Research

Research Projects:

1. UltraFlow: A Hybrid Future Internet Architecture

• In recent years, the Internet has been challenged by increasing data rate. With IP-based (layer 3) routing, Electrical Packet Switching (EPS) is an efficient solution for relatively low-speed data transmission (≤100Mbps). However, emerging bandwidth-intensive applications such as HD video streaming, large file transfer and high-speed data transmission (≥1Gbps) is a stringent burden for IP routing overhead. Consequently, Optical Flow Switching (OFS) has been proposed as a cost-effective solution in which Flow connections, with dedicated lightpaths, bypass IP routers to enable efficient end-to-end optical communication. We have demonstrated a novel 10 Gbps per-wavelength UltraFlow optical access network architecture, which cooperates with legacy PONs to offer dual-mode, IP and Flow, data transmission. Testbed experiments show that all OFNU configurations can achieve bidirectional error-free transmission with no impact on IP transmission. Theoretical calculations also show that the number of users in the proposed architecture can exceed 64 for a 20 km transmission distance.

References:

1. Shuang Yin, Thomas Shunrong Shen, Yingying Bi, Jing Jin, Tomofumi Oyama, and Leonid G. Kazovsky, “A Novel Quasi-Passive, Software-Defined, and Energy Efficient Optical Access Network for Adaptive Intra-PON Flow Transmission” in IEEE/OSA Journal of Lightwave Technology (JLT), vol. 33, issue 22, pp. 4536-4546, November 2015.
2. Shuang Yin, Thomas Shunrong Shen, Yingying Bi, Jing Jin, and Leonid G. Kazovsky, “Remotely Pumped and High Splitting Ratio (1:512) Intra-PON Flow Transmission via a Distantly Powered Quasi-Passive Reconfigurable (QPAR) Node” in European Conference on Optical Communication (ECOC) 2015, paper Tu.1.5.6, Valencia, Spain, September 2015.
3. Thomas Shunrong Shen, Shuang Yin, and Leonid G. Kazovsky, “IP Resource Sharing Framework in Dual-Mode UltraFlow Access Network” in IEEE/OSA Journal of Optical Communications and Networking (JOCN), vol. 7, issue 5, pp. 401-411, May 2015.
4. Thomas Shunrong Shen, Shuang Yin, Ahmad R. Dhaini, and Leonid G. Kazovsky, “Reconfigurable Long-Reach UltraFlow Access Network: A Flexible, Cost-Effective and Energy-Efficient Solution” in IEEE/OSA Journal of Lightwave Technology (JLT), vol. 32, issue 13, pp. 2353-2363, July 2014.
5. Shuang Yin, Ahmad R. Dhaini, Thomas Shunrong Shen, Ben Detwiler, Marc De Leenheer, Talip Ucar, and Leonid G. Kazovsky, “UltraFlow Access Testbed: Experimental Exploration of Dual-Mode Access Networks” in IEEE/OSA Journal of Optical Communications and Networking (JOCN), vol. 5, issue 12, pp. 1361-1372, December 2013. (Featured as top downloaded articles in November 2013 from OSA’s Journal of Optical Communications Networking (JOCN), News)
6. Leonid G. Kazovsky, Ahmad R. Dhaini, Marc De Leenheer, Thomas Shunrong Shen, Shuang Yin and Ben Detwiler, “UltraFlow Access Networks: a Dual-Mode Solution for the Access Bottleneck” in International Conference on Transparent Optical Networks (ICTON) 2013, paper Tu.C3.1, Cartagena, Spain, June 2013.

