimeter-wave signals with frequencies 60, 38, and 28 GHz are reported from an injection-locked InAs/InP quantum-dash-laser emitting in L-band, for the first time. High performance with small-linewidths and... more
Generation of tunable millimeter-wave signals with frequencies 60, 38, and 28 GHz are reported from an injection-locked InAs/InP quantum-dash-laser emitting in L-band, for the first time. High performance with small-linewidths and phase-noise are demonstrated.
Research Interests:
Research Interests:
Injection locking is employed to lock two independent longitudinal modes of an L-band quantum-dash laser, thus generating a Terahertz photonic signal with a beat frequency of 1.2 THz.
Research Interests:
Research Interests:
Research Interests:
Efficient bit transmission, flexible spectrum utilization, polarization and space division multiplexing (PDM and SDM), and advanced laser designs are among the recent technologies adopted for boosting the capacity and spectral efficiency... more
Efficient bit transmission, flexible spectrum utilization, polarization and space division multiplexing (PDM and SDM), and advanced laser designs are among the recent technologies adopted for boosting the capacity and spectral efficiency (SE) of optical communication networks. In addition, all-optical wavelength conversion is required to reduce network latency and energy consumption. In this paper, we exploit the modulation and polarization transparency features of the semiconductor optical amplifiers (SOAs) in order to build a photonics-based wavelength converter for single and super-channel quadrature phase shift keying (QPSK)-PDM signals. An experimental demonstration is conducted and high transmission speeds are achieved including 18-, 20-, and 25-Gbaud. The experimental results show a conversion of a super-channel signal consisting of three dual-polarization QPSK signals with 216-Gbps total aggregated data rate using a co-propagated pump four-wave mixing (FWM) configuration.
Research Interests:
Injection locking is employed to lock two independent longitudinal modes of an L-band quantum-dash laser, thus generating a Terahertz photonic signal with a beat frequency of 1.2 THz.
Research Interests:
Research Interests:
Research Interests:
We demonstrate 128 and 176 Gb/s class DP-QPSK optical wireless communication system over 5 m indoor channel based on a novel tunable self-seeded InAs/InP quantum-dash laser diode at ∼1607 nm.
Research Interests:
We demonstrate an externally modulated single channel 64 Gbit/s DP-QPSK transmission based on injectionlocked Fabry-Pérot broadband quantum-dash laser at far L-band ~1621 nm wavelength. A receiver sensitivity of -16.7 dBm has been... more
We demonstrate an externally modulated single channel 64 Gbit/s DP-QPSK transmission based on injectionlocked Fabry-Pérot broadband quantum-dash laser at far L-band ~1621 nm wavelength. A receiver sensitivity of -16.7 dBm has been observed after 10 km SMF transmission, with power penalty of ~2 dB, under the FEC threshold. We also propose that these novel quantum-dash laser diode could be a route towards next generation 100Gbit-PONs as a unified upstream and downstream transmitters.
Research Interests:
Self-injection Locking is employed on L-band InAs/InP quantum-dash laser to lock a single Fabry-Perot mode with ∼9dBm power and >30dB SMSR. Successful 128 Gbit/s DP-QPSK data transmission is demonstrated via this ∼1607nm locked mode... more
Self-injection Locking is employed on L-band InAs/InP quantum-dash laser to lock a single Fabry-Perot mode with ∼9dBm power and >30dB SMSR. Successful 128 Gbit/s DP-QPSK data transmission is demonstrated via this ∼1607nm locked mode over a 10m indoor FSO channel exhibiting ∼-17.5dBm receiver-sensitivity.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
f, S growth of PONs (supporting more customers per fiber with higher data rates and better quality of service) increases b i
Research Interests:
A novel weakly guiding multimode fiber (MMF) with enhanced performance, named inverse hyperbolic tangent MMF (IHTAN MMF), is proposed and designed to exhibit larger separation ( ${\geq }1\times 10\,\,^{\mathrm{ -4}}$ ) within 14 mode... more
A novel weakly guiding multimode fiber (MMF) with enhanced performance, named inverse hyperbolic tangent MMF (IHTAN MMF), is proposed and designed to exhibit larger separation ( ${\geq }1\times 10\,\,^{\mathrm{ -4}}$ ) within 14 mode groups (MGs). This ensures improved available data channels compared with standard graded-index MMF and various recent orbital angular momentum (OAM) fibers, thus enabling a transmission free of multiple-input/multiple-output (MIMO). A numerical study of the key characteristics and performance metrics of the proposed IHTAN MMF is performed. The modal analysis shows a large separation between the supported MGs, thereby enabling low inter-channel crosstalk (XT) and enhanced OAM mode purities (99.9%). Consequently, resistivity to intrinsic XT is enhanced (−30 dB). Low differential intergroup and intragroup delays and flat and low chromatic dispersion are analyzed (proved), discussed, and compared with those of recent fibers. Comparison findings show that IHTAN MMF could play a role in short- or medium-haul MG multiplexing communications free of MIMO digital signal processing (DSP). Finally, the multiplexing, transmission, and demultiplexing system of 50 OAM data channels collocated with small, cost-effective, energy-efficient MIMO DSP blocks are discussed to enhance the scalability of the proposed fiber. The results show that IHTAN MMF could be a promising candidate for next-generation MMF-enabled OAM transmission systems.
Research Interests:
Research Interests:
Injection locked quantum-dash laser diode-based frequency-comb source is employed in wavelength-division multiplexed (WDM) transmission in ~1610nm L-band. An aggregate data rate of 192 Gbits/s (3×16 GBaud-DP-QPSK) is demonstrated over... more
Injection locked quantum-dash laser diode-based frequency-comb source is employed in wavelength-division multiplexed (WDM) transmission in ~1610nm L-band. An aggregate data rate of 192 Gbits/s (3×16 GBaud-DP-QPSK) is demonstrated over three channels separated by 50 GHz in coherent transmission over a 10 km-long single-mode fiber.
Research Interests:
Extensive channel data rate, high spectral efficiency, and advanced digital signal processing using state-of-the-art electronics are the main features for next generation optical networks. These technologies are complementary integrated... more
Extensive channel data rate, high spectral efficiency, and advanced digital signal processing using state-of-the-art electronics are the main features for next generation optical networks. These technologies are complementary integrated together to develop optical superchannel transmission. This paper demonstrates an optical comb source with variable number of subcarriers and apply reconfigurable modulation and transmission reaching DP-16QAM/23Gbaud/23subcarriers, i.e. data rate of 4.2Tbps over 4.6nm spectral region and spectral efficiency of 7.36 b/s/Hz.