本文提出并研究了一种基于干涉增强型混合光波导（IE-HOW）的高灵敏折射率传感器。IE-HOW包括微纳U型光波导与微瓶腔，通过光纤熔融拉锥以及电弧放电方法制备并级联而成。基于强倏逝场效应，实现了对折射率的高灵敏传感测试。实验结果表明，当微纳U型光纤锥区直径为4.88 μm时，IE-HOW的折射率灵敏度相比于普通单个无干涉增强微纳U型光波导提高了3倍，高达8813.26 nm/RIU（灵敏度单位），线性度R²>0.9。该传感器具有灵敏度高、损耗低、结构紧凑、稳定性好等优点，在环境监测、生化检测、临床诊断等领域有着广阔的应用前景。

通过传统的熔融淬火技术以及后续热处理法制备了Tm³⁺/Yb³⁺共掺含LaF₃纳米晶锗酸盐微晶玻璃。通过DTA和XRD研究其热性质和LaF₃纳米晶的可控析出。通过透过光谱和上转换发光光谱研究了玻璃的光学性能。利用荧光强度比（FIR）技术研究了微晶玻璃样品在980 nm激光激发下的上转换发光光谱与温度的依赖关系。研究发现，该微晶玻璃样品在313~573 K温度范围内的最大绝对灵敏度S_a和最大相对灵敏度S_r分别为2.6×10^-4 K^-1（573 K）和2.3×10^-2 K^-1（313 K）。结果表明，Tm³⁺/Yb³⁺共掺含LaF₃纳米晶锗酸盐微晶玻璃在温度传感领域具有潜在的应用前景。

High-performance thin film lithium niobate (LN) electro-optic modulators with low cost are in demand. Based on photolithography and wet etching, we experimentally demonstrate a thin film LN Mach–Zehnder modulator with a 3 dB bandwidth exceeding 110 GHz, which shows the potential of boosting the throughput and reducing cost. The fabricated modulator also exhibits a comparable low half-wave voltage-length product of ∼2.37V·cm, a high extinction ratio of >23dB, and the propagation loss of optical waveguides of ∼0.2dB/cm. Besides, six-level pulse amplitude modulation up to 250Gb/s is successfully achieved.

Hollow-core fiber (HCF) promises to unify air-borne light propagation and non-line-of-sight transmission, thus holding great potential for versatile photonics-based quantum information applications. The early version of HCF based on photonic-bandgap guidance has not proven itself a reliable quantum channel because of the poor modal purity in both spatial and polarization domains, as well as significant difficulty in fabrication when the wavelength shifts to the visible region. In this work, based on the polarization degree of freedom, we demonstrate high-fidelity (～0.98) single-photon transmission and distribution of entangled photons over a 36.4 m hollow-core conjoined-tube fiber (CTF) by using commercial silicon single-photon avalanche photodiodes. Our CTF realizes the combined merits of low loss, high spatial modal purity, low polarization degradation, and low chromatic dispersion. We also demonstrate single-photon low-latency (～99.96% speed of light in vacuum) transmission, paving the way for extensive uses of HCF links in versatile photonics-based quantum information processing.