随着星间通信系统的迅速发展，数据传输的精度要求不断提高。分光镜作为系统的核心元件，其光谱特性和面形精度直接影响整个系统的传输精度。本文基于薄膜干涉理论，选取Ta₂O₅与SiO₂作为高低折射率膜层材料进行膜系设计，采用电子束蒸发的方式在石英基板上制备高精度分光镜。同时根据膜层应力补偿原理建立面形修正模型，修正分光镜面形。光谱分析仪检测结果显示，分光镜在入射角度为21.5°～23.5°内，1563 nm透过率大于98%，1540 nm反射率大于99%。激光干涉仪检测结果显示，分光镜反射面形精度RMS由λ/10修正至λ/90（λ=632.8 nm），透过面形精度RMS为λ/90。

有机电致发光器件（Organic light emitting diode，OLED）具有轻薄、便于携带、自发光、能耗低、亮度更大、柔性显示等特点，可以增加显示产品的附加值，因此被科学和产业界广泛关注。然而，OLED器件中的有机材料对空气中的水汽和氧气十分敏感，若器件在无封装保护的情况下长期在空气中存放，将会严重影响OLED的工作性能和寿命。除了选择合适的传输层材料、表面层结构和利用界面工程提高材料水氧耐受能力之外，对器件进行可靠的封装是隔绝空气中水汽和氧气侵蚀的一种有效手段。原子层沉积（Atomic layer deposition，ALD）是一种已经在实验室验证的有效薄膜沉积封装技术，由于ALD的自限制反应特性，可以在低温下沉积出厚度精确可控且均匀致密的薄膜，利用ALD沉积的薄膜往往拥有良好的机械柔性、超高的阻隔性能和光学透过率。本文将回顾原子层沉积技术的原理，分析ALD制备薄膜的水汽透过率，比较ALD在单层、有机‐无机叠层薄膜封装制备上的技术优势。

In this work, a soliton mode-locked erbium-doped fiber laser (EDFL) with a high-quality molecular beam epitaxy (MBE)-grown topological insulator (TI) Bi₂Se₃ saturable absorber (SA) is reported. To fabricate the SA device, a 16-layer Bi₂Se₃ film was grown successfully on a 100 μm thick SiO₂ substrate and sandwiched directly between two fiber ferrules. The TI-SA had a saturable absorption of 1.12% and a saturable influence of 160 MW/cm². After inserting the TI-SA into the unidirectional ring-cavity EDFL, self-starting mode-locked soliton pulse trains were obtained at a fundamental repetition rate of 19.352 MHz. The output central wavelength, pulse energy, pulse duration, and signal to noise ratio of the radio frequency spectrum were 1530 nm,18.5 pJ, 1.08 ps, and 60 dBm, respectively. These results demonstrate that the MBE technique could provide a controllable and repeatable method for the fabrication of identical high-quality TI-SAs, which is critically important for ultra-fast pulse generation.

Broadband transient reflectivity traces were measured for Bi2Se3 thin films with various substrates via a 400 nm pump–white-light-probe setup. We have verified the existence of a second Dirac surface state in Bi2Se3 and qualitatively located it by properly analyzing the traces acquired at different probe wavelengths. Referring to the band structure of Bi2Se3, the relaxation mechanisms for photo-excited electrons with different energies are also revealed and studied. Our results show a second rise of the transient reflection signal at the time scale of several picoseconds. The types of substrate can also significantly affect the dynamics of the rising signal. This phenomenon is attributed to the effect of lattice heating and coherent phonon processes. The mechanism study in this work will benefit the fabrication of high-performance photonic devices based on topological insulators.