Jiangwei Man

Experimental study of PAM-4, CAP-16, and DMT for 100 Gb/s short reach optical transmission systems.

Advanced modulation formats combined with digital signal processing and direct detection is a promising way to realize high capacity, low cost and power efficient short reach optical transmission system. In this paper, we present a detailed investigation on the performance of three advanced modulation formats for 100 Gb/s short reach transmission system. They are PAM-4, CAP-16 and DMT. The detailed digital signal processing required for each modulation format is presented. Comprehensive simulations are carried out to evaluate the performance of each modulation format in terms of received optical power, transmitter bandwidth, relative intensity noise and thermal noise. The performance of each modulation format is also experimentally studied. To the best of our knowledge, we report the first demonstration of a 112 Gb/s transmission over 10km of SSMF employing single band CAP-16 with EML. Finally, a comparison of computational complexity of DSP for the three formats is presented.

140-Gb/s 20-km Transmission of PAM-4 Signal at 1.3

We experimentally demonstrated 140-Gb/s transmission over 20-km standard single-mode fiber employing pulse-amplitude modulation (PAM)-4 and direct detection (DD) at 1.3 μm. DD faster than Nyquist is employed to compensate for channel impairments. The optimal length of taps of decision directed least mean square and the optimal tap coefficient for digital postfilter are investigated. A receiver sensitivity of -5.5 dBm at bit error rate of 3.8× 10-3 is realized for 140-Gb/s PAM-4 signal after 20-km transmission. To the best of our knowledge, this is the highest reported baud rate (70 GBd) of direct detected PAM-4 signal and the highest per channel bit rate with single polarization and DD for short reach communications.

\mu \text{m}

We proposed a novel 100Gb/s PON scheme using 4-PAM modulation with commercial low-cost 10Gbps TOSA/ROSA compatible with 40Gb/s TWDM-PON. Experimental results show that with EQ compensating bandwidth limitation and CD, 30km transmission is available.

for Short Reach Communications

With the introduction of PAM4 modulation, a novel 100GE optical transceiver module has been proposed using the low-cost 4×10Gbps DML TOSA and PIN ROSA. 4×25Gbps PAM4 signal transmission has been demonstrated over 2km SMF on-line with -11dBm sensitivity and 4dB link margin.

30km Downstream Transmission Using 4×25Gb/s 4-PAM Modulation with Commercial 10Gbps TOSA and ROSA for 100Gb/s-PON

We present a wavelength locking platform enabling the feedback control of silicon (Si) microring resonators (MRRs) for the realization of a 4 × 10 Gb/s wavelength-division-multiplexing (WDM) transmitter. Four thermally tunable Si MRRs are employed to multiplex the signals generated by four directly modulated lasers (DMLs) operating in the L-band, as well as to improve the quality of the DMLs signals. Feedback control is achieved through a field-programmable gate array controller by monitoring the working point of each MRR through a transparent detector integrated inside the resonator. The feedback system provides an MRR wavelength stability of about 4 pm (0.5 GHz) with a time response of 60 ms. Bit error rate (BER) measurements confirm the effectiveness and the robustness of the locking system to counteract sensitivity degradations due to thermal drifts, even under uncooled operation conditions for the Si chip.

A Low-Cost 100GE Optical Transceiver Module for 2km SMF Interconnect with PAM4 Modulation

A 112Gbit/s single polarization half-cycle 16QAM Nyquist-subcarrier-modulation signal was generated and transmitted over 10km of SMF employing 25Gbps EML and direct detection for short reach communications. This is the highest reported bit rate of direct detected half-cycle 16QAM Nyquist-SCM signal on single wavelength and single polarization.

Wavelength Locking of Silicon Photonics Multiplexer for DML-Based WDM Transmitter

Utilizing the advantages of less bandwidth requirement and chromatic dispersion penalty, PAM4 modulation has been discussed for Ethernet optical transceiver as well as passive optical network, including the low-cost 100GE 2km, 400GE 2km/10km/40km solutions and high-speed 25Gbps/40Gbps PON. Meanwhile, the system performance has also been evaluated experimentally.

Transmission of 112Gbit/s single polarization half-cycle 16QAM Nyquist-SCM with 25Gbps EML and direct detection

A low-cost 4×25Gbps PAM4 module for short-reach optical interconnection has been proposed using the commercial low-cost 10Gbps DML TOSA and PIN ROSA. This scheme has been demonstrated over 2km SMF and can also be used for MMF interconnection.

High speed optical interconnects with PAM4 modulation for short-reach applications

PAM4 is a promising solution for the high speed optical interconnection, it aligns well with the trend of modulation technologies and allows using lower cost optical components. This paper summarizes the experimental demonstration of PAM4 under different speed for the next generation 100GE, 400GE and beyond with the introduction of PAM4, lessons learned from industry standards and the perspective on the tendency will be presented.

A low-cost 4×25Gbps PAM4 module for short-reach optical interconnection

We propose downstream transmission of 25-Gb/s and 40-Gb/s Faster-than-Nyquist signals based on NRZ and PAM4 for high-capacity PON using low-cost 10G optics, respectively achieving -23.9 dBm and -20 dBm receiver sensitivities after 20-km SSMF.