Optical: Robust, Spectrally Efficient Optical Fiber Transmission Techniques: Nonlinear Analysis, Coded Modulation Techniques and System Experiments

随着光纤系统迅速接近二进制调制和直接检测的极限，替代调制、编码和检测技术将发挥越来越大的作用。这个项目将通过几个方面来解决这一演变：分析非线性DPSK、PSK和QAM系统。差分相移键控(DPSK)、相移键控(PSK)和正交幅度复用(QAM)提供了更高的频谱效率和稳健性。光纤克尔非线性从根本上限制了系统性能，但通常使用蒙特卡罗模拟进行研究。将开发使用这些调制技术来计算非线性系统中的差错概率的解析技术。这些分析将为系统优化提供洞察力，并将产生实用的工程设计标准。非线性相位噪声：分析与补偿。当信号和放大器噪声通过克尔效应共同调制光纤折射率时，产生了非线性相位噪声。NLPN潜在地限制了使用DPSK、PSK或QAM的系统。将对NLPN进行解析描述，并演示补偿NLPN的电气技术。编码的非二进制调制技术。当前的光学系统使用与二进制调制匹配的二进制调制和编码方案。为了充分发挥非二进制调制的优势，需要研究合适的编码技术，包括网格编码调制和Turbo编码调制。系统实验。PSK的相干检测将使用基于MEMS的外腔激光器来执行。这些实验将验证非线性系统分析，测试NLPN的电气补偿，并证明相干检测可以在频谱效率和稳健性方面产生实质性的改善。这个项目将做出几个更广泛的贡献，通过教育不同背景和性别的学生，让本科生参与研究，以及培训未来的教育工作者。结果将被纳入研究生水平的讲座和实验室课程。

0335013Kahn As optical fiber systems rapidly approach the limits of binary modulation and direct detection, alternative modulation, coding and detection techniques will play increasing roles. This project will address this evolution with several thrusts: Analysis of nonlinear DPSK, PSK and QAM systems. Differential phase-shift keying (DPSK), phase-shift keying (PSK) and quadrature-amplitude multiplexing (QAM) offer increased spectral efficiency and robustness. Fiber Kerr nonlinearity fundamentally limits system performance, but is typically studied using Monte Carlo simulation. Analytical techniques to compute error probability in nonlinear systems using these modulation techniques will be developed. These analyses will provide insight into system optimization and will yield practical engineering design criteria. Nonlinear phase noise: analysis and compensation. Nonlinear phase noise (NLPN) arises when signal and amplifier noise together modulate the fiber refractive index via the Kerr effect. NLPN potentially limits systems using DPSK, PSK or QAM. NLPN will be characterized analytically, and electrical techniques to compensate NLPN will be demonstrated. Coded nonbinary modulation techniques. Current optical systems use binary modulation and coding schemes matched to binary modulation. In order to realize the full benefits of nonbinary modulation, appropriate coding techniques will be investigated, including trellis-coded modulation (TCM) and turbo TCM. System experiments. Coherent detection of PSK will be performed using MEMS-based external-cavity lasers. These experiments will verify the nonlinear system analysis, test electrical compensation of NLPN, and demonstrate that coherent detection can yield substantial improvements in spectral efficiency and robustness. This project will make several broader contributions, by educating students from diverse backgrounds and genders, involving undergraduate students in research, and training future educators. Results will be incorporated into graduate-level lecture and laboratory courses.