Approved for public release; distribution is unlimited / Future underwater missions will require data transmission via satellite. In particular, the Office of Naval Research (ONR) is interested in experimenting with communications using the GOES satellite system, which is government owned. Unfortunately, communication antennas must point to specific satellites in this system and thus underwater vehicles must steer a specific course on the surface during the communication process. While surfaced, underwater vehicles are subject to wind and wave disturbances and it has been suggested that control using differential thrust from propellers may provide advantages. This thesis covers efforts to create and test such a steering autopilot based on the use of the ARIES AUV and differing the voltage supplied to each propeller. It is planned to use the ARIES in an ocean experiment to test this satellite communication capability. This control is embedded in the control of ARIES during extended pop up maneuvers for GPS navigational fixes. When surfaced, not only are navigational fixes obtained, but also data packets are communicated to a command center. / Lieutenant, United States Navy

by Ngai Tin Yee. / Bibliography: leaves [28]-[29] / Thesis (M.Ph.)--Chinese University of Hong Kong, 1984

Chui Sai Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 73-77). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Wireless LAN --- p.3 / Chapter 1.2.1 --- Ad Hoc Mode --- p.3 / Chapter 1.2.2 --- Infrastructure Mode --- p.3 / Chapter 1.3 --- Handoff --- p.4 / Chapter 1.3.1 --- IP Layer Handoff --- p.5 / Chapter 1.3.2 --- MAC Layer Handoff --- p.6 / Chapter 1.4 --- Voice over Internet Protocol (VoIP) --- p.6 / Chapter 1.5 --- Significance of Research Outcomes --- p.8 / Chapter 1.6 --- Outline of Thesis --- p.10 / Chapter 2 --- Background Study --- p.11 / Chapter 2.1 --- Handoff Process --- p.12 / Chapter 2.2 --- MAC Layer Handoff --- p.12 / Chapter 2.2.1 --- MAC Layer Handoff Process --- p.12 / Chapter 2.2.2 --- MAC Layer Handoff Scheme --- p.16 / Chapter 2.3 --- IP Layer Handoff --- p.20 / Chapter 2.3.1 --- IP Layer Handoff Process --- p.20 / Chapter 2.3.2 --- IP Layer Handoff Scheme --- p.22 / Chapter 2.4 --- Chapter Summary --- p.25 / Chapter 3 --- AP Coordination System and Performance Analysis for Sync-Scan --- p.26 / Chapter 3.1 --- Introduction --- p.26 / Chapter 3.2 --- Problem Formulation --- p.27 / Chapter 3.3 --- Fast Handoff Scheme --- p.27 / Chapter 3.3.1 --- Access Point Coordination System --- p.28 / Chapter 3.3.2 --- Simulation Results --- p.30 / Chapter 3.3.3 --- Further Discussion --- p.33 / Chapter 3.3.4 --- Improved Handoff Process --- p.34 / Chapter 3.4 --- SyncScan Performance Analysis --- p.36 / Chapter 3.4.1 --- Beacon Delay --- p.36 / Chapter 3.4.2 --- Handoff Latency --- p.38 / Chapter 3.5 --- Chapter Summary --- p.41 / Chapter 4 --- Handoff Control Message Analysis --- p.43 / Chapter 4.1 --- Introduction --- p.43 / Chapter 4.2 --- Problem Formulation --- p.44 / Chapter 4.3 --- Key System Parameters --- p.45 / Chapter 4.4 --- System Model --- p.47 / Chapter 4.4.1 --- Markov Modulated Poisson Process (MMPP) Model --- p.47 / Chapter 4.4.2 --- System Time Distribution --- p.52 / Chapter 4.5 --- Performance Analysis --- p.58 / Chapter 4.6 --- Further Discussion --- p.63 / Chapter 4.6.1 --- Handoff Scheme Strategy --- p.63 / Chapter 4.6.2 --- Channel Reservation for Handoff Process --- p.66 / Chapter 4.7 --- Chapter Summary --- p.68 / Chapter 5 --- Conclusion --- p.70 / Bibliography --- p.73

