The new version includes new transmitters, receivers and DSP components for end-to-end 16-QAM, DP-16-QAM and DP-QPSK coherent optical system design and performance analysis. New visualizer components have also been introduced, including dual port visualizers which will allow users to perform simultaneous waveform analysis of any two independent binary, optical or electrical signals. NEW LIBRARY COMPONENTS OPTICAL TRANSMITTERS: 16-QAM, DP-16-QAM Two new components (16-QAM Transmitter, Optical DP-16-QAM Transmitter) have been added to the Optical Transmitters library. The 16-QAM Transmitter simulates a single channel optical transmitter with a 16-QAM modulation format. The Optical DP-16-QAM Transmitter component simulates a single channel optical transmitter with a dual polarization 16-QAM modulation format. Optical System 16-QAM Transmitter: The 16-QAM signal is generated by using MZ modulators to translate the QAM symbols onto an optical carrier. Each modulator branch modulates the in-phase (I) and quadrature components (Q) of a carrier. In the example above, an external bit stream is used to initiate the sampled data set. Figure 1: 16-QAM Transmitter: The 16-QAM signal is generated by using MZ modulators to translate the QAM symbols onto an optical carrier. Each modulator branch modulates the in-phase (I) and quadrature components (Q) of a carrier. In the example above, an external bit stream is used to initiate the sampled data set. Optical System Optical DP-16-QAM Transmitter: A polarization beam splitter is used to create two orthogonal polarization components which are modulated separately by 16-QAM transmitters (similar to Fig 1) and then combined using a polarization beam combiner. In the example above, an internal bit stream is used to initiate the sampled data set Figure 2: Optical DP-16-QAM Transmitter: A polarization beam splitter is used to create two orthogonal polarization components which are modulated separately by 16-QAM transmitters (similar to Fig 1) and then combined using a polarization beam combiner. In the example above, an internal bit stream is used to initiate the sampled data set OPTICAL RECEIVERS: Optical Coherent 16-QAM, Optical Coherent DP-16-QAM Two new components (Optical Coherent 16-QAM Receiver, Optical Coherent DP-16-QAM Receiver) have been added to the Optical Receivers library. The Coherent 16-QAM Receiver simulates an optical coherent receiver for QAM signals based on a homodyne design. The Coherent DP-16-QAM Receiver simulates an optical coherent receiver for the dual-polarization of 16-QAM signals. Optical System Optical Coherent 16-QAM Receiver Figure 3: Optical Coherent 16-QAM Receiver: The optical coherent QAM receiver involves a homodyne receiver design. The component is formed by a set of 3 dB fiber couplers, a local oscillator laser, and balanced detection (to eliminate the local oscillator intensity noise). The resulting electrical outputs are then sent to an external QAM Sequence Decoder and M-ary Threshold Detector to retrieve the original bit sequence. Optical System Optical Coherent DP-16-QAM Receiver Figure 4: Optical Coherent DP-16-QAM Receiver: The optical coherent DP-16-QAM receiver includes a local oscillator (LO) laser polarized at 45 degrees relative to the polarization beam splitter. The received signal is separately demodulated by each LO component using two single polarization 16-QAM receivers. DIGITAL SIGNAL PROCESSING: DSP for DP-QPSK; DSP for DP-16-QAM Two new components (DSP for DP-QPSK, DSP for DP-16-QAM) have been added to the new Receivers/Digital Signal Processing library, in addition to the Viterbi-Viterbi feed forward phase recovery components (single port and dual port). These DSP components can be used to build DP-16-QAM and DP-QPSK coherent systems. The DSP for DP-QPSK includes a 2-bit down-sampler, a dispersion compensator, a polarization de-multiplexer using a constant modulus algorithm, and a dual-polarization carrier phase estimator using a Viterbi-Viterbi feed forward algorithm. The DSP for DP-16-QAM includes a 2-bit down-sampler, a dispersion compensator, a polarization de-multiplexer using radius-directed equalization, and a carrier phase estimator using decision directed carrier phase recovery. For a complete example of a DP-16-QAM or DP-QPSK coherent system, please refer to the “100 Gbps DP-QPSK DSP 800 km.osd” and “400Gbps DP-16-QAM DSP 100 km.osd” example projects in the Samples/Advanced modulation systems folder.