We propose a joint look-up-table (LUT)-based nonlinear predistortion and digital resolution enhancement scheme to achieve high-speed and low-cost optical interconnects using low-resolution digital-to-analog converters (DACs). The LUT-based predistortion is employed to mitigate the pattern-dependent effect (PDE) of a semiconductor optical amplifier (SOA), while the digital resolution enhancer (DRE) is utilized to shape the quantization noise, lowering the requirement for the resolution of DAC. We experimentally demonstrate O-band intensity modulation and direct detection (IM/DD) transmission of 124-GBd 4 / 6-level pulse-amplitude modulation ( PAM ) -4 / 6 and 112-GBd PAM-8 signals over a 2-km standard single-mode fiber (SSMF) with 3 / 3.5 / 4-bit DACs. In the case of 40-km SSMF transmission with an SOA-based preamplifier, 124-GBd on-off-keying (OOK)/PAM-3/PAM-4 signals are successfully transmitted with 1.5 / 2 / 3-bit DACs. To the best of our knowledge, we have achieved the highest net data rates of 235.3-Gb / s PAM-4, 289.7-Gb / s PAM-6, and 294.7 Gb / s PAM-8 signals over 2-km SSMF, as well as 117.6-Gb / s OOK, 173.8-Gb / s PAM-3, and -231.8 Gb / s PAM-4 signals over 40-km SSMF, employing low-resolution DACs. The experimental results reveal that the joint LUT-based predistortion and DRE effectively mitigate the PDE and improve the signal-to-quantization noise ratio by shaping the noise. The proposed scheme can provide a powerful solution for low-cost IM/DD optical interconnects beyond 200 Gb / s.

Excitons have significant impacts on the properties of semiconductors. They exhibit significantly different properties when a direct semiconductor turns in to an indirect one by doping. Huybrecht variational method is also found to influence the study of exciton ground state energy and ground state binding energy in Al_xGa_1?xAs semiconductor spherical quantum dots. The Al_xGa_1?xAs is considered to be a direct semiconductor at Al concentration below 0.45, and an indirect one at the concentration above 0.45. With regards to the former, the ground state binding energy increases and decreases with Al concentration and eigenfrequency, respectively; however, while the ground state energy increases with Al concentration, it is marginally influenced by eigenfrequency. On the other hand, considering the latter, while the ground state binding energy increases with Al concentration, it decreases with eigenfrequency; nevertheless, the ground state energy increases both with Al concentration and eigenfrequency. Hence, for the better practical performance of the semiconductors, the properties of the excitons are suggested to vary by adjusting Al concentration and eigenfrequency

In this work, a novel one-time-programmable memory unit based on a Schottky-type p-GaN diode is proposed. During the programming process, the junction switches from a high-resistance state to a low-resistance state through Schottky junction breakdown, and the state is permanently preserved. The memory unit features a current ratio of more than 10³, a read voltage window of 6 V, a programming time of less than 10^?4 s, a stability of more than 10⁸ read cycles, and a lifetime of far more than 10 years. Besides, the fabrication of the device is fully compatible with commercial Si-based GaN process platforms, which is of great significance for the realization of low-cost read-only memory in all-GaN integration.

由于硫系玻璃具有良好的光学性质，在非线性光学等方面研究广泛，但基于硫系玻璃光电探测器的相关研究却很少。本文利用真空共热蒸发技术制备了不同掺银比例的硫系玻璃薄膜作为半导体膜层结构，并设计构建了金属-绝缘体-半导体结构的自供电光电探测器，探究了该光电探测器的响应光谱范围。结果表明，该探测器对可见光到近红外区域的光均有响应。针对掺银硫系玻璃光电探测器在635 nm波长激光下，研究了探测器响应电压与激发功率之间的关系。当激光功率小于10 mW时，探测器响应电压与激发功率线性相关；当激光功率大于10 mW时，探测器响应电压逐渐饱和。探测器的上升和衰减时间分别为3.932 s和1.522 s。本研究为硫系玻璃材料在自供电光电探测器领域的应用提供了证明。

将一个808 nm宽发射区半导体激光器应用于纵模选择束腰劈裂偏振合束外腔中，实现了高光束质量、高亮度和窄线宽的激光输出。所获激光输出功率为5.08 W，快慢轴光束质量M²=1.85×18.2，慢轴光束质量较自由运转激光器提高48%，输出激光亮度B=22.74 MW·cm^-2·sr^-1，是原激光器自由运转的1.3倍。所获激光光谱线宽为0.47 nm，压缩至原激光器自由运转的光谱宽度的0.14。

基于宽禁带光导半导体的固态光导微波源是高功率微波产生的一种新途径，该方案具有功率密度高、频带范围宽等特点，且其低时间抖动特性使其在功率合成方面具有巨大潜力，利用光波束形成网络构建光导微波有源相控阵是光导微波器件迈向实用的重要途径。分析了光导微波相控阵系统原理，设计了光导微波真延时网络架构，并构建了差分真延时相控阵和考虑相位随机误差的真延时相控阵的理论模型，对影响功率合成和波束扫描的关键因素开展定量分析和仿真验证。结果表明，对于发射1 GHz信号的n×10阵列，延时均方差在10 ps以下时，指向偏差小于0.13°，峰值增益损耗小于2%；延时步进精度在10 ps以下时，指向偏差小于0.2°，峰值增益损耗小于0.03%。由此提出延时精度指标，为未来更高功率、更大规模的光导微波合成技术发展提供参考。

目前针对常见爆炸物三硝基甲苯 (TNT) 的检测越来越受到重视。本研究采用低成本的芴基发绿光共轭聚合物（FGEP）研制荧光淬灭传感器用于检测TNT。实验研究了FGEP在不同溶液浓度下形成的不同厚度薄膜对TNT淬灭的效率，实验结果表明浓度为0.5 mg/mL (厚度为19.50 nm) 的样品薄膜在TNT蒸气中淬灭效率最大达到71.71%, 基于此淬灭效率最高的样品薄膜的研究发现：该薄膜对TNT的响应具有良好的可逆性；激发光强度为16.5 mW时，荧光淬灭效率最佳；最后开展了样品在TNT作用下与光漂白作用下的实验研究。研究结果为后续实现一种低成本、易于制备、可重复性高且有利于工程化的爆炸物传感器提供了一定基础。