2. High speed (≥ 25 Gbps per λ) TDM-PON with Low-cost Components

• Until now, all generations of commercially deployed passive optical networks (PONs) have been bi-directional, power-splitter-based low-cost time division multiplexed-time division multiple access (TDM-TDMA) systems. However, challenges associated with increasing the serial bit-rate, including meeting the optical power budget, the decreased dispersion tolerance and the increased cost of implementation questions the feasibility of TDM for higher bit-rate PON. For this reason, FSAN (Full Service Access Network) abandoned the single-wavelength evolutionary path in favor of TWDM-PON. Still, the development of practical low-cost single-wavelength solutions at 25 and 40 Gbps are of great interest and are therefore being studied in the NG-EPON ad-hoc initiative that recently began in IEEE 802.3. 25 Gbps TDM-PON is technically feasible with high volume 10G optical parts when 3-level duobinary detection and PAM-4 modulation schemes are applied. For 40 Gbps case, DSP, i.e., pre- and post-equalization (FFE and DFE), is needed to maintain low-cost with 10G optical parts. Optical amplification (EDFA) are considered in both cases to maximize the power budget. Its transient effect with burst-mode traffic needs careful management.

References:

1. Shuang Yin, Vincent Houtsma, Dora van Veen, and Peter Vetter, "Optical Amplified 40-Gbps Symmetrical TDM-PON using 10-Gbps Optics and DSP" in IEEE/OSA Journal of Lightwave Technology (JLT), 2017. (Invited)
2. Shuang Yin, Dora van Veen, Vincent Houtsma, and Peter Vetter, “Investigation of Symmetrical Optical Amplified 40 Gbps PAM-4/Duobinary TDM-PON using 10G Optics and DSP” in Optical Communication Conference (OFC) 2016, Paper Tu3C.2, Anaheim, CA, March 2016. (Featured as Top-Scored Paper in OFC 2016)
3. Vincent Houtsma, and Dora van Veen, “Demonstration of symmetrical 25 Gbps TDM-PON with 31.5 dB optical power budget using only 10 Gbps optical components” in European Conference on Optical Communication (ECOC) 2015, paper PDP.4.3, Valencia, Spain, September 2015.
4. Vincent Houtsma, Dora van Veen, Alan Gnauck, and Patrick Iannone, “APD-based duobinary direct detection receivers for 40 Gbps TDM-PON” in Optical Communication Conference (OFC) 2015, Paper Th4H.1, Los Angeles, CA, March 2015.
5. Dora van Veen, Vincent Houtsma, Alan Gnauck, and Patrick Iannone, “40-Gb/s TDM-PON over 42 km with 64-way power split using a binary direct detection receiver” in European Conference on Optical Communication (ECOC) 2014, paper PD.1.4, Cannes, France, September 2014.

3. 56 Gb/s PAM-4 per λ via 10 Gbps InP MZM for Intra-Data Center Interconnect (100 km)

• Advanced modulation formats, e.g., discrete multi-tone (DMT) and PAM-4, have gained increasing interest lately to provide better performance in terms of cost, power consumption and spectral efficiency. Especially, PAM-4 can achieve twice the spectral efficiency comparing to conventional NRZ case, and still maintain low cost and power consumption with light-weighted DSP. We propose to use PAM-4 and a legacy 10 Gb/s Indium-phosphide (InP) Mach-Zehnder modulator (MZM), co-packaged with a tunable Laser (TLMZ), to carry 56 Gb/s data per wavelength in a fully-compensated, 100 km DWDM system for inter-data center connections. The implication of being able to use a 10 Gb/s InP TLMZ is the feasibility of a low-cost and compact pluggable transceiver solution.

References:

1. Shuang Yin, Trevor Chan, and Winston I. Way, “100-km DWDM Transmission of 56-Gb/s PAM4 per λ via Tunable Laser and 10-Gb/s InP MZM” in IEEE Photonics Technology Letters (PTL), vol. 27, issue 24, pp. 2531-2534, December 2015.

4. 10/50/100/400 Gb/s Discrete Multi-Tone (DMT) based Optical Communication System

• Discrete multi-tone (DMT) and Orthogonal frequency-division multiplexing (OFDM) have been envisioned as a prominent modulation/multiplexing technique for optical communication in access, client and line side of the current network. Thanks to the well-developed DSP technology, DMT and OFDM can take advantage of higher order quadrature amplitude modulation (QAM) format to effectively achieves high spectral efficiency and ultimately lowers the bandwidth requirement of components. In addition, it is easier to use DSP to compensate detrimental channel impairments, e.g. dispersion, nonlinearity, etc., in the frequency domain. With proper power and bit loading, DMT and OFDM can potentially be used to build a transceiver with flexible modulation formats controlled by software, hence software defined optics (SDO).

