To date, fluorescence imaging systems have all relied on at least one beam splitter (BS) to ensure the separation of excitation light and fluorescence. Here, we reported SiO2/TiO2 multi-layer long pass filter integrated GaN LED. It is considered as the potential source for imaging systems. Experimental results indicate that the GaN LED shows blue emission peaked at 470.3 nm and can be used to excite dye materials. Integrating with a long pass filter (550 nm), the light source can be used to establish a real-time fluorescence detection for dyes that emit light above 550 nm. More interestingly, with this source, a real-time imaging system with signature words written with the dyes, such as ‘N J U P T’, can be converted into CCD images. This work may lead to a new strategy for integrating light sources and BS mirrors to build mini and smart fluorescence imaging systems.

针对不同项目研制过程中碲镉汞线列光导器件在筛选测试和应用中出现的失效模式进行了归纳和总结，并综合碲镉汞材料参数、器件结构尺寸、器件物理、器件制备工艺和器件测试等几个方面因素对器件失效的可能原因进行了分析，首次提出碲镉汞线列光导器件的优值因子作为失效判据，为进一步理解碲镉汞线列光导器件的物理机理以及更好优化器件的筛选过程提供了参考，为碲镉汞线列光导器件应用中出现的失效问题提供了分析和解决的方向。

由于低信噪比的小样本太赫兹光谱的可区分性特征提取困难和样本量过少带来的深度学习模型自身的过拟合问题，将太赫兹光谱与深度学习相结合应用于心肌淀粉样变检测仍面临挑战。本文提出了一种基于多模块顺序级联的分类模型，用于心肌淀粉样变在算法层面的实时检测。首先，采集了少量的低信噪比太赫兹光谱并对其进行预处理。其次，构建了一个基于卷积降噪自编码器、多尺度特征提取模块、密集连接模块的深度学习模型。最后，通过五折交叉验证策略进行病变预测，以获得稳定、可靠的结果。 10次独立重复实验和对比实验结果表明，该方法能对含噪光谱进行准确、稳定的分类，且其综合指标更优。不同样本量下的实验表明，本方法对样本量变化具有适应性：数据量为100时可达到95%的准确率；数据量仅为20时，该模型仍能取得70%的准确率。该项工作对心肌淀粉样变的实时、高效、安全诊断具有重要意义。

针对当前视觉检测系统LED光源照度优化研究中存在的照度效果评价因素单一、照度优化方法通用性不足等问题，以芯片封装质量视觉检测为例，提出一种基于改进樽海鞘算法的LED光源照度优化方法。该方法在单个LED光源照度数学模型基础上，建立标准条形LED阵列光源照度数学模型，获取条形LED阵列在任意空间位姿与被测面的照度值；基于照度均匀度、照度梯度变化与对中度、平均照度、目标与背景区分度等因素建立平面照度效果评价函数；提出改进樽海鞘算法，通过改进算法收敛系数、速度、领导者与追随者位置等更新策略，增强区域搜索的多样性；应用改进樽海鞘算法对平面照度效果评价函数进行优化求解，获取具有最优照度效果的空间位姿参数。实验结果表明：考察优化区域的相对照度分布，文中提出的LED光源照度优化方法所得照度分布与实际测量所得照度分布结果基本一致，目标区域理论照度均匀度在98.78%以上，误差在5.57%以内。因此文中提出方法优化目标合理，可用于视觉检测系统具有最优照度效果时光源位姿信息参数的获取。

Temporal and spatial resonant modes are always possessed in physical systems with energy oscillation. In ultrafast fiber lasers, enormous progress has been made toward controlling the interactions of many longitudinal modes, which results in temporally mode-locked pulses. Recently, optical vortex beams have been extensively investigated due to their quantized orbital angular momentum, spatially donut-like intensity, and spiral phase front. In this paper, we have demonstrated the first to our knowledge observation of optical vortex mode switching and their corresponding pulse evolution dynamics in a narrow-linewidth mode-locked fiber laser. The spatial mode switching is achieved by incorporating a dual-resonant acousto-optic mode converter in the vortex mode-locked fiber laser. The vortex mode-switching dynamics have four stages, including quiet-down, relaxation oscillation, quasi mode-locking, and energy recovery prior to the stable mode-locking of another vortex mode. The evolution dynamics of the wavelength shifting during the switching process are observed via the time-stretch dispersion Fourier transform method. The spatial mode competition through optical nonlinearity induces energy fluctuation on the time scale of ultrashort pulses, which plays an essential role in the mode-switching dynamic process. The results have great implications in the study of spatial mode-locking mechanisms and ultrashort laser applications.

We experimentally demonstrate two kinds of all few-mode fiber (FMF) ring lasers with high-order mode (HOM) oscillation in the laser cavity. One kind is a switchable-wavelength all-FMF HOM laser with an output of tunable optical vortex beams (OVBs); the other is a Q-switched all-FMF HOM laser with an output of pulsed cylindrical vector beams (CVBs). The lasers are composed of all-FMF components and few-mode erbium-doped fiber. A Sagnac interferometer made of a 3 dB FMF coupler functions as the wavelength selector, and switchable multiwavelength tunable OVBs are experimentally realized. Carbon nanotube-based saturable absorbers and the nonlinear polarization rotation technique are used to achieve Q-switched CVB lasers. This is the first report, to our knowledge, on the generation of switchable-wavelength and Q-switched HOM beams in all-FMF laser cavities.