Arbitrary Digital Processing of THz-Bandwidth Signals Based on Optic-Electronic-Optic Interferometers - Phase 2 (INTERFERE2)

光-电-光(OEO)干涉仪灵活地扩展了传统Mach-Zehnder干涉仪(MZI)的功能，包括用于光波的线性、非线性甚至时变传递函数。传统的MZI在其一个或两个干涉仪臂中进行相当简单的光学操作后对光信号进行分裂和重组，而OEO干涉仪在其一个臂中包括数字相干接收器，随后进行数字信号处理和随后的电-光同相正交调制。无论何时要修改超宽带光信号内的特定光谱内容而不影响剩余信号，都可以使用这种结构。利用OEO干涉仪，可以干涉性地分出和替换例如光ODFM信号的各个光谱副载波，这一方法对于传统的基于滤波器的光分插复用器是不可行的。在优先计划第一阶段的干涉项目中首次实验验证了具有光学不透明处理路径的光学光学干涉仪的概念之后，所请求的INTERFERE2项目有以下目标来演示光学光学干涉仪的高级操作：1.探索作为具有相控环路的分插复用器的光学光学干涉仪的实时操作的新算法。具有相位稳定的外部光纤延迟线的单片集成光子收发电路。单个光电干涉仪超宽带工作范围的概念验证演示，例如在无色波分复用宽调谐本机振荡器实验中4.研究两个或多个光电干涉仪的并行工作，同时接入和宽带修改连续的光谱5.演示和评估结合集成芯片和实时FPGA实现的光电干涉仪与光电干涉仪，先进的组合电子-光子系统是该项目的核心，通过利用尖端的光子集成技术与高效的数字电子信号处理相结合来访问巨大的光学带宽，允许克服纯电子信号处理的基本限制。

An optic-electronic-optic (OEO) interferometer flexibly extends the functionality of conventional Mach-Zehnder interferometers (MZI) to include linear, non-linear, and even time-variant transfer functions for optical waves. While a conventional MZI splits and recombines an optical signal after rather simple optical operations either in one or in both of its interferometer arms, an OEO interferometer comprises a digital coherent receiver in one of its arms, followed by digital signal processing and subsequent electrical-to-optical inphase-quadrature modulation. Such a structure can be utilized whenever a certain spectral content within an ultrabroadband optical signal is to be modified without affecting remaining signal. With the OEO interferometer it will become possible to interferometrically drop and replace, e.g., individual spectral subcarriers of an optical ODFM signal, an approach which would not be feasible with a conventional filter-based optical add-drop multiplexer. After the first experimental proof-of-concept of an OEO interferometer with an optically opaque processing path within the INTERFERE project of the first phase of the priority programme, the requested INTERFERE2 project has the following objectives for demonstrating advanced operations with OEO-interferometers: 1. Exploring novel algorithms for real-time operation of an OEO interferometer as add-drop multiplexer with phase-control loop.2. Monolithically integrated photonic transceiver circuit with phase-stabilized external fiber delay line.3. Proof-of-concept demonstration of the ultrabroadband operation range of a single OEO interferometer, e.g. in a colorless WDM experiment with widely tunable local oscillator 4. Study on the parallel operation of two or more OEO interferometers with simultaneous accessing and broadband modification of a contiguous optical spectrum 5. Demonstration and evaluation of an OEO interferometer combining the integrated chip with the real-time FPGA implementation With the OEO interferometer, an advanced combined electronic-photonic system is the core of the project, allowing access to the huge optical bandwidth by utilizing leading edge photonic integration technology in combination with efficient digital electronic signal processing, allowing to overcome fundamental limitations of purely electronic signal processing.