随着旋转调制惯导系统精度的不断提升，单次导航实验周期越来越长，试验周期急剧增加，为试验鉴定和评估带来了困难。为合理评价长航时旋转调制惯导系统的导航精度，首先介绍了一种兼具自标定、自对准功能和导航功能的一体式旋转调制方案，将惯导系统自标定、自对准状态和导航过程中的旋转路径进行统一；然后提出了一种基于重复样本的长航时旋转调制惯导系统长周期导航测试方法，该方法可以更高效快捷地完成所需全部导航测试评估任务；最后，利用实验室30天的长航时导航测试数据进行了实验验证，最大定位误差为0.71（归一化），与独立航次统计结果相当，同时利用车载动态试验验证明了该方法的有效性和可行性。该方法可以大幅缩短导航系统测试的周期，为长航时惯导装备研制和试验测试评估提供有效手段。

Ultrashort pulses at 920 nm are a highly desired light source in two-photon microscopy for the efficient excitation of green fluorescence protein. Although Nd^{3 +} -doped fibers have been utilized for 920-nm ultrashort pulse generation, the competitive amplified spontaneous emission (ASE) at 1.06 μm remains a significant challenge in improving their performance. Here, we demonstrate a coordination engineering strategy to tailor the properties of Nd^{3 +} -doped silica glass and fiber. By elevating the covalency between Nd^{3 +} and bonded anions via sulfur incorporation, the fiber gain performance at 920 nm is enhanced, and 1.06-μm ASE intensity is suppressed simultaneously. As a result, the continuous-wave laser efficiencies and signal-to-noise ratio at 920 nm by this fiber are significantly enhanced. Importantly, the stable picosecond pulses at 920 nm are produced by a passive mode-locking technique with a fundamental repetition rate up to 207 MHz, which, to the best of our knowledge, is the highest reported repetition rate realized by Nd^{3 +} -doped silica fibers. The presented strategy enriches the capacity of Nd^{3 +} -doped silica fiber in generating 920-nm ultrashort pulses for application in biophotonics, and it also provides a promising way to tune the properties of rare-earth ion-doped silica glasses and fibers toward ultrafast lasers.

This paper investigates the monolithic edge-cladding process for the elliptical disk of N31-type Nd-doped phosphate laser glass, which will be utilized under liquid cooling conditions for high-power laser systems. The thermal stress, interface bubbles and residual reflectivity, which are due to high-temperature casting and bonding during the monolithic edge-cladding process, are simulated and determined. The applied mould is optimized to a rectangular cavity mould, and the casting temperature is optimized to 1000°C. The resulting lower bubble density makes the mean residual reflectivity as low as 6.75 × 10^-5, which is enough to suppress the amplified spontaneous emission generated in the Nd-glass disk, and the resulting maximum optical retardation is converged to 10.2–13.3 nm/cm, which is a favourable base for fine annealing to achieve the stress specification of less than or equal to 5 nm/cm. After fine annealing at the optimized 520°C, the maximum optical retardation is as low as 4.8 nm/cm, and the minimum transmitted wavefront peak-to-valley value is 0.222 wavelength (632.8 nm). An N31 elliptical disk with the size of 194 mm × 102 mm × 40 mm can be successfully cladded by the optimized monolithic edge-cladding process, whose edge-cladded disk with the size of 200 mm × 108 mm × 40 mm can achieve laser gain one-third higher than that of an N21-type disk of the same size.

“燕尾”状缺陷是异质外延碲镉汞薄膜中一种形状、朝向统一的典型缺陷，本文对“燕尾”状缺陷的表面形貌、结构及形成机理进行了表征及研究。结果表明，在碲镉汞薄膜表面，“燕尾”状缺陷以两条凸起的“燕尾”边为特征形貌。在碲镉汞薄膜中，“燕尾”状缺陷为倒金字塔结构，由(11ˉ1ˉ)、1ˉ1ˉ1、(11ˉ1)、(111ˉ)四个底面与（211）表面围成。“燕尾”状缺陷为（552）A孪晶缺陷，（552）A孪晶与（211）A基体间不同的生长速率导致了缺陷的形成。碲镉汞晶体中12个滑移系统间不同的Schmid因子决定了（552）A孪晶成核生长于1ˉ1ˉ1和(11ˉ1)面，也决定了“燕尾”状缺陷的表面形貌及结构。

A novel four light ray path test method for measuring residual reflectance has been presented. Residual reflectance spatial distribution at a cladding interface was measured using the technique. Residual reflectance could be on the order of 10^?5 by matching the refractive index of Nd:glass, polymer, and cladding glass and eliminating defects in the adhesive layer. Residual reflection spatial distribution appears to be similar to Newton rings due to the edge surface flatness. The relationship between the residual reflectance and the edge surface flatness was discussed, and the results revealed that the edge surface flatness is very important during the cladding process.