Multi-channel detection is an effective way to improve data throughput of spectral-domain optical coherence tomography (SDOCT). However, current multi-channel OCT requires multiple detectors, which increases the complexity and cost of the system. We propose a novel multi-channel detection design based on a single spectrometer. Each camera pixel receives interferometric spectral signals from all the channels but with a spectral shift between two channels. This design effectively broadens the spectral bandwidth of each pixel, which reduces relative intensity noise (RIN) by √M times with M being the number of channels. We theoretically analyzed the noise of the proposed design under two cases: shot-noise limited and electrical noise or RIN limited. We show both theoretically and experimentally that this design can effectively improve the sensitivity, especially for electrical noise or RIN-dominated systems.

设计并制作了一种高灵敏度且制作简单的聚甲基丙烯酸甲酯（Polymethyl Methacrylate，PMMA）微球与单模光纤复合的湿度传感器。该光纤湿度传感器由PMMA微球与单模光纤构成。由于在微球中形成了法布里-珀罗腔，当外界环境湿度升高时，PMMA微球吸收水分子体积膨胀，导致法布里-珀罗腔的腔长增长，使得传感器干涉光谱的波峰（谷）发生红移，从而实现湿度传感。对所制作传感器的湿度响应、稳定性和重复性等进行了实验研究，实验结果表明：在30%~80%湿度范围内，该湿度传感器的灵敏度达173.36 pm/%RH，波长漂移随相对湿度变化呈良好的线性关系，其线性度达0.992 26，且具有良好的稳定性和重复性。该PMMA微球与单模光纤复合的湿度传感器具有灵敏度高、结构简单、无需镀膜且易于制作的优点。

高温应变传感器在航空航天、石油勘探、工业冶炼等领域有巨大的潜在需求。传统的电学类传感器受限于其电学原理和材料特性，无法长时间在高温、高压、强电磁干扰、化学腐蚀等恶劣环境下保持精确测量。基于此，国内外研究团队对光纤高温应变传感器进行了大量研究，在提升传感器的耐温性能和提高传感器的应变灵敏度等方面取得了一系列成果。本文综述了基于光纤布拉格光栅型、光纤干涉型高温应变传感器的传感机理、实验方法及封装应用的研究现状，总结了不同传感机理对温度、应变的响应特性，重点介绍了光纤高温应变传感器的最新进展，并对光纤高温应变传感器的未来发展方向进行了展望。