研究了一种硅光子芯片空间光耦合系统，简化了集成光子芯片用光纤阵列耦合的方式，通过将1550 nm附近波段的光通过空间光学系统，经光栅耦合器垂直耦合进入集成光子芯片，经过波导与微环谐振腔实现光学传感，采用多模光纤收集出射能量，并进行温度传感测试。实验结果表明，用波长探测方式，得到自由光谱范围（FSR）为0.85 nm，Q值为16321的环形谐振腔直通端透射谱线。在温度传感测试中，其灵敏度达到127 pm/℃。通过进一步对比测试表明，空间光耦合与光纤阵列光耦合只在插入损耗方面有所差距，耦合系统可得到较好的温度传感测试结果。空间光耦合具有更换传感器芯片便捷，容易实现多通道测试等优点。

Femtosecond laser inscription or writing has been recognized as a powerful technique to engineer various materials toward a number of applications. By efficient modification of refractive indices of dielectric crystals, optical waveguides with diverse configurations have been produced by femtosecond laser writing. The waveguiding properties depend not only on the parameters of the laser writing but also on the nature of the crystals. The mode profile tailoring and polarization engineering are realizable by selecting appropriate fabrication conditions. In addition, regardless of the complexity of crystal refractive index changes induced by ultrafast pulses, several three-dimensional geometries have been designed and implemented that are useful for the fabrication of laser-written photonic chips. Some intriguing devices, e.g., waveguide lasers, wavelength converters, and quantum memories, have been made, exhibiting potential for applications in various areas. Our work gives a concise review of the femtosecond laser-inscribed waveguides in dielectric crystals and focuses on the recent advances of this research area, including the fundamentals, fabrication, and selected photonic applications.

Entanglement is one of the most vital properties of quantum mechanical systems, and it forms the backbone of quantum information technologies. Taking advantage of nano/microfabrication and particularly complementary metal-oxide-semiconductor manufacturing technologies, photonic integrated circuits (PICs) have emerged as a versatile platform for the generation, manipulation, and measurement of entangled photonic states. We summarize the recent progress of quantum entanglement on PICs, starting from the generation of nonentangled and entangled biphoton states, to the generation of entangled states of multiple photons, multiple dimensions, and multiple degrees of freedom, as well as their applications for quantum information processing.

提出了一种由光生本振单元和波长分离调制单元组成的微波光子混频方法，并在绝缘体上硅材料上设计实现了上述波长分离调制芯片。该芯片集成了硅基相位调制器、微环滤波器、光电探测器、光耦合器和光栅耦合器。实验搭建了基于该波长分离调制芯片的微波光子次谐波混频系统，结果表明，该微波光子混频器可以将6~16 GHz的RF信号变频到33~23 GHz。此外，针对实验系统中残留的混频杂散，分别提出了增加微环滤波器抑制比降低泄露光生本振强度和引入光移相器修正泄漏光生本振相位两种解决方案。通过仿真验证可知，引入光移相器的方法更为简单，更适合于光子集成芯片。

光子人工智能芯片以光速执行运算，且具有低功耗、延迟低、抗电磁干扰的优势。小型化与集成化是实现这一技术革新的关键步骤。本文将光刻技术运用于衍射光栅的制作，提出一种基于10.6微米激光的全光衍射深度学习神经网络光栅设计及实现方法。由于光源波长由毫米波向微米波进化，神经元的特征尺度缩小至20微米，与现有光衍射神经网络相比，深度学习神经网络特征尺寸缩小了80倍，为进一步实现光子计算芯片大规模集成奠定了基础。