Performance Breakthrough in Distributed Fiber Sensing by Digital Signal Processing of Optical Signal Amplitude and Phase

基于光纤的传感器是一种敏感而坚固的设备，对恶劣的外部环境波动(如温度、电磁干扰、辐射等)具有弹性。并在基础设施中很好地作为分布式传感介质。它们通常用于制造过程的高端校准和控制，典型的部署包括笨重的频谱分析仪(电或光学)和昂贵的可调谐激光光源。拟议的研究将通过应用检测方案和信号处理技术来解决这些挑战，这些方案和信号处理技术已经彻底改变了有线和无线技术中的数字通信。信息将在光信号的幅度和相位中进行编码，以提高其对不断变化的环境的敏感度，同时消除在收发信机上增加硬件的需要。由于与典型的无线(MHz)/有线(GHz)通道的带宽需求相比，环境条件的变化相对较慢(KHz)，因此最初用于数字通信的相应成熟的半导体集成电路(高速电子)以极低的成本提供了巨大的计算能力。通过通信和成像中常见的成熟数字信号处理(DSP)技术，可以使用多余的计算带宽来补偿设备伪影。这将在分布式光纤传感器的性能和复杂性方面带来数量级的改进。

Optical fiber based sensors are sensitive and robust devices that are resilient to harsh external environment fluctuations (e.g. temperature, electromagnetic interference, radiation etc.) and serve well as a distributed sensing medium in infrastructure. Often used for high end calibration and control of manufacturing processes, their typical deployment involves bulky spectrum analyzers (electrical or optical), and costly tunable laser sources.The proposed research will address these challenges by applying detection schemes and signal processing techniques that have revolutionized digital communications in both wireline and wireless technologies. Information will be encoded in both the amplitude and phase of the optical signal to increase its sensitivity to the changing ambient environment, while removing the need for additional hardware at the transceivers. Estimation and calibration strategies will be developed to compensate for optical device fabrication defects and variations.As the environmental conditions vary relatively slowly (kHz) compared to the bandwidth requirement of a typical wireless (MHz)/ wireline (GHz) channel, the correspondingly matured semiconductor integrated circuit (highspeed electronic) originally intended for digital communications provides dramatic computation power at an extremely low cost. The excess computing bandwidth can be used to compensate for device artefacts via mature digital signal processing (DSP) technique common in communication and imaging. This will deliver orders of magnitude improvement in the performance and complexity reduction in distributed optical fiber sensors.