References:

1. Trevor Chan, I-Cheng Lu, Jyehong Chen, and Winston I. Way, “400-Gb/s Transmission Over 10-km SSMF Using Discrete Multitone and 1.3-μm EMLs” in IEEE Photonics Technology Letters, vol. 26, no. 16, pp. 1657–1660, August 2014.

5. 10 Gb/s Optical Burst Mode Clock and Data Recovery (BM CDR) Circuit

• The rapid growing of the last mile solution such as passive optical networks (PONs) activates research on burst mode data operation where the optical line terminal (OLT) must deal with asynchronous packets with different amplitude and phase, necessitating clock and data recovery (CDR) circuit with fast clock recovery and data retiming. In future optical packet switching (OPS) network, burst mode operation is essential to conduct burst packet aggregation at the OPS edge router. In both cases, a burst-mode receiver (BMRx) plays a key role which is responsible for amplitude and phase recovery at the beginning of every packet. We have demonstrated a novel BM-CDR technique based on phase picking method by mixing the extracted data clock with four phase-delayed copies of the local clock at the same rate as the data. Two important characteristics of the BM-CDR are its phase acquisition time and accuracy of the phase alignment. Here, a phase synchronization time of 20 ns and phase alignment accuracy of ±π/8 are achieved which are sufficient for 10 gigabit Ethernet PON (10G-EPON) application according to IEEE802.3 av 10G-EPON standards and may be also useful for future optical packet switching network.

References:

1. Runxiang Yu, Roberto Proietti, Shuang Yin, and S. J. B. Yoo, “A 10-Gbps Burst-Mode Clock and Data Recovery Circuit with Synchronous Data Output for Optical Networks” in IEEE Photonics Technology Letters, vol. 25, issue. 5, pp. 508-511, March 2013.
2. Runxiang Yu, Roberto Proietti, Shuang Yin, Junya Kurumida, and S. J. B. Yoo, “A 10Gbps Burst-Mode Clock and Data Recovery Circuit with Continuous Clock Output” in Photonics in Switching Conference, Paper Th-S25-O12, September 2012.
3. Shuang Yin, “10Gb/s Burst Mode Clock and Data Recovery in Optical Label Switching (OLS) System”, UC Davis & Zhejiang University, June 2011.

6. Fast Switching Current Laser Driver in Optical Label Switching (OLS) System

All-optical wavelength converter (WC) is one of the key components in future optical packet switching (OPS) system. In such optical switching systems, fast tuning WC (especially tunable laser) is extremely important for reducing the packet guard time and achieving low latency switching. We have demonstrated a fast switching current laser driver which can reduce AWG router switching time from 30ns to less than 10ns. In addition, good DC current stability of the driver is verified via laser calibration result with multi-wavelength-meter.

References:

1. Shuang Yin, “Fast Switching Current Laser Driver in Optical Label Switching (OLS) Systems” in GREAT Program Symposium, UC Davis, September 2010.

7. 2.5 Gb/s Radio over Fiber (RoF) system

Radio over Fiber (RoF) technology entails the use of optical fiber links to distribute RF signals from a central station (CS) to Remote Antenna Units (RAUs) or base stations (BSs). RoF makes it possible to centralize the RF signal processing functions in one shared location and then to use optical fiber, which offers low signal loss. What’s more, RAUs are simplified significantly, as they only need to perform optoelectronic conversion and amplification functions.The centralization of RF signal processing functions enables equipment sharing, dynamic allocation of resources, and simplified system operation and maintenance. We have designed and demonstrated a specific RoF architecture. By setting an extra Laser in CS, we are able to reduce the Laser needed in each BS. In addition, electro-absorption modulator (EAM) has been used as a modulator and photodetector to realize full duplex transmission. System measurement, i.e. BER, eye diagram, has been done to prove its feasibility.