Yang Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 51-55). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.II / ABSTRACT --- p.III / 摘要 --- p.IV / CONTENTS --- p.V / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter 1.1. --- Modulation Formats in Optical Communication SYSTEMS --- p.2 / Chapter 1.1.1 --- Optical ASK Format --- p.3 / Chapter 1.1.2 --- Optical FSK Format --- p.4 / Chapter 1.1.3 --- Optical PSK Format --- p.5 / Chapter 1.1.4 --- Optical Orthogonal Modulation --- p.7 / Chapter 1.2. --- All-Optical Packet Switching --- p.8 / Chapter 1.2.1 --- AOLS Using Subcarrier Labels --- p.9 / Chapter 1.2.2 --- Serial Labels --- p.10 / Chapter 1.2.3 --- Orthogonal Modulated Labels --- p.12 / Chapter 1.3. --- Optical Supervisory Control --- p.13 / Chapter 1.3.1 --- OXC Supervisory Schemes --- p.13 / Chapter 1.3.2 --- Optical A mplifier Supervisory Schemes --- p.14 / Chapter 1.3.3 --- Optical Supervisory Schemes for Transmission Networks --- p.15 / Chapter 1.4. --- Thesis Organization --- p.16 / Chapter CHAPTER 2: --- PREVIOUS STUDIES ON OPTICAL ORTHOGONAL MODULATION….… --- p.17 / Chapter 2.1. --- Orthogonal Modulation Used in STARNET --- p.17 / Chapter 2.2. --- AOLS in IP-over-WDM Networks Employing Orthogonal Modulation --- p.18 / Chapter 2.2.1 --- DPSK Labels on ASK Payload --- p.18 / Chapter 2.2.2 --- FSK Labels on ASK Payload --- p.20 / Chapter 2.2.3 --- Experimental Result of ASK/DPSK Label Swapping --- p.21 / Chapter 2.3. --- Quaternary Optical ASK-DPSK Modulation --- p.22 / Chapter 2.4. --- Conclusion --- p.23 / Chapter CHAPTER 3: --- OPTICAL DPSK/ASK ORTHOGONAL MODULATION SCHEME --- p.24 / Chapter 3.1. --- motivation --- p.24 / Chapter 3.2. --- Proposed Optical DPSK/ASK Orthogonal Modulation Scheme --- p.25 / Chapter 3.3. --- DPSK/ASK orthogonal modulation modules --- p.26 / Chapter 3.4. --- Numerical Simulations --- p.27 / Chapter 3.4.1 --- Mathematical Model of DPSK/ASK Signal --- p.28 / Chapter 3.4.2 --- Simulation Model --- p.31 / Chapter 3.4.3 --- Simulation Results --- p.32 / Chapter 3.5. --- Experimental Demonstration --- p.34 / Chapter 3.5.1 --- Experimental Setup --- p.34 / Chapter 3.5.2 --- Experimental Results --- p.36 / Chapter 3.6. --- transmission experiment --- p.38 / Chapter 3.7. --- Supervisory Information Dissemination Using DPSK/ASK Orthogonal Modulation --- p.41 / Chapter 3.8. --- Label Swapping Experiment and Results --- p.42 / Chapter 3.8.1 --- Experiment Setup --- p.42 / Chapter 3.8.2 --- Experiment Results --- p.45 / Chapter CHAPTER 4: --- CONCLUSION --- p.48 / Chapter 4.1. --- Thesis Summary --- p.48 / Chapter 4.2. --- Future Work --- p.49 / LIST OF PUBLICATIONS --- p.50 / REFERENCES --- p.51

Deng Yun. / Thesis submitted in: July 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 54-56). / Abstracts in English and Chinese. / Acknowledgments --- p.ii / 摘要 --- p.iii / Abstract --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Optical Switching --- p.1 / Chapter 1.1.1 --- Optical Circuit Switching --- p.2 / Chapter 1.1.2 --- Optical Packet Switching --- p.3 / Chapter 1.1.3 --- Optical Burst Switching --- p.4 / Chapter 1.2 --- Design of Optical Burst Switching Node --- p.8 / Chapter 1.2.1 --- Burst Switched Network Architecture --- p.8 / Chapter 1.2.2 --- Design of Optical Burst Switching Node --- p.10 / Chapter 1.2.3 --- Scalable Architecture With Multi-plane Fabric --- p.12 / Chapter 1.3 --- Organization --- p.13 / Chapter Chapter 2 --- Proposed OBS Node and Blocking probability due to Output Contention --- p.14 / Chapter 2.1 --- OBS Node Architecture --- p.14 / Chapter 2.2 --- Burst Traffic Model --- p.16 / Chapter 2.3 --- Blocking Probability due to Output Contention --- p.17 / Chapter 2.4 --- Poisson Approximation of Burst Traffic --- p.19 / Chapter 2.5 --- Simulation Results --- p.21 / Chapter Chapter 3 --- Deflection Routed Switch Based on Shuffle-exchange network and Burst Loss Rate due to Insufficient Number of Stages --- p.22 / Chapter 3.1 --- Architecture of Shuffle-exchange Network --- p.22 / Chapter 3.2 --- The traffic loading entering into the second stage --- p.23 / Chapter 3.3 --- The Deflection Probability in a 2x2 Switching Module of SN --- p.26 / Chapter 3.4 --- Analysis of Burst Loss Rate due to Insufficient Number of Stages in SN --- p.27 / Chapter 3.5 --- Total Burst Loss Probability --- p.30 / Chapter 3.6 --- Multi-plane Architecture --- p.32 / Chapter 3.6.1 --- Relationship between k and loading of SN --- p.33 / Chapter 3.6.2 --- Relationship between k and n: Log2(Number of input-output ports) --- p.36 / Chapter 3.6.3 --- The result of appropriate number of planes k --- p.38 / Chapter Chapter 4 --- Switch Based on Dual Shuffle-exchange network and Comparison with Shuffle-exchange network --- p.40 / Chapter 4.1 --- Architecture of Dual Shuffle-exchange Network --- p.40 / Chapter 4.2 --- The deflection Probability in a 4x4 Switching Module of DSN --- p.41 / Chapter 4.3 --- Burst Loss Rate due to Insufficient Number of Stages of DSN --- p.43 / Chapter 4.4 --- Comparison of SN and DSN --- p.45 / Chapter 4.4.1 --- Comparison with different n --- p.47 / Chapter 4.4.2 --- Comparison with different loading --- p.48 / Chapter 4.4.3 --- The result of comparison --- p.49 / Chapter Chapter 5 --- Conclusions --- p.50 / Chapter 5.1 --- The Burst Loss Probability of Proposed OBS Based on SN --- p.51 / Chapter 5.2 --- The multi-plane Fabric with appropriate number of planes k --- p.51 / Chapter 5.3 --- Performance of OBS Design Based on DSN and Comparison of SN and DSN --- p.52 / Bibliography --- p.54

Wong Kar Yiu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 109-111). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgement --- p.iv / Table of Contents --- p.v / List of Figure --- p.vii / Chapter Chapter 1. --- Introduction --- p.9 / Chapter 1.1 --- Introduction --- p.9 / Chapter 1.2 --- Background --- p.11 / Chapter 1.3 --- Ant Colony Optimization (ACO) --- p.15 / Chapter 1.4 --- Main contribution --- p.16 / Chapter 1.5 --- Thesis organization --- p.18 / Chapter Chapter 2. --- Related Work --- p.19 / Chapter 2.1 --- Multicast routing in general --- p.19 / Chapter 2.2 --- Multicast routing techniques --- p.22 / Chapter 2.3 --- Best-effort multicast routing --- p.25 / Chapter 2.4 --- Quality-of-Service (QoS) multicast routing --- p.30 / Chapter 2.5 --- Adaptive multicast routing --- p.34 / Chapter Chapter 3. --- Load-Sensitive Multicast Routing Protocol (LSMRP) --- p.37 / Chapter 3.1 --- Overview --- p.37 / Chapter 3.2 --- Problem Formulation --- p.37 / Chapter 3.3 --- Types of ant in LSMRP --- p.39 / Chapter 3.3.1 --- Forward Ants --- p.39 / Chapter 3.3.2 --- Random Ants --- p.41 / Chapter 3.3.3 --- Backward Ants --- p.42 / Chapter 3.3.4 --- Multicast Ants --- p.44 / Chapter 3.3.5 --- Multicast Backward Ants --- p.44 / Chapter 3.4 --- Global Algorithm --- p.47 / Chapter 3.4.1 --- Pheromone trails stage --- p.50 / Chapter 3.4.2 --- Multicast tree stage --- p.53 / Chapter 3.4.3 --- Routing table --- p.56 / Chapter 3.4.4 --- Messages Exchange and Mechanisms --- p.57 / Chapter 3.4.5 --- mapping --- p.58 / Chapter 3.4.6 --- Members join --- p.59 / Chapter 3.4.7 --- Members update --- p.59 / Chapter 3.4.8 --- Members leave --- p.61 / Chapter Chapter 4. --- Analysis of LSMRP --- p.63 / Chapter 4.1 --- Analysis of pheromone trail values --- p.63 / Chapter Chapter 5. --- Evaluation and Experimental Results --- p.80 / Chapter 5.1 --- System model --- p.80 / Chapter 5.2 --- Result --- p.84 / Chapter 5.2.1 --- Packets received --- p.84 / Chapter 5.2.2 --- Throughput --- p.86 / Chapter 5.2.3 --- Packet Loss --- p.98 / Chapter Chapter 6. --- Conclusion --- p.107 / Chapter 6.1 --- Future work/ open question --- p.107 / References --- p.109

Deng Ning. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 62-65). / Abstracts in English and Chinese. / ABSTRACT --- p.iii / 摘要 --- p.v / Chapter 1 --- BACKGROUND AND INTRODUCTION --- p.1 / Chapter 1.1 --- Optical Frequency-Shift Keying (FSK) --- p.1 / Chapter 1.1.1 --- Basic concepts and research hotspots of optical FSK --- p.1 / Chapter 1.1.2 --- Optical FSK Transmitter and Receiver --- p.3 / Chapter 1.2 --- Wavelength Division Multiplexing Optical Passive Networks --- p.8 / Chapter 1.3 --- Optical Label Switching (OLS) Networks --- p.10 / Chapter 1.4 --- Thesis Contribution and Organization --- p.11 / Chapter 2 --- DATA RE-MODULATION ON DOWNSTREAM OPTICAL FSK SIGNALS IN WDM-PONS --- p.12 / Chapter 2.1 --- overview of related works --- p.12 / Chapter 2.2 --- PON ARCHITIiCTURE USING DOWNSTREAM OPTICAL FSK SIGNALS --- p.13 / Chapter 2.3 --- CLS PON DEMONSTRATION USING THREE DIFFERENT OPTICAL FSK TRANSMITTERS --- p.14 / Chapter 2.3.1 --- With an optical FSK transmitter based on direct modulation in a DFB laser --- p.14 / Chapter 2.3.2 --- With an optical FSK transmitter based on complementary intensity modulation --- p.17 / Chapter 2.3.3 --- With our proposed optical FSK transmitter based on phase modulation --- p.21 / Chapter 2.4 --- System Performance by Using Phase Modulation Based FSK Transmitter…… --- p.26 / Chapter 2.4.1 --- Wavelength detune of light sources --- p.27 / Chapter 2.4.2 --- Detune of the DI frequency response --- p.29 / Chapter 2.4.3 --- Dispersion tolerance --- p.30 / Chapter 2.5 --- Summary --- p.32 / Chapter 3 --- INTENSITY-MODULATED LABELLING ON OPTICAL FSK OR DPSK PAYLOADS IN OLS NETWORKS --- p.34 / Chapter 3.1 --- Existing Labelling Schemes and Their Features --- p.34 / Chapter 3.1.1 --- Bit serial labelling --- p.35 / Chapter 3.1.2 --- Subcarrier multiplexed (SCM) labelling --- p.36 / Chapter 3.1.3 --- Orthogonally modulated labelling --- p.37 / Chapter 3.2 --- The Proposed 00K Labelling Scheme and OLS System Architecture --- p.38 / Chapter 3.3 --- All-Optical Label Swapping and Other Critical Issues --- p.39 / Chapter 3.4 --- System demonstration --- p.40 / Chapter 3.5 --- Summary --- p.45 / Chapter 4 --- PERFORMANCE CHARACTERIZATION OF THE ASK/FSK AND ASK/DPSK ORTHOGONAL SIGNALS --- p.46 / Chapter 4.1 --- Introduction and Formulation --- p.46 / Chapter 4.2 --- Theoretical Analysis --- p.48 / Chapter 4.2.1 --- Optical ASK performance in orthogonal signals --- p.48 / Chapter 4.2.2 --- Optical FSK performance in ASK/FSK signals --- p.49 / Chapter 4.2.3 --- Optical DPSK performance in ASK/DPSK signals --- p.51 / Chapter 4.3 --- Analytical and Experimental Results --- p.55 / Chapter 4.4 --- Conclusion --- p.57 / Chapter 5 --- SUMMARY --- p.58 / Chapter 5.1 --- Thesis Summary --- p.58 / Chapter 5.2 --- Future Work --- p.59 / LIST OF PUBLICATIONS --- p.61 / REFERENCES --- p.62

by Yee Ka Chi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 101-[106]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.1.1 --- Large Scale Switch Interconnections --- p.2 / Chapter 1.1.2 --- Multichannel Switching and Resequencing --- p.6 / Chapter 1.1.3 --- Scheduling --- p.7 / Chapter 2 --- Hierarchical Banyan Switch Interconnection --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Switch Architecture --- p.13 / Chapter 2.3 --- Switch Operation --- p.19 / Chapter 2.3.1 --- Call Setup --- p.19 / Chapter 2.3.2 --- Cell Routing --- p.21 / Chapter 2.3.3 --- Fault Tolerance --- p.27 / Chapter 2.4 --- Call Blocking Analysis --- p.28 / Chapter 2.4.1 --- Dilated Banyan --- p.29 / Chapter 2.4.2 --- Dilated Benes Network --- p.30 / Chapter 2.4.3 --- HBSI --- p.30 / Chapter 2.5 --- Results and Discussions --- p.31 / Chapter 2.6 --- Summary --- p.37 / Chapter 3 --- Multichannel Switching and Resequencing --- p.40 / Chapter 3.1 --- Introduction --- p.40 / Chapter 3.2 --- Channel Assignment --- p.41 / Chapter 3.2.1 --- VC-Based Channel Allocation Mechanism --- p.41 / Chapter 3.2.2 --- Port-Based Channel Allocation Mechanism --- p.45 / Chapter 3.2.3 --- Trunk-Based Channel Allocation Mechanism --- p.46 / Chapter 3.3 --- Resequencer --- p.50 / Chapter 3.3.1 --- Resequencing Algorithm --- p.50 / Chapter 3.4 --- Results and Discussion --- p.55 / Chapter 3.5 --- Summary --- p.60 / Chapter 4 --- Scheduling --- p.62 / Chapter 4.1 --- Introduction --- p.62 / Chapter 4.2 --- Virtual Clock Scheduling (VCS) --- p.62 / Chapter 4.3 --- Gated Virtual Clock Scheduling (GVCS) --- p.70 / Chapter 4.4 --- Time-Priority Model --- p.75 / Chapter 4.5 --- Programmable Rate-based Scheduler (PRS) --- p.80 / Chapter 4.6 --- Integration with Resequencer --- p.83 / Chapter 4.7 --- Results and Discussions --- p.86 / Chapter 4.8 --- Summary --- p.96 / Chapter 5 --- Conclusion --- p.99 / Bibliography --- p.101

by Gao Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 62-[65]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Purpose of Study --- p.5 / Chapter 1.3 --- Organization of Chapters --- p.7 / Chapter 2 --- Overview of Optical Burst-Mode Receivers --- p.8 / Chapter 2.1 --- Introduction --- p.8 / Chapter 2.2 --- Burst-Mode Data Transmission --- p.9 / Chapter 2.3 --- Two Main Issues on Burst-Mode Receiver --- p.11 / Chapter 2.4 --- Model of Burst-Mode Receiver --- p.13 / Chapter 2.5 --- Threshold Detection in Burst-Mode Receiver --- p.16 / Chapter 2.6 --- Sensitivity Penalty in Burst-Mode Receiver --- p.20 / Chapter 2.7 --- Chapter Summary --- p.22 / Chapter 3 --- Optimal Detection Threshold in Burst-mode Receiver --- p.24 / Chapter 3.1 --- Introduction --- p.24 / Chapter 3.2 --- Threshold Fluctuation in Burst-Mode Receiver --- p.25 / Chapter 3.3 --- BER of Burst-Mode Receiver --- p.27 / Chapter 3.4 --- Optimal Detection Threshold of Burst-Mode Receivers --- p.31 / Chapter 3.5 --- Simulation Result on the BER of Burst-mode Receiver --- p.36 / Chapter 3.6 --- Chapter Summary --- p.38 / Chapter 4 --- MLT-3 Burst-Mode Receiver --- p.41 / Chapter 4.1 --- Introduction --- p.41 / Chapter 4.2 --- MLT-3 Line Code --- p.42 / Chapter 4.3 --- BER Performance of MLT-3 Continuous-Mode Receiver --- p.45 / Chapter 4.4 --- Burst-mode Receiver For MLT-3 Line Code --- p.49 / Chapter 4.5 --- BER Performance of MLT-3 Burst-Mode Receiver --- p.52 / Chapter 4.6 --- Chapter Summary --- p.55 / Chapter 5 --- Conclusion --- p.59 / Bibliography --- p.62

Data communication is a critical component of modern technology in our society. There is an increasing reliance on information being at our fingers tips and we expect a low-latency, high-bandwidth connection to deliver entertainment or enhanced productivity. In order to serve this demand, communications devices are being pressed for smaller form factors, higher data throughput, lower power consumption and lower cost. Similar demands exist in a number of applications including metro/long-haul telecommunications, shorter datacenter links and supercomputing. Silicon photonics promises to be a technology that will solve some of the difficulties with improving communication devices. Building photonics in silicon allows for reuse of the same fabrication technology that is used by the CMOS electronics industry, potentially allowing for large volumes, high yields and low costs. Part I of this thesis details the design of components needed in a high-speed silicon photonic platform to meet the current challenges for high-speed communications. The author’s work in modeling photodetectors resulted in improving photodetector bandwidth from 30 GHz to 67 GHz, the fastest reported at the time of publication. Details regarding the optimization and test of modulators are also presented with the first-reported 50 Gbps modulator at 1310-nm. A large scale parallel channel demonstration of high-speed silicon photonics is then presented showing the potential scalability for silicon photonics systems. A full transceiver requires a number of components other than the photodetector and modulator that are the core active pieces of a silicon photonics platform. Part II includes work on the design and test of silicon photonic components providing functionality beyond the photodetector and modulator. A novel design integrating Metal-Semiconductor Field Effect Transistors (MESFETs) into a silicon photonics platform without process change is shown. This integration enables enhanced control functionality with minimal overhead. The critical final piece for a silicon photonics platform, adding a light source, is demonstrated along with performance results of the resulting tunable, extended C-band laser. In Part III, previous work on an enhanced silicon photonics platform with complementary components is used to build a high-speed integrated coherent link and then tested with a silicon photonics-based tunable laser. The transceiver was shown to operate at 34 Gbaud dual-polarization 16-QAM for a total of 272 Gbps over a single channel. This was the first published demonstration of an integrated coherent where all of the optics were built in a silicon photonics